US3343690A

US3343690A - System for transporting sheet material

Info

Publication number: US3343690A
Application number: US527175A
Authority: US
Inventors: George A Dean
Original assignee: Dean Research Corp
Current assignee: Dean Research Corp
Priority date: 1966-02-14
Filing date: 1966-02-14
Publication date: 1967-09-26
Anticipated expiration: 1984-09-26
Also published as: BE699917A; FR1548318A

Description

Sept. 26, 1967 G. A. DEAN 3,343,690

SYSTEM FOR TRANSPORTING SHEET MATERIAL Filed Feb. 14, 1966 5 She9ts-$heet 1 Sept. 26, 1967 s. A. DEAN 3,343,590

SYSTEM FOR TRANSPORTING SHEET MATERIAL Filed Feb. 14, 1966 5 Sheets-Sheet 2'6 Z6 Z7 ,6 5/4/03 7 2/ ,7 5 7 i I :"EFf-li-ZFEEEEi-E 5 I I I I l J 35 1 1,1 l/VVf/V r04 25 35 650m; A. 0544/ Sept. 26, 1967 G. A. DEAN 3,343,690

SYSTEM FOR TRANSPORTING SHEET MATERIAL Filed Feb. 14, 1966 5 Sheets-Sheet 5 A rromvs y:

United States Patent 3,343,690 SYSTEM FOR TRAN SPGRTING SHEET MATERIAL George A. Dean, Overland Park, Kans., assignor to Dean Research Corporation, Kansas City, Mo., a corporation of Missouri Filed Feb. 14, 1966, Ser. No. 527,175 13 Claims. (Cl. 2146) The present invention is directed to a system for transporting articles, and more particularly to the accumulation and shifting of sheet material such as glass, paper, wood, cardboard, and others.

It is among the objects of the invention to provide a system which is simple in construction, efiicient in operation, is capable of rapid manipulation to stack and transport sheets, and which is adaptable for use with sheets of various sizes and for sheets of more than one size in a single stack.

In practicing the invention there is provided a head having a top and one or two sides. The head is hollow and is connected to a source of vacuum. The interior of the head has perforations and is adapted to hold a stack of sheets by the vacuum which supports the stack. Because the head is open at the bottom, sheets may be added thereto from below. Since the head is open on at least two sides, the sheets may be nested against closed sides regardless of the dimensions thereof and the applied vacuum will hold all of the sheets.

Various other elements are provided to complete the structure. In the head is a leveling plate contacting the top sheet and operated up or down by suitable means, such as a pneumatic ram to pick up and hold a stack of sheets. A support for the head is pivoted so that the stack may be transferred to a holding area or tractor or rack by tilting the head and releasing the vacuum. The assembly is usually mounted on an overhead track so that it may be moved to desired areas for operation.

In the accompanying drawings constituting a part hereof, in which like reference characters represent like parts, there are shown two embodiments of the invention. In said drawings:

FIG. 1 is a side elevational view of one embodiment of the invention showing the operation of adding a sheet to a stack already held in the head;

FIG. 1A is a side elevational view of a rack, buck or holder for a stack of sheets, illustrating the transfer thereof from the head;

FIG. 2 is a perspective view looking up from underneath the head of FIG. 1, showing the arrangement for holding the sheets;

FIG. 3 is an enlarged fragmentary cross-sectional view of one corner of the head illustrating the manner in which the vacuum holds the stack of sheets within the head;

FIG. 4 is a top plan view taken along line 44 of FIG. 1 showing the construction of the endless conveyor belt;

FIG. 5 is a side elevational view of the belt of FIG. 4 with means for lifting a sheet into the stack;

FIG. 6 is a modified form of the invention in which the stack of sheets is vertically placed; and

FIG. 7 is a view similar to FIG. 1A in which the rack or buck is formed to hold the stack shown in FIG. 6.

Referring to the drawings, on an overhead support 1 there is fixed a pair of spaced rails 2 and 3. A trolley 4 is held for movement on the rails by wheels 5 and 6. Hanger 7 depends from trolley 4 and has a pivot 8 to which is linked support 9. Means are provided for moving support 9 or holding it in adjusted position, such means being manual, mechanical, hydraulic or any other known means.

The head includes a top 10 and

sides

11 and 12 at right angles to each other and to top 10. The bottom and the other two sides of the box-like head are open.

Sides

11 and 12 are hollow having a cavity 13 therein adapted to be connected to a source of vacuum by duct 14. Within the head is leveling plate 15 which is fitted with actuator 16 which may be a hydraulic ram serving to raise and lower the stack of sheets. Ceiling 17 of plate 15 is perforated and covers hollow space 18 therein.

