US3508806A - Positioning apparatus - Google Patents

Description

Apr l 2 1970 K. F. HALL 3,508,806

POS IT IONING APPARATUS Filed Feb. 1, 1968 2 Sheets-Sheet 1 INVENTOR ATTORNEYS April 28, 1970 K. F. HALL POSITIONING APPARATUS 2 Sheets-Sheet 2 Filed Feb. 1. 1968 IArvEMTaR KMZM?Z B) W flMM/W ATToA'NEYS United States Patent 3,508,806 POSITIONING APPARATUS Kenneth Frank Hall, Barnet, England, assignor to W. Watson & Sons Limited, Barnet, England, a British company Filed Feb. 1, 1968, Ser. No. 702,324 Claims priority, application Great Britain, Feb. 2, 1967, 5,045/ 67 Int. Cl. G02b 7/00, 21/24 US. Cl. 350-90 9 Claims ABSTRACT OF THE DISCLOSURE An adjustable jig has a fixed frame pivotally mounted on a table. A movable frame is connected to the nxeu frame by first leaf springs and an adjusting screw is provided to move the movable frame. Two spaced jaw members, having resilient gripping pads, are each connected to the movable frame by second leaf springs extending perpendicular to the first springs. Separate adjusting screws are provided for moving each jaw member perpendicular to the second springs so that a member held in the jig may be rotated to a limited extent as well as moved in two perpendicular directions.

The invention relates to positioning apparatus.

The invention provides positioning apparatus for holding and accurately locating a member in position which apparatus comprises two jaw members, means for urging the jaw members towards each other to grip the said member between them, first position adjusting means operable to effect movement of the jaw members and any member gripped between them in a first direction along a line joining the two jaw members and second and third position adjusting means operable to move the two jaw members respectively and separately in a second direction perpendicular to the said line, the said jaw members having abutment faces for abutting said member, adapted to permit limited rotation of the member when either the second or third position adjusting means is operated independently of the other.

Preferably the said abutment faces are made of resilient material, preferably in the form of a resilient pad secured to the body of each jaw member.

Preferably the apparatus includes a fixed frame device and a movable frame device connected to the fixed frame device by leaf spring means extending perpendicular to the said first direction, the first position adjusting means being arranged to operate on the movable frame device to deflect the leaf spring means to effect movement of the movable frame device in the first direction, and the jaw members being connected to the movable frame device for movement in the first direction with it.

Preferably the jaw members are each connected to the movable frame device by further leaf spring means extending perpendicular to said second direction, and the second and third position adjusting means are arranged to deflect said further leaf spring means to effect movement of the jaw members relative to the movable frame member in the second direction.

Preferably the position adjusting means each comprise a screw jack device.

Preferably the fixed frame device is pivotally mounted on a supporting table over which the said member may be moved by the positioning apparatus to the required position, whereby when the required position is reached and the jaw members released, the positioning apparatus may be moved about the pivotal mounting away from the member.

Preferably the table is slidably mounted on a track for limited movement between stops so that the alignment 3,508,806 Patented Apr. 28, 1970 of different parts of the member on the table may be examined from a stationary viewing position by moving the table from one stop to another.

A specific construction of an adjustable jig embodying the invention will now be described by way of example, and with reference to the accompanying drawings in which:

FIGURES l and 2 are different perspective views of the jig mounted on a microscope.

In this example, the positioning apparatus is in the form of a jig 11 which may be used to position accurately a rectangular photographic plate 12 on a rectangular frame 13 for use in a photographic step and repeat camera (not shown). The jig is used to produce a series of accurately positioned photographic master plates, so that these may be interchanged on the step and repeat camera with known accuracy. The method used to locate the frame 13 on the jig is identical with the location means provided on the step and repeat camera.

The jig 11 includes a fixed frame 14 comprising an elongated bar 15 having a downwardly projecting arm 16 at each end and a further horizontally projecting arm 17 at one end. The fixed frame 14 is pivotally mounted on a rectangular supporting table 18 by horizontal extending pivot pins 9 (only one shown) seated in holes provided in each of the arms 16. Secured to the fixed frame 14 is a movable frame 20 comprising an elongated bar 21, parallel to the bar 15, having horizontal arms 22a and b extending perpendicular to it at the ends. The movable frame 20 is secured to the fixed frame 14 by two leaf springs 23 extending between the bars 15 and 21. A first position adjusting device is provided having a control knob 24 mounted on a screw-threaded rod passing through a screw-threaded aperture in the arm 17 and abutting the end of elongated bar 21 of the movable frame. By rotating the knob 24 the screw-threaded rod moves the movable frame 20 in a first direction along the length of the bar 21, relative to the fixed frame 14, and deflects the leaf springs 23.

The arms 22a and b have jaw mounting members 25a and b respectively extending parallel to them and connected to them by two leaf springs 26a and 26b respectively, extending between the arms and the jaw mounting members. The jaw mounting members 2511 carries at one end a fixed jaw member 27 which is provided with a rubber abutment pad 28 for abutting the edge of the plate 12. The jaw mounting member 25b carries a jaw member 27b at one end but the jaw member 27b is provided with an adjustable plate 29 on the front face of which another abutment pad 28 (not shown) is provided. Plate 29 is of spring material and is secured to jaw member 27b by a screw 31 (FIGURE 2), engagement with the side of plate 12 being controlled by defiection due to a set screw 30 (FIGURE 1) meshed in a screw threaded hole in jaw member 27b and in contact with the rear face of plate 29. Accordingly, pads 28 may be slightly adjusted toward each other.

Second and third position adjusting devices are provided by push rods 33 and 34, each having at One end knurled head screws 35 and 36, respectively, and each bearing against an end of the jaw mounting members 25a and 25b, respectively, at their other ends. Each rod 33 and 34 is screw-threadedly engaged with an aperture in the bar 15 and passes through an elongated slot in the bar 21, thereby permitting movement of the bar 21 by adjustment of the knob 24. By simultaneous adjustment of the screws 35 and 36, the jaw mounting members 25a and b may be moved in a second direction, perpendicular to the length of the bars 15 and 21 by deflection of the leaf springs 26a and 26b. If the screws 35 and 36 are operated together, the plate 12 is moved bodily in the second direction. If, however, one of the screws and 36 operated separately, the resilience of the pads 28 allows the plate 12 to pivot in a horizontal plane about the pad 28 which is not moved.

By provision of the knob 24, and screws 35 and 36 the position of the plate 12 may be adjusted in twoperpendicular horizontal directions and the plate 12 may be rotated about a vertical axis to a limited extent. By provision of the leaf springs 23, 26a and 26b, the horizontal adjustments act as virtual slides and backlash error is eliminated owing to the resilience of the springs exerting a continuous biasing force on the adjusting screwthreaded rods when the springs are deformed.

A catch is provided to hold the jig 11 down in the horizontal position as shown in the drawings. This catch comprises a boss 38a with a tapped hole secured to the table 18 and a knurled head screw 38b which may engage the tapped hole.

The rectangular frame 13 on which the plate 12 is to be accurately positioned and secured, is releasably held in position on the table 18 against three pins by two positioning clips 39 secured to the table 18.

In order to ascertain visually when the plate 12 is correctly positioned on the frame 13, the plate 12 is provided with reference marks and the jig is mounted on a microscope to enable accurate observation of the reference marks, As the reference marks are provided at spaced positions across the plate 12, it is necessary to move the plate 12 relative to the microscope objective lens in order to change from viewing one mark to another. To enable this to be done, the table 18 is slidably mounted for movement in one direction (parallel to the bars 15 and 21) on a platform 40. Two short rods (not shown) fixed to the platform 40 engage a groove on the underside of the table 18 to guide the movement and a projecting block 42 fixed to the table 18 is arranged to abut one or other of two spaced stop members 43 (only one being shown) provided by the spindles of micrometers 44 and 45 fixed to the platform 40 at the limits of the extent of movement of the table 18 on the platform 40. The position of the two micrometer spindles 43 may be separately adjusted by the micrometers 44 and 45.

To allow similar horizontal movement of the table 18 in a perpendicular direction, the platform 40 is slidably mounted on a sub-table 46. Two facing grooves in the platform 40 and sub-table 46 respectively fit onto opposite sides of a guide rod 47 to guide the sliding movement of the platform 40, and thereby the table 18, along the rod 47. A projecting block 48 is secured to the platform 40 and is arranged to abut one or other of two stop members 49, provided by the spindles of micrometers 51 and 52 and fixed to the sub-table 46 at the limits of movement of the platform 40 on the subtable 46. The position of the micrometer spindles 49 and 50 may be adjusted by the micrometers 51 and 52 respectively. The sub-table 46 is fixed rigidly, although releasably, to the microscope frame.

In use, the four micrometers 44, 45, 51 and 52 are set at the required positions in accordance with known information regarding the position of the reference marks on the photographic plate 12. The control knob 24 and screws 35, and 36 are then adjusted so that the reference marks appear at the correct position in the field of view in the microscope when the table 18 is moved in succession against the various stops limiting its movement. The plate 12 may then be cemented to the frame 13, the jaws of the jig 11 released from the plate 12, the catch 38 released and the jig removed from the plate 12 by moving about its pivotal mounting to a vertical position. The frame 13 and plate 12 may then be lifted upwardly away from the clips 39.

The invention is not restricted to the details of the foregoing example