US3561618A

US3561618A - Article storage and transfer arrangement for programmed manipulators

Info

Publication number: US3561618A
Application number: US803158*A
Authority: US
Inventors: Torsten H Lindbom
Original assignee: Unimation Inc
Current assignee: Unimation Inc
Priority date: 1969-02-28
Filing date: 1969-02-28
Publication date: 1971-02-09
Anticipated expiration: 1988-02-09

Abstract

A series of programmed manipulators each having an article transfer arm are provided at different work stations to perform different work operations on a batch of articles. The articles are stored in and transferred between work stations in a magazine assembly which is capable of maintaining all of the parts in a predetermined orientation at each work station. Furthermore, the magazine assembly cooperates with the programmed manipulator at a particular work station to sequentially position each article in the batch to a predetermined position and with a predetermined orientation so that the article can be grasped by the manipulator, worked on, and redeposited in the magazine without human assistance.

Description

I United States Patent l 13,561,618

[72] lnventor Torsten H. Lindbom [56] References Cited Newmwn Conn- UNITED STATES PATENTS P 803l58 3,250,208 5/1966 Rainbow 214/310x {22 Wed 3 261 131 7/1966 Loh et al 214/89 [45] Patented Feb. 9, 1971 [73] Assignee Unimation, lnc. Primary Examiner-Albert J. Makay Bethel, Conn. AttorneyMason, Kolehmainen, Rathburn & Wyss a corporation of Delaware ABSTRACT: A series of programmed manipulators each having an article transfer arm are provided at different work sta- ARTICLE STORAGE AND TRANSFER tions to perform different work operations on a batch of arti- ARRANGEMENT FOR PROGRAMME) cles. The articles are stored in and transferred between work M ANIPUL ATORS stations in a magazine assembly which is capable of maintain- 6 Cl 18 D ing all of the parts in a predetermined orientation at each work aims rawmg station. Furthermore, the magazine assembly cooperates with [52] US. Cl 214/ 16.4, the programmed manipulator at a particular work station to 214/1 sequentially position each article in the batch to a predeter- [51] Int. Cl B65g 1/00 mined position and with a predetermined orientation so that [50] Field of Search 214/ I 6.4, the article can be grasped by the manipulator, worked on, and

redeposited in the magazine without human assistance.

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ARTICLE STORAGE AND TRANSFER ARRANGEMENT FOR PROGRAMMED MANIPULATORS The present invention relates to acticle-handling systems and, more particularly, to an article storage and transfer arrangement for programmed manipulators.

Programmed article transfer apparatus or manipulators are being used in an increasing number of applications today to perform operations on a series of articles in accordance with a predetermined or programmed series of movements. Such programmed manipulators are provided with an article transfer are equipped to grasp an article of a particular size or shape and move the article sequentially to a series of positions at which various work operations may be performed on the article. The programmed manipulator usually includes an electromagnetic memory drum which stores a number of command signals for moving the transfer arm to different positions and along different axes during a work cycle. The manipulator may first be taught to perform a sequence of movements by recording appropriate signals on the memory drum, and is thereafter capable of repetitively performing the recorded sequence so that the same operations may be made on a large number of identical parts or articles. Programmed manipulators of this type are described, for example, in U.S. Pat. Nos. 2,988,237; 3,279,624; 3,283,918; 3,306,442; and 3,306,471.

ln may instances different work operations must be performed on a batch of parts or articles at different work stations and a programmed manipulator is provided at each work station for automatic handling of the articles during the work operations at that particular workstation. While the handling of the articles is accomplished by the manipulator in a completely automatic manner at any given work station, if the articles are simply dumped into a tote box and carried to the next work station the orientation of the articles within the box is completely random and an operator is required to align the articles to a predetermined orientation at the new work station so that the programmed manipulator at that station can grasp each article sequentially and perform the desired work operations thereon. Such an-arrangement requires a large expenditure of labor in reorienting the articles at each new work station and detracts from the inherent labor-saving advantages of the manipulators themselves at each work station. Furthermore, the parts must be stored between operations, awaiting a machine to be set up for the next operation. Also, each operator must have readily at hand a continuing supply of parts to be worked and storage for the parts produced. A considerable amount of human attention and hand labor is thus required in present day arrangements for job lot or batch system operations where the production quantity is limited.

It is, therefore, an object of the present invention to provide a new and improved article storage and transfer arrangement which avoids the disadvantages of the prior arrangements described heretofore.

It is a further object of the invention to provide a new and improved article storage and transfer arrangement whereby a batch of articles may be sequentially fed to programmed manipulators at different work stations entirely automatically.

It is another object of the present invention to provide a new and improved articles storage and transfer arrangement wherein the articles are stored in a magazine assembly with predetermined orientation such that they may be sequentially presented to the transfer arm of the programmed manipulator with the correct orientation to be grasped thereby.

Another object of the present invention is to provide a new and improved magazine assembly which is operable in conjunction with the programmed transfer arm of a programmed manipulator and is adapted for sequentially orienting each part in the magazine into a predetermined position for handling by the arm.

Yet another object of the present invention is to prove provide a new and improved magazine assembly of the character described, which magazine is easily moved from one work station to another when fully loaded with a batch of parts.

Yet another object of the present invention is to provide a new and improved magazine assembly of the type and for the purpose described which magazines requires a minimum amount of hurri'an attention during operation thereof in conjunction with a programmed manipulator and requires a minimum of setup time in order to be readied for operation.

Yet another object of the present invention is to provide a new and improved magazine for the storage and transportw tion ofa batch of parts or articles, which magazine operates in a highly efficient manner, occupies a minimum of floor space. and used used a minimum of volume at a work station.

Another object of the present invention is to provide a new and improved parts magazine of the character described, which magazine eliminates the need for and reduces wasteful material-handling functions normally attributed to work operations of a similar type.

In the aforementioned U.S. patents, there are described and shown programmed article transfer apparatus having a movable transfer arm with fingers or jaws on the end of the arm for grasping, holding, moving, and releasing workpieces or parts. The magazine assembly of the present invention is adapted for use in cooperation with a programmed manipulator of this general type and is especially well suited for use in situations where a number of operations are to be performed on the same part at different work stations.

The foregoing and other objects and advantages of the present invention are accomplished in an illustrated embodiment which comprises a new and improved workpiece or article storage magazine for holding a batch of parts and sequentially aligning each part in the batch into a predetermined position and orientation for handling by a programmed transfer arm. The magazine includes a tray carrier means having a vertical support column, and a plurality of trays, each adapted to hold a large number of parts in predetermined orientation, are mounted in a vertical, stacked array on the column for vertical, relative movement thereon. Index means is provided for supporting the carrier and rotating the trays to sequentially align each oriented part in a tray into a preselected position where it may be grasped by the arm of the a manipulator which a has been programmed to receive a part in said preselected position and with said predetermined orientation. Carriage means is mounted for vertical movement on the column of the tray carrier and is engageable with at least one tray in each pair of vertically adjacent trays in the stacked array for sequentially increasing the vertical spacing of the trays in each adjacent pair to provide access therebetween so that the arm of the manipulator may be moved between the spaced trays and may grasp one of the oriented parts from one of the trays, remove the part and perform operations thereon, and then return the part to the tray and deposit it therein with the same orientation. The tray carrier, when fully loaded with trays full of parts, is readily movable from one location to another and, preferably, a separate index means is permanently positioned at each work station. After a work operation has been completed on each part in the batch of parts contained in a tray carrier, the loaded carn er is then moved by a forklift truck or other means to the next work station in the system and is set down on the index means positioned at the station for the next sequence of operations. The three dimensional orientation of each part is thus maintained so that the programmed manipulator at the new station may grasp each article and perform additional work operations on it without requiring an attendant to load, unload, or orient the articles at each station.

For a better understanding of the present invention, reference should be had to the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of a new and improved magazine assembly loaded with a batch of parts and shown in position at a work station wherein a programmed article transfer arm is provided:

FIG. 2 is a perspective view of an indexing mechanism of the magazine assembly in accordance with the invention;

HO. 3 is a perspective view of a tray carrier of the magazine assembly in accordance with the invention;

FIG. 4 is a vertical, cross-sectional view of the tray carrier taken substantially along line M of FIG. 3;

FIG. 5 is a perspective view of a single article-supporting tray, constructed in accordance with the invention adapted for use with the tray carrier of FIG. 3;

FIG. 6 is a cross-sectional view of the tray taken along line 6-6 of FlG. 5;

FIG. 7 is a fragmentary perspective view of a radial portion of a modified tray, constructed in accordance with the present invention and having especially shaped pockets or recesses therein for holding parts of different shapes in selected orientation;

FIG. 8 is a horizontal cross-sectional view through the center column structure of the tray carrier taken substantially along line 8-8 of FIG. 4;

FIG. 9 is a side elevational view of a carriage or crab mechanism mounted for vertical movement along the center column of the tray carrier for sequentially increasing the vertical space between each pair of adjacent trays mounted on the carrier; and

FIGS. 10 through 18 are frame fragmentary, vertical, sectional views taken substantially along line 1040 of FIG. 8 illustrating a sequence of different operating positions of the crab mechanism as it is moved along the column of the tray carrier.

Referring now, more particularly, to the drawings, in FIG. 1 therein is illustrated a new and improved magazine assembly in accordance with the present invention an generally referred to be the reference numeral 20. The magazine assembly 20 is adapted to hold a batch or limited quantity of

parts

22, 22A, 22B (FIGS. 1 and 7) and to sequentially position each individual part in the batch into a predetermined location and with a predetermined orientation relative to a work station at which is located apparatus on which a work operation on the parts is to be performed. Each part in the magazine 20 is grasped by the transfer arm of a programmed article-handling device or manipulator, which may be of the type described in any one of the above identified patents, and is removed from the magazine 20, presented to the work apparatus so that the desired operations may be performed thereon, and is then removed from the apparatus and returned to the magazine 20 by the manipulator arm in the same orientation as it was grasped. The programmed article-handling device or manipulator is preferably of the type having a programmable storage drum or other storage element in which may be stored a large number of desired sequential positions of the transfer arm of the manipulator in the various axes of movement thereof. The manipulator will sequentially move the transfer arm to a predetermined series of positions and with predetermined orientation in each position. The manipulator can also be pro grammed to seize and release articles at any desired position. Furthermore, the manipulator can be programmed to produce an external operate signal each time the transfer arm has completed its series of programmed movements. This signal is supplied to the magazine assembly 20 and controls the sequential orientation of parts stored within the magazine to the article-grasping position of the transfer arm, as will be described in more detail hereinafter. Programmed manipulatois of this general type are described, for example, in the above-identified patents. The work transfer arm of the manipulator apparatus includes a pair of movable pickup jaws or fingers 24 for grasping and holding the parts 22, 22A, 2228, etc.. and the arm and jaws are movable in several different axes to pennit the part to be moved to and oriented in any desired position.

The magazine assemble 20 includes an indexing mechanism 26 (FlG. 2) which is normally bolted or permanently attached in a desired position at the work station, and the indexing mechanism is adapted to support a tray carrier 23 (FIGS. 3 and 4), on which tray carrier is mounted a plurality of annular part-supporting trays 30 (F I08. 1, 5, and 6) arranged in a vertically stacked, concentric array. Each tray 30 is adapted to contain a selected number of parts or workpieces 22, 22A, 228 etc., and when the carrier 28 is fully loaded with a stack of part-containing trays thereon, the loaded unit is bodily movable from one work station to another with a forklift. other lifting device, or by hand. in H6. 1, the tongue portions of a forklift vehicle are shown and indicated by the numerals 32, and the tongues are movable into a lifting position beneath the base of the tray carrier 28 for moving it from one indexing mechanism 26 to the next. More particularly, the movable tray carrier 28 includes a circular base 34. preferably formed of strong material, such as metal, and the base includes a lower flange 36 provided with an-indexing mark 37 and having several circumferentially spaced-apart rubber feet 38 mounted on the outer rim for supporting the tray carrier from the floor or other surface when the carrier is not mounted on an indexing mechanism 26. The base 34 includes a cylindrical hollow body 39 and an upper flange 40 for contact with a lifting mechanism, such as the tongues 32 of a forklift vehicle (FIG. 1) used for transporting the loaded tray carrier from one place to another.

A vertical, centrally positioned, tray support column 42 extends upwardly from a horizontal circular wall 41 at the center of the base 34 and a stack of trays 301, 302, 30-3, etc. (FIG. 1) are removably mounted on the upstanding column 42. The circular wall 41 and lower flange 36 are connected by a frustoconically shaped wall 43 which forms a recess 56 for engagement with the indexing mechanism 26, as will be described more fully hereinafter.

The indexing mechanism 26 includes a housing or enclosure 44 having a horizontal top wall 44a, a peripheral skirt or sidewall 44b, and a plurality of mounting feed 46'extend outwardly from the skirt, each foot being provided with an aperture therein to receive fastening means, such as a bolt or lag screw 48, for fixedly securing the mechanism to the floor or other surface in a desired position relative to a production machine, or the like, at a work station..

The indexing mechanism '26 is supplied with hydraulic power through a pair of hydraulic lines 50, one for hydraulic pressure in and one for return to sump, these lines being interconnected with the hydraulic system of the programmed manipulator with which the magazine assembly 20 is to be associated. Similarly, electric power for operating the indexing mechanism 26 is supplied through a cable 52 and external operate control signals from I the associated programmed manipulator are supplied to the indexing mechanism 26 over a cable 52a. The external operate signal supplied by the associated manipulator may comprise either a continuous relay generated signal or a pulse-type signal, depending upon the internal circuitry of the manipulator, as will be readily understood by those skilled in the art. Both types of signals are available in manipulators commercially available at the present time. it will be understood that the associated manipulator may be programmed to generate an extemal'operate signal at any desired time as required by the arrangement of parts on the trays 30. For example, if only one annular series of parts are positioned on a tray 30,.the manipulatorwill develop an external operate signal after each cycle of movements associated with one part. On the other hand, if several parts are located along or near a radius extending outwardly from the center of the tray, the manipulator may be programmed to operate on all parts along this radius before it generates an external operate signal.

The indexing mechanism 26 includes a suitable electricaL' geared brake motor which drives a frustoconical drum 54 mounted above the top wall 440 of the housing 44. The drum 54 is adapted to drivingly engage a tray carrier 28 and is adapted to seat in the similarly shaped recess 56 formed in the base 34 of the tray carrier. Accordingly, when the drive motor 1 is energized it drives the drum 54 which in turn rotates the tray carrier and the drive motor is controlled by any suitableu' means, such, for example, as a series of cams associated with the drum 54, so that the drum 54 is rotated through a.

predetermined are or angle in response to each external;

operate signal supplied from the associated manipulator, this.

predetermined angle being correlated with the spacing of the parts in the trays 30 so that each part is sequentially moved to the programmed part-grasping position of the fingers 24 of the manipulator with the correct orientation to be grasped thereby.

In order to initially align a loaded tray carrier 28, which is placed on the indexing mechanism 26, the mechanism includes a marker projection 260 formed on the housing, which cooperates with the marker 37 on the tray carrier base 34 (FIG. 3) to provide a means for precise orientation of the trays 30 with respect to the associated manipulator. A manual con trol lever 260 is employed to energize the driving motor for the drum 54 independently of the programmed control thereof by the associate manipulator. Accordingly, after the tray carrier 28 is seated on the drum 54, lever 26c is moved to rotate the carrier 28 until the

markers

26a and 37 are aligned.

When a loaded tray carrier 28 is centered above the axis of rotation of drum 54 and then lowered in place thereon, the drum provides vertical support for the loaded carrier and stack of trays 30l, 30-2, 30-3, etc. mounted thereon and, additionally, is operable to rotate the tray carrier about its central vertical axis in a precise manner to sequentially align each part 22, 22A, 228, etc., carried in the trays to a pickup position on a selected radial plane ready for pickup by the jaws of fingers 24 of the transfer arm. Because the engaging frustoconical surfaces of the drum 54 and the tray carrier base 34 are relatively large, an excellent drive coupling is obtained with no slippage occurring even though the loaded carrier is held in place on the drum only by the force of gravity.

Each tray 30 includes an outer, shallow, frustoconically shaped, annular ring portion 58 (FIGS. 1, 5, 6, and 7) preferably formed of integrally molded, high-strength, impactresistant plastic material, with a plurality if indentations or pockets 58a (FIG. 5) therein, one for each part to be carried. In the case of a symmetrical article such as the generally cylindrical parts or articles 22 shown in FIG. 1, the pockets or indentations 58a are slightly frustoconical in shape in order to readily accommodate the vertical insertion and withdrawal of the parts or articles from the pockets in the trays by the fingers 24. Furthermore, the pockets or indentations 58a are shaped so that the part is held with the proper orientation so that it can be readily grasped by the fingers 24 of the associated programmed manipulator.

FIG. 7 illustrates a modified tray construction 30A wherein the outer ring portion 58A of the tray is formed with nonsymmetrical, specially shaped pockets 59 which are suitable for holding a pair or more of differently shaped articles, such as the different parts 22A and 22B.' For this purpose, the pocket 59 includes a relatively deep groove 59A for the part 22A and a deep groove 598 at right angles thereto for part 22B, and a shallow indentation 59C is provided to accommodate the horizontal flange portion on the part22B. Thus a single tray can be utilized for holding several differently shaped parts with the correct orientation on the tray for seizure by the fingers 24, by proper design of the part-receiving pockets in the tray. When possible, the annular ring portion 58 of the trays are with upwardly projecting shaped indentations or pockets in the lower surfaces thereof in order to accommodate and fit over the upper portions of the pans or articles contained in the next lower tray in the stack. Thus, when a stack of trays is fully loaded with articles or parts in each tray, the parts themselves interlock the trays together in a nested fashion with each pair of vertically adjacent trays in the stack requiring a minimum vertical spacing therebetween to form a neat, compact bundle of minimum volume which is easy to handle bodily as a unit on the tray carrier 28. Moreover, the parts or articles 22 are securely held in place by and between each pair of adjacent vertical stacked trays in the array or stack on the carrier. The diameter of the annular

outer rings

58 or 58A of the trays, the thickness of the material, and the shape of the article-receiving

pockets

58a or 59 are determined by the type, number, weight, size, and shape of articles 22, 22A, 228, etc., which are to be carried in the trays and, depending upon these factors, the angular and radial spacing of the pockets in the trays is determined.

In order that the indexing mechanism 26 may accommodate trays having different outer diameters and holding different numbers of parts, in the index mechanism is provided with a selector switch 26h, which is adjustable to correspond with the number of articles carried in each tray, and the switch 26b is used to set up the desired amount of angular rotation of the drum 54 between the sequential handling of successive parts in the tray by the fingers 24 of the associated manipulator. In the event the parts are arranged in a plurality of circles of different radii, as shown in FIG. 5, the parts in the innermost circle are preferably higher than those in the middle circle. and those in the middle circle are higher than those in the outer circle. This is readily accomplished by the shallow frustoconical shape of the outer ring member (FIG. 6). Each time the indexing mechanism 26 received an external operate signal from the associated manipulator, the drum 54 rotates a precise angular amount equal to the angular distance between the succeeding parts to be handled. When the tray carrier 28 is loaded with a stack of trays 30, each having a given number of parts therein, the switch 261) on the index mechanism 26 is set to the given number and the index mechanism provides the proper degree of rotation of the tray carrier each time a succeeding part or workpiece 22 is handled by the jaws 24 of the transfer arm. The frustoconical shape of the tray member 58 permits a pair or more of article-containing

pockets

58a or 59 to be positioned on a common radial extending from the center of the tray and, accordingly, two or more parts positioned in radially spaced pockets on the common radial can be readily picked up and replaced by the jaws 24 without interference, because of the difference in height or level between the pockets closer to the center and the pockets outboard thereof. As the

parts

22, 22A, 22B, etc. in the

trays

30, 30A, are picked up and replaced the pockets after a work operation has been cm completed on the part, the arm and jaws of or fingers 24 are moved radially toward and away from the column 42 between pairs of adjacent vertical'trays in the stack. The jaws 24 open and close to grasp and release the articles, and the manipulator arm is movable in a vertical direction so that all of the articles in the stack of trays on the column can be handled in sequencev After the processing of each part or all of the parts on a common radial has been completed, the stack of trays is rotated a precise angular amount to align the next part or common radial into position on the same plane as the predetermined path or plane of horizontal and vertical movement of the arm and jaws 24.

The outer diameter of the

ring member

58, 58A of the

trays

30, 30A, and the size, shape, location, and number of pockets therein, depends upon the size, shape, and weight of the parts or workpieces 22, 22A, 228, etc., which are to be carried on the trays and, as previously stated, preferably the tray rings are fabricated of integrally molded, high-strength, impact-resistant, plastic material.

Each tray is supported for vertical movement on the center column 42 of the tray carrier 28 and is keyed thereon against relative rotation and for this purpose each tray includes a centrally disposed pair of upper and

lowerhub members

60 and 62, respectively, preferably formed of lightweight, strong material, such as aluminum or thin sheet steel. The upper and lower hubs are fastened together with bolts 64, and the

tray ring

58, 58A is sandwiched between the hubs (FIG. 6). The hubs are provided with aligned, generally triangularly shaped

openings

60a and 62a, respectively, in order to accommodate the general cross-sectional shape of the vertical column 42 of the tray carrier 28. Each hub member is formed with a plurality of circumferentially spaced,

vertical fingers

60b and 62b, respectively, and each pair of

fingers

60b and 62b in vertical alignment support a separate tray guide block 66. Each tray includes three equilaterally spaced guide blocks and the blocks serve as spacers between vertical adjacent trays in the stack. In addition, the guide blocks function to key the trays the structure of column 42 and to guide the vertical sliding movements of the trays in the stack.

Each guide block 66 includes a horizontal groove 66a on the inner face spaced about midway between the upper and lower end for use in lifting or elevation of the trays on the column, and each trio of blocks on a tray is adapted to slide freely within a trio of equilaterally spaced, outwardly facing ways or tracks 70 (FIG. 8), formed between adjacent facing wall portions 72a of channel-shaped, vertical column members 72. As best shown in FIG. 8, each column 72 includes a pair of outer edge stiffening flanges 72b normal to the adjacent wall portions 720 and a single web portion 72c extends between the wall portions 720. The web forms a portion or sidewall for the column on a side directly opposite each guideway or track 70. The columns 72 are connected to and supported at their lower end on the center wall 41 of the base 34 and the columns are held in upright parallel-spaced relation, as shown in FIG. 8, to form the generally triangular crosssectional shaped vertical column structure 42.

The trio of guide blocks 66 on each tray 30 are slidable in the vertical ways 70 formed by the facing pairs of column wall portions 72a, and the trays are thus keyed by the guide blocks against relative rotation on the column structure. The channels 72 are connected at the upper end and are held at the desired spacing by an upper spacer 74 (FIG. 3), and a similarly shaped spacer 76 (FIG. 4) is provided adjacent the lower end of the column above the base wall 41.

Resilient cushions

78 and 80 are mounted above and below the lower sp ricer 76, and beneath the cushion 80 is provided a trio of spacer blocks 82, each having its opposite ends fastened to the wall portion 72a of the columns. The blocks 82 are connected to the center wall 41 of the base 34 by bolts 84 and thus the column structure 42 is removably attached to the base 34 of the tray carrier 28.

The trio of columns 72 are attached to the upper spacer 74 and the spacing leg members 82 by suitable fastening means, such as cap leg or rivets (not shown) and the resulting hollow column structure 42 is relatively light and strong and readily adapted to support a vertical stack of trays 30-1, 30-2, 30- -3, etc. The trays are adapted to slide freely on the column 42 while in vertically stacked relation thereon with the column structure extending upwardly through the triangular-shaped openings provided in the

center members

60 and 62 of each tray.

Referring to FIG. 1, the upper tray 30-13 in the stack is spaced below the upper end of the column 42 and when the programmed transfer arm and jaws 24 begin to function to load and unload the parts from the trays, the spacing between one pair of trays in the stack is increased, beginning with the bottom pair of trays 30-1 and 30-2 and proceeding up wardly in sequence until only the parts in the upper tray 30- 13 remain to be handled by the arm. The vertical spacing between each pair of vertically adjacent trays in the stack is normally maintained by end-to-end engagement of the guide blocks 66 on the respective trays in the pair, and when an increase in spacing to provide access by the transfer arm is provided, the upper tray of the pair and all of the trays in the stack thereabove are lifted upwardly on the column 42.

In accordance with the present invention, a tray carrier 28 with a full stack of trays thereon and each tray fully loaded with parts or workpieces is placed in position on an indexing mechanism 26 at a work station adjacent the pickup jaw or fingers 24 of a programmed transfer arm. The arm is programmed to grasp each part 22 and move the part from the tray carrier 2% of the magazine to a work station where a work operation is to be performed. After the work operation has been completed, the part is again grasped by the arm and is returned to its original position or pocket in a tray, and the process is repeated in sequence for every part contained in the magazine. Access to the parts in the lowest tray 30-1 in the stack is provided by lifting upwardly the lowest tray 30-2 and all those trays 30-3 through 30-13 in the stack thereabove and when ample spacing between the trays 30-1 and 30-2 is obtained the transfer arm and jaws 24 can move radially inwardly and outwardly between the spaced-apart trays to handle the individual parts in the tray 30-1. When all of the parts 22 in the tray 30-1 have been processed and returned to their original pockets in the tray, the spacing between the tray 30- -1 and 30-2 is returned back to normal by lowering tray 30 -2 and the rest of the trays in the stack thereabove. Tray 30- 3 and trays 30-4 through 30-13 in the stack are then lifted to provide access to the parts in the tray 30-2. This sequence is repeated for each tray in the stack until the uppermost tray 30-13 is reached. The transfer arm of the as sociated manipulator is likewise programmed to grasp a part at a particular level corresponding to the tray which is then being made accessible to the arm.

In order to sequentially increase the vertical spacing between pairs of vertically adjacent trays in the stack on the tray carrier, a crab or carriage mechanism 90 (FIGS. 8 and 9) is mounted for sliding vertical movement within the column structure 42. Referring to FIG. 8, the crab mechanism 90 is Y- shaped in plan view and includes a trio of leg assemblies 92 which project radially outwardly in equilaterally spaced array relative to the vertical center axis of the column. Eachleg assembly of the crab is adapted to slide between a pair of facing wall portions 72a of a pair of adjacent column member 72, and the outer end portions of the leg assemblies are guided between the facing wall portions which define the ways or tracks 70 by guide buttons 96. The trio of leg assemblies 92 of the crab 90 are all identical and, accordingly, only one will be described and referred to in FIGS. 10 through 18 of the drawings. The crab mechanism 90 is slidable vertically within the column structure 42 on a centrally disposed, vertical drive rod 94, which rod is also reciprocal in a vertical direction within the framework of the column structure. The rod 94 is reciproeated to actuate crab mechanism 90 to move in increments from a lower or rest position (FIG. 4) adjacent the cushion member 78 to a highest or uppermost position (FIG. 18) at the top of the column adjacent the upper spacer 74. When the crab reaches the uppermost position, it is released for free fall downwardly in the column structure to return to the lower or rest position of FIG. 4 ready to repeat the next tray-lifting sequence. The

cushion members

78 and 80 absorb the shock of the falling crab and in addition the cushion members and spacer 76 being mounted on the lower end of the drive rod 94 act to initially lift the crab from its rcst position to the next higher lifting position to increase the spacing between trays 30-1 and 30-2 to provide access for the arm to handle the parts in the lowest tray 30-1.

The crab mechanism 90 is formed with a circular aperture or bore 90a at the center in order to accommodate the drive rod 94, and each of the leg assemblies 92 is provided with an enlarged downwardly facing slot or recess 92a in communication with the center bore. The slots 92a are open at the bottom and each is defined by a pair of opposite vertical sidewalls 98 joined by a top wall 99. Within each slot is mounted a lifting mechanism 100 for engaging the drive rod 94 and the guide blocks 66 of the trays for lifting the trays in the stack on the column 42 as described.

Each lifting mechanism 100 includes an outer, tray-engaging pawl 102 pivotally mounted on a pin 104, an inner rod-engaging pawl 106 pivotally mounted on a pin 198, an upper generally U-shaped latch member 110 pivotally mounted on a pin 112 and a T-shaped key member 114 disposed for relative vertical sliding movement on the pin 112 which projects through an elongated slot 114a formed in the head of the key member. The tray-lifting pawl 102 includes an outwardly projecting foot or toe portion 102a at the lower end, movable into and out of engagement with the horizontal grooves 66a on the inside faces of the guide blocks 66 of the trays 30, and the drive rod pawl member 106 includes an inwardly projecting foot or toe portion 106a at the lower end movable into and out of vertically spaced-apart, horizontal grooves 94a formed on the drive rod 94 at intervals equal to the normal spacing between adjacent trays. At each level a trio of grooves 94a are spaced equilaterally around the cylindrical outer surface of the drive rod to face the trio of leg assemblies 92 of the crab mechanism 90. The drive rod 94 is reciprocal vertically within the column structure 42 and is movable between a lower position (FIG. 4) wherein the lower end of the drive rod 94 extends through an apertured 41a and is flush with the bottom surface of the center wall 41 of the tray carrier base 34 and an upper position wherein the lower end of the drive rod is raised by an amount determined by the normal vertical spacing between the trays in the stack. The rod 94 is movable up and down at the desired time by means of a hydraulic piston 101 (FIG. 2) mounted in the indexing mechanism 26 and in coaxial alignment with the drum S4. The piston 101 is movable from a first or lower position wherein the upper end surface 1010 is flush with the upper surface 54a of the drum to an upper position as depicted in dotted lines (FIG. 2) wherein the upper end surface is elevated by an amount determined by the normal vertical spacing between adjacent trays in the stack. Reciprocal movement of the piston 101 is in synchronism with the rotation of the drive drum 54 and is initiated by timely application and evacuation of hydraulic fluid supplied through the hydraulic line 50 to the underside of the piston.

When a loaded tray carrier'28 is placed on the drum 54 of the indexing mechanism 26, the upper end surface 101a of the piston 101 is in direct contact with the lower end of the drive rod 94.. After the stack of trays has been initially indexed, as previously described, and the selector 26b has been set to cor respond to the number of angular positions in which the trays 30 are to be positioned, hydraulic fluid is supplied to the lower end of the piston 101 which moves upwardly a selected amount causing a corresponding upward movement of the drive rod 94 in the column structure 42 of the tray carrier 28. When hydraulic fluid is evacuated from the lower end of the piston 101, the piston and drive rod are returned downwardly to the original lower or rest position (FIG. 4).

Referring to FIGS. through 18, the tray lift pawl 102 is biased in a clockwise direction about the pin 104 by a leaftype bias spring 116, the inner end of which engages the outside of the lower shank portion of the T-shaped key member 114 and the outer end of the spring engages a groove 103 on the inside surface of the pawl below the mounting pin. The drive rod pawl 106 is biased in a counterclockwise direction about the pin 108 by a similar leaf-type bias spring 118, the inner end of which is engaged against the inside of the lower shank portion of the T-shaped key member 114 and the outer end of the spring is seated in a groove 105 on the inside surface of the pawl 106 below the pin 108. Accordingly, the lower end portions of both

pawls

102 and 106 are biased outwardly from the ends of the slot 920 in opposite directions and the foot projects projections 102a and 106arespectively, are urged outwardly into engagement in the grooves 66a of the guide blocks 66 on the trays 30 and the grooves 94a in the drive rod 94, respectively.

Each

pawl

102 and 106 is formed of three thin sheet members laminated together and having a central lamina with an enlarged, upwardly projecting finger. The enlarged upper finger on the tray lift pawl 102 is designated as 102b and the enlarged upper finger on the drive rod pawl 106 is designated as 106k. The outside pair of laminas of the

respective pawls

102 and 106 are shaped differently from their respective center or middle lamina and, as best shown in FIG. 10, each outside lamina of the pawl 102 includes a pair of short, spaced-apart, upwardly projecting lugs 1112c and 102d, which lugs form the end walls of an upwardly facing slot or groove 107 for receiving the lower end of the left-hand leg 1 10a of the U-shaped latch member 110. The outside laminas on the drive rod engaging pawl 106 are a shaped differently from the center or middle lamina thereof and are formed with a pair of short, spaced-apart, upwardly projecting lugs 106C and 106d which define the end walls of an upwardly facing recess 109 for receiving the lower end of the right-hand leg of a downwardly extending U-shaped spring member 120 mounted on the latch member 110 below the pin 112 between the lefthand and right-hand legs 110a and 110b. In addition to the depending legs 110 a and 110b, the latch member 110 is formed with a toothlike projection 110 c on the Iefthand upper comer, which tooth is adapted to engage a downwardly depending vertical leg 1220 of an L-shaped, leaf-type biasing spring 122. The bias spring 122 includes a horizontal leg 122!) seated against the lower surface of the top wall 99 of the crab mechanism leg 92. The top wall 99 is formed with an aperture or bore 99a arranged in coaxial alignment with the longitudinal vertical center axis of the shank of the T-Shaped key member 114. The horizontal leg 122b of the L-shaped spring 122 is formed with an opening 123 therein in line with the opening 99a in the wall 99, and the downwardly depending leg 1220 of the spring is provided with an opening 124 adapted to receive the tooth projection 1100 on the U-shaped latch member 110, as best shown in FIG. 15.

Referring specifically to FIG. 10, in this view the tray-lifting mechanism 100 is illustrated during a free-falling condition as it falls downwardly at the end of a cycle from the upper end of the column 42 toward the resilient cushion member 78 on the lower spacer 76. The T-shaped key member 114 is in a lower or downward position on the lift mechanism and the pin 112 is at the upper end of the slot 114a in the head portion. In this position, the head portion of the key member is wedged directly between the upwardly projecting fingers 102!) and 106b of the tray lift pawl 102 and drive rod engaging pawl 106, respectively. When the head of the key member is wedged between the fingers 10217 and 10612, the

foot projections

102a and 106a of the respective pawl members are retracted inwardly from the opposite ends of the slot 920 and no longer engage the spacer block grooves 66a and the drive .rod grooves 94a. When this occurs, the crab mechanism 90 is then free to fall downwardly on the rod 94 within the column structure 42 without interference until the crab strikes the resilient cushion 78 on the lower spacer 76.

When the crab 90 contacts the cushion 78, the T-shaped key member 114 is forced upwardly from its lower position occupied during the free fall to an upper position wherein the pin 112 is at the bottom end of the slot 1140. In this position, the head of the key member 114 is no longer wedged between the fingers 102b and 10612 of the respective pawl members (FIG. 11) and the bias springs 116 and 118 act on the

pawls

102 and 106 urging the

foot projections

102a and 1060 outwardly. As shown in FIG. 11 the foot projection 106a extends outwardly into engagement in the first or lowest level groove 94a in the drive rod 94 but the foot projection 1020 is spaced below the groove 66a in the guide block on the second tray 302 in the stack. When pressurized hydraulic fluid is supplied to the lower end of the piston 101 in the indexing mechanism 26, the drive rod 94 begins rising upwardly toward the position shown in FIG. 12, lifting the crab 90 upwardly because of the engagement between the pawl 106 and groove 94a in the drive rod 94, and when the foot projection 102a of the tray lift pawl 102 has been lifted enough to be level or even with the groove 66a in the guide block on the second tray 30- -2 in the stack, the bias spring 116 is then effective to seat the foot projection 1020 in the groove. With the

foot projections

102a and 106a both seated in the

grooves

66a and 94a (FIG. 12), further upward travel of the rod 94 toward the positions of FIGS. 13 and 14 results in lifting of the tray 30-2 plus all of the trays 303 through 30-13 in the stack. The amount of uplift depends on the length of stroke of the piston 101 in the index mechanism 26 which is set up to provide the clearance or access space S (FIG. 14) which is needed between adjacent pairs of trays in the stack for handling of the parts 22 by the transfer arm jaws or fingers 24.

During the lifting operation FIGS. 12, 13 and 14), the U- shaped spring 120 is operable to bias the U-shaped latch member in a clockwise direction on the pin 112 and the left-hand leg 110aof the latch moves into the recess 107 between the

lugs

102c and 102d on the pawl 102. When this occurs, the lower end of the leg 110a is in locking contact against the lug 102d and the pawl 102 is locked against rotation and is capable of supporting a relatively heavy load including the entire stack of loaded trays 302 through 30-- 13 which are mounted on the tray carrier, When the drive rod 94 reaches an upper position at the erid of the upward stroke of the piston I01, as shown in FIG. 14, full or maximum separation S between the trays 30-1 and 30-2 in the stack is achieved, and this increased spacing permits ready access to the parts 22 in the lower tray 30-1 by the programmed transfer apparatus and jaws or fingers 24 thereof.

During a lifting operation on the tray 30-2 in the stack, the drive rod engaging pawls 106 of the crab mechanism 90 are locked in engagement within the lowest set of grooves 94a on the drive rod and rotation of the pawls on the pin 108 is prevented by engagement of the right-hand legs 11012 of the latch members I and the right-hand legs of the U-shaped latch springs 120 on opposite sides of the lugs 106C (FIGS. 12, I3 and I4).

Continued hydraulic pressure on the piston 10R maintains the expanded spacing S between the trays 30-1 and 30-2 while the parts 22 in the lower tray 30-1 are being processed and after the programmed transfer arm has completed the processing of all of the parts 22, the hydraulic pressure beneath the piston 101 is reduced and the fluid is permitted to drain out so that the drive rod 94 and piston return on a downward stroke toward the original starting positions (FIG. 25). As this occurs, the stack of trays including trays 30-2 through 30-13 is lowered on the column 42 and the vertical spacing S between the trays 30-1 and 30-2 is returned to a ncimal or minimum 'value. During the lowering operation time, the foot projections 102a on the lift pawls 01 102 are continuously maintained in engagement with grooves 66a in the guide blocks 66 on the tray 30-2. When the guide blocks 66 on the trays 30-1 and 30-2 are again in end-to-end contact, as shown in FIG. 15, the stack of trays 30-2 through 30- -13 is no longer supported by the crab 90 but instead is supported by the guide blocks 66 of the lowest tray 30-1. Upon further downward movement of the guide of the drive rod 94, the crab 90 becomes supported by the guide blocks 66 on the tray 30-2 instead of vice versa and the drive rod pawls 106 pivot in a clockwise direction from the position of FIG. 14 to that of FIG. 15. As this occurs, the U-shaped latch member 110 is pivoted in a counterclockwise direction because of the engagement of the lug 1106c between the right-hand leg 11% of the U-shaped latch member and the right-hand leg of the spring 120. The left-hand leg 11011 of the latch member is moved out of engagement with the lug 102d unlatching the pawl 102; however, the weight of the crab mechanism 00 and the spring 116 are sufficient to maintain engagement of the foot projection 1020 in the groove 66a of the guide block 66 on the tray 30-2. Accordingly, the crab mechanism 90 is retained at the level of the tray 30-2 and does not return to its original starting point or lowest level as does the drive rod 94 which continues downwardly as shown in FIG. 15. With the crab mechanism 90 thus retained at the level of the tray 30- -2, when the drive rod 04 is returned to its initial or lowest level, the second level of grooves 04a on the drive rod are in horizontal alignment with the foot projection 106a on the drive rod pawls I06, and the pawls are pivoted in a counterclockwise direction by the bias springs 118 until the projections 1060 are moved outwardly into engagement with the second level of grooves 94a on the drive rod.

On the next cycle of operation, the rod 9d begins an upward stroke and carries the crab mechanism 90 upwardly (FIG. 16) from the level of the second tray 30-2 to the level of the tray 30-3. Because of the leg M011 is no longer latching the pawl 102, the pawl is pivoted from the position of FM]. 15 to that of FIG. 16 as the upward stroke of the drive rod M proceeds. When the foot projections 102a of the pawl 102 are elevated enough to align horizontally with the grooves 66a in the guide blocks of the tray 30-3 at the next level, the springs 116 bias the pawls 102 in a clockwise direction to establish lifting engagement (FIG. 12) between the foot projections 102a and the tray 30-3. As the drive rod 94 continues on the upward stroke (FIGS. 13 and 14) the tray 30 -3 and the stack of trays 30-4 through 30-13 thereabove are lifted until the end of the upward stroke of the rod 06. At the end of the upward stroke, the vertical spacing S between the trays 30-2 and 30- -3 is attained and access to the parts 22 in the tray 30-2 by the programmed transfer arm and jaws 24 is provided,

The sequence of the operation just described and illustrated in FIGS. 10 through 16 is repeated in sequence for each higher level tray in the stack until the crab mechanism 90 reaches the highest or last tray 30-13. When this occurs, as shown in FIG. 17, and the drive rod )4 begins to rise on the next upward lifting stroke, the crab mechanism 90 is carried upwardly toward the top spacer member 74 (FIG. 18). Each leg of the upper spacer 74 is provided with an aperture 740 aligned with an aperture 990 in the top wall 99 of the respective legs 92 of the crab mechanism. A release pin 124 is mounted for vertical sliding movement in each aperture or bore 74a and is provided with a lockwasher 125 adjacent the upper end for preventing the pin from dropping downwardly from the spacer. Each pin is biased downwardly by a coiled compression spring 126 between the lower surface of the spacer 74 and a lower retaining washer 127 carried on a lower portion of the pin. As the crab mechanism 90 is moved upwardly from the position illustrated in FIG. 17 towards the position of FIG. 18, the release pins 124 begin to project downwardly into the bores 99a of the crab mechanism until the lower end of the pins contact the enlarged head portions of the respective T-shaped, key members 114 When this occurs, the head of each Tshaped key member is forced downwardly to a lower position, as shown in FIGS. 10 and 18, wherein the pin 112 is at the top of the slot 114a and the head is wedged directly between the upwardly extending fingers 1021; and 10617 on the center laminas of each pair of

pawls

102 and 106. When this condition occurs, the

lower foot projections

102a and 106a on the pawls are retracted inwardly so that no engagement with the grooves 66a in the guide blocks 66 or drive rod grooves 940 can occur. This retraction then permits the crab mechanism 90 to free a fall downwardly along the column structure 42 from the position at the top of the column (FIGS. 17 and 18) to the lower position, as shown in FIGS. 10 and 11, wherein the crab mechanism finally comes to rest on the resilient cushioning member 78. The cushion member 78 is supported on the lower spacer 76, which in turn in as attached to the drive rod 94 and the lower cushion member between the spacer 76 and spacing legs 82, helps to absorb the shock of the falling crab mechanism 90. With the crab mechanism in the lower position, as shown in FIGS. 4 and 11, the sequence of tray lifting is ready to be repeated, and usually the previous tray carrier 28 is then moved to another indexing mechanism 26 at another work station where a different work operation is to be performed on the parts 22.

The magazine assembly 20 described is capable of storing with predetermined orientation a batch of separate parts contained in a stack of trays mounted on a movable tray carrier. When a loaded tray carrier 28 is mounted on an indexing unit 26 and connected to the associated programmed workpiece transfer apparatus, the vertical spacing between each pair of vertical adjacent trays is increased above the normal spacing so that the transfer apparatus has access for movement between the trays for handling the parts or article 22 contained in the lower tray of the pair. After all of the parts have been processed, the spacing is returned to a normal value, and the spacing between the next pair of trays upwardly in the stack is increased and the cycle is repeated for each pair of trays in the whole stack. The loaded tray carrier 28 is readily movable to different indexing mechanism 26 or to storage locations, and because of the nested arrangement of the parts in the stacked trays, a relatively large number of parts can be contained in a minimum of space and are protected from outside damage.

While but a single embodiment of the present invention has been here specifically disclosed, it will be apparent that many variations may be made therein, all within the scope and spirit of the invention.

Iclaim:

l. A workpiece storage magazine for storing and sequentially positioning a plurality of individual workpieces adjacent a work station with predetermined orientation with respect thereto, comprising: tray carrier'means including a vertical support column. A plurality of trays for holding said workpieces in predetermined orientation, said trays positioned in a vertically stacked array on said column for relative vertical movement thereon, indexing means for supporting said carrier and rotating said trays to sequentially align successive workpieces thercin into a selected rotative position relative to said work station, and crab means mounted for vertical movement on said column engageable with at least one of a pair of adjacent trays in said stacked array for increasing the vertical spacing therebetween, thereby providing access between said spaced trays for pickup of said workpieces.

2. An article storage arrangement for transferring a number of articles between different work stations while maintaining a predetermined orientation of the articles with respect to said work stations, comprising: tray carrier means including a vertical support column, a plurality of trays for holding said articles in predetermined orientation, said trays positioned in vertieally stacked array on said column for relative vertical movement thereon, indexing means for supporting said carrier and rotating the same to sequentially align successive articles in said trays in a position for pickup, and carriage means mounted for vertical movement on said column engageable with at least one of a pair of adjacent trays in said stacked array for moving the same vertically away from the other tray of said pair, thereby providing access to the articles for pickup.

3, A workpiece storage and positioning device for holding a plurality of separate workpieces for pickup by a workpiece transfer arm, comprising a stack of workpiece-supporting trays arranged for vertical movement on a support column, each tray including means for holding a plurality of workpieces at circumferentially locations radially outward of said column, indexing means for rotating said trays to move successive workpieces into alignment with said transfer arm for pickup thereby, and means movable along said column for increasing the distance between pairs of adjacent trays in said stack to permit access to the workpieces contained on in one of said trays of said pair by said transfer arm.

4. A workpiece storage and positioning device for holding a plurality of separate workpieces for pickup by a workpiece transfer arm, comprising a plurality of workpiece-supporting trays arranged in moveable vertically stacked relation on a support column, each tray including means for holding a plurality of workpieces at circumferentially spaced locations radially outward of said column, indexing means for rotating said trays to move successive workpieces into alignment with said transfer arm for pickup thereby, and means movable along said column for pickup thereby, and means movable along said column for spreading pairs of adjacent trays apart to permit access to the workpieces contained in one of said trays of said pair by said transfer arm.

5. In combination, a plurality of article-supporting trays arranged in a stacked array on a vertical support column, pickup means movable toward and away from said column for sequentially engaging articles contained in said trays one at a time, means for rotating said stack of trays to align successive articles in the path of movement of said pickup means, and carriage means mounted on said column movable to engage at least one of said trays for increasing the spacing between said one tray and an adjacent tray in said stack, thereby permitting access to the articles in said adjacent tray by said pickup means extended between said one tray and said adjacent tray.

6. In combination, a plurality of article-supporting trays arranged in a stacked array on a vertical support column, pickup means movable toward and away from said column for sequentially removing articles contained in said trays, means for rotating said stack of trays to align successive articles in tray in said stack, thereby permitting access to the articles in said ad acent tray by said pickup means extended between said one tray and the adjacent trays.

Claims

1. A workpiece storage magazine for storing and sequentially positioning a plurality of individual workpieces adjacent a work station with predetermined orientation with respect thereto, comprising: tray carrier means including a vertical support column. A plurality of trays for holding said workpieces in predetermined orientation, said trays positioned in a vertically stacked array on said column for relative vertical movement thereon, indexing means for supporting said carrier and rotating said trays to sequentially align successive workpieces therein into a selected rotative position relative to said work station, and crab means mounted for vertical movement on said column engageable with at least one of a pair of adjacent trays in said stacked array for increasing the vertical spacing therebetween, thereby providing access between said spaced trays for pickup of said workpieces.

2. An article storage arrangement for transferring a number of articles between different work stations while maintaining a predetermined orientation of the articles with respect to said work stations, comprising: tray carrier means including a vertical support column, a plurality of trays for holding said articles in predetermined orientation, said trays positioned in vertically stacked array on said column for relative vertical movement thereon, indexing means for supporting said carrier and rotating the same to sequentially align successive articles in said trays in a position for pickup, and carriage means mounted for vertical movement on said column engageable with at least one of a pair of adjacent trays in said stacked array for moving the same vertically away from the other tray of said pair, thereby providing access to the articles for pickup. 3, A workpiece storage and positioning device for holding a plurality of separate workpieces for pickup by a workpiece transfer arm, comprising a stack of workpiece-supporting trays arranged for vertical movement on a support column, each tray including means for holding a plurality of workpieces at cIrcumferentially locations radially outward of said column, indexing means for rotating said trays to move successive workpieces into alignment with said transfer arm for pickup thereby, and means movable along said column for increasing the distance between pairs of adjacent trays in said stack to permit access to the workpieces contained on in one of said trays of said pair by said transfer arm.

6. In combination, a plurality of article-supporting trays arranged in a stacked array on a vertical support column, pickup means movable toward and away from said column for sequentially removing articles contained in said trays, means for rotating said stack of trays to align successive articles in the path of movement of said pickup means, and carriage means mounted on a said column movable to engage at least one of said trays for moving the same away from an adjacent tray in said stack, thereby permitting access to the articles in said adjacent tray by said pickup means extended between said one tray and the adjacent trays.