Sides

19 and 20 of the head are also perforated so that channels of communication may be established with cavity 13 of the head. The bottom of the head structure is open to permit entry of the sheets.

Means are provided to mask or cover

portions

21 and 22 which are above the top of leveling plate 15 in its several adjusted positions. Such means may be, for example, roller curtains mounted on plate 15 with the free ends fixed at the junction of head top 10 and the

sides

11 and 12 of the head. Seals 23 are provided in the sides of the head and cooperating level plate to prevent loss of vacuum. Such seals are usually of rubber or other elastic materials.

Referring to FIG. 1, an endless conveyor 25 for bringing sheets 26, say of glass, is located below the head and its associated elements, the conveyor passing around roller 27. Assuming that there is already a stack of sheets 28 being held by the vacuum in the head, and it is desired to add another sheet, the conveyor is stopped with sheet 26 directly below the stack. Actuator 16 is operated to lower the stack until it touches sheet 26 as best shown in FIG. 3. Said sheet takes position 26" making contact with seal 23. The suction of the vacuum in cavity 13 draws out the air from the edges 29 of the sheets and from between the stack and the sheet, thus holding it as part of the stack. By reason of covers 21 and 22 there is no loss of vacuum above the leveling plate.

In one method of operation of the invention and referring to FIG. 1, the head would move downward somewhat vertically such that the stack 28 would embrace sheet 26. Upon contact, actuator 16 would move the leveling plate 15 vertically to allow sheet 26 to assume the position of 26". In other words, the leveling plate must move upward to allow the new sheet 26' to be accumulated.

When the head has accumulated the correct number of sheets, the entire assembly moves along the track 2 and 3 until it clears the conveyor from which the material was accumulated. The head is then rotated as shown in FIG. 1A in the direction of arrow 32 and released onto the rack.

To discharge the stack, it is moved to a position adjacent to a rack as shown in FIG. 1A. The rack has a base 30 and a sloping side 31. The angle of slope is about 7. Support 9 is swung in the direction of arrow 32 until it is locate-d just above the rack, the vacuum is released and the stack falls onto the rack at the angle shown, without any danger of breakage of glass.

The cavity within the leveling plate is used to obtain the pressure differential across the stack from top to bottom necessary to lift the material. The cavity within the sides is used to act as a pump to exhaust the air film between sheets, such that the plates then become a somewhat homogenous mass. If the material being accumulated is glass in rather large sheets, it may be practical to score the sheets or plates, as shown at 33, to the smaller size just prior to accumulation. These large plates may then be accumulated and transported to a storage area and just prior to release, it the leveling plate is caused to deflect at the scoring points, the stacked large plates would break along the scored lines to produce the smaller plates.

In FIG. 5 is shown a mechanism for lifting a sheet into the leveling plate. It is particularly adapted for use where heavy loads are to be transported, such as ton lots of sheets, it is desirable to hold the head substantially stationary and lift the sheet up to the head. The endless conveyor belt has a pair of outside belts 35 (FIG. 4) and central spaced

belts

36 and 37. A table 38 is mounted on ram 39. It has a series of spaced parallel longitudinal ribs 43 adapted to be lifted into

spaces

40, 41 and 42 between the belts, by the action of ram 39. Such movement raises sheet 44 into contact with stack 28.

Glass 43 on the conveyor may be elevated to the accu- V mulated stack by a vertically actuated table mounted within the conveyor. This conveyor table is timed by controls to the leveling plate. The table or positioner 38 moves vertically, lifting the glass plate until it makes contact with the accumulated stack 28 and on contact, the leveling plate moves upward until the upper surfaces of plate 43 move into the pumping action of the cavity, once again locking it to the plate immediately above, and the cycle is now ready for the next plate moving along the conveyor.

The conveyor table or positioner 38 is equipped with positioning fingers and rolls to assure alignment of the plate just prior to its vertical motion to the accumulated stack. When the head assembly has accumulated the desired stack, it then moves horizontally by the tractor away from the conveyor to a depot or holding area.

The head assembly, having traveled away from the conveyor to the rack area, is simply rotated by hydraulics or other standard methods to the position shown on the rack. The cavity pressure is returned to atmospheric and the head then swings clear, leaving the stacked glass on the rack. The head assembly then returns to its position over the conveyor for further accumulation.

In FIG. 6 is shown a modified embodiment which is at present preferred, especially where heavy weights of sheets are to be transported. Conveyor 35, shown in FIG. 5, carried sheet 104 which is moved vertically upward towards the head. The vacuum pulled through opening 103 maintains a vacuum in cavity 13 through perforated wall 19, much in the same manner as FIG. 3. However, in place of the rubber seal, there is a second cavity in the form of a slit 101 running in the same manner as the seal did. A vacuum is pulled through duct 102 causing high flow of air to pass through the slit 101. The vacuum pressure in duct 102 is relatively low at this time. When sheet 104 is moved into the relative vicinity of slit 101 a negative pressure is created between sheet 104 and the sheet immediately above. This causes atmospheric pressure to flip sheet 104 upwards into place. When this happens, it immediately tends to block the slit 101 causing a high vacuum to occur in 102. This sudden increase in the vacuum pressure closes the electrical switch 106 causing the actuator 16, through hydraulic ram 16 or other known actuating means, to raise the leveling'plate 15, whereby sheet 104 will then move upward and be accumulated at the bottom of stack 105. As soon as sheet 104 moves upward beyond the slit 101, the vacuum pressure in 102 drops and the electrical switch 106 causes the actuator to stop until the next sheet flips into the accumulating cycle.

In FIG. 7 is shown a modified rack or buck in which the stack is in position where all the sheets are in alignment. Side 31 is slightly inclined and base 30 is at right angles thereto. This has certain advantages in subsequent handling of the sheets.

In some cases, it might be convenient to have a threesided and possibly a four-sided head. Also, in some cases,

a cavity along only one side in combination with the cavity within the plate is sufficient.

In reverse of the accumulation feature of the head assembly, the head can travel to the depot and pick up a full stack of material and return to its position over a conveyor. If the leveling plate is then set in vertical down- Ward motion, it Will release a plate at a time as the bottom plate is forced downward by the action of the leveling plate, thus breaking the pump effect between the .top surface of the bottom sheet and the accumulated stack. In other words, the head assembly would spit out each plate at a rate programmed to meet the operation at the other end of the conveyor.

What is claimed is:

1. Apparatus for transporting sheets comprising a support, a head secured to said support, said head having a recess for the reception of a stack of sheets, a leveling plate in said head adapted to contact the top of said top sheet, a cavity in said head connected to a source of vacuum, the edges of said sheets communicating with said cavity, said vacuum drawing air from between said sheets to maintain said sheets in a stack supported by the head, and means for raising a sheet into said head.

2. Transporting apparatus according to claim 1 in which said head has at least one depending side against which the edges of said sheets abut and in which said cavity is formed.

3. Transporting apparatus according to claim 1 in which said head has two adjacent angularly placed depending sides against which the edges of said sheets abut and in which said cavity is formed.

4. Transporting apparatus according to claim 1 in which said support is pivoted.

5. Transporting apparatus according to claim 1 in which said support is mounted for lateral movement.

6. Transporting apparatus according to claim 2 in which the plane of said side is at an angle other than a right angle to the plane of said sheets.

7. Transporting apparatus according to claim 2 in which an actuator in said head connected to said plate is adapted to move substantially vertically.

8. Transporting apparatus according to claim 2 in which a perforated sheet covers said cavity and against which the edges of said sheets abut.

9. Transporting apparatus according to claim 2 in which said raising means is a table with means for raising said table to lift a sheet into contact with the lowest sheet of said stack.

10. Transporting apparatus according to claim 9 in which a conveyor for said sheets comprises a plurality of spaced belts, said conveyor passing above said table, said table adapted to pass upwardly through the space between said belts to raise a sheet.

11. Transporting apparatus according to claim 9 in which a slit in said support below said stack constitutes a narrow passage connected to said vacuum, the free end of said slit being above a sheet to be stacked.

12. Transporting apparatus according to claim 11 in which the vacuum pressure in the duct for said vacuum is relatively low and the raising of said sheet to be stacked is adapted to block said slit.

13. Transporting apparatus according to claim 12 in which a switch operated by increase in vacuum pressure in said duct actuates the movement of said head.

References Cited UNITED STATES PATENTS 2,249,201 7/ 1941 Ferguson 214-1 2,716,497 8/1955 Wahl et al. 2141 2,920,916 1/1960 Pagdin 214-1 3,040,920 6/1962 Harris 214-1 3,118,554 1/1964 Brainard et a1. 2 94-65 FOREIGN PATENTS 882,378 10/1959 Great Britain.

GERALD M. FORLENZA, Primary Examiner.

I. E. OLDS, Assistant Examiner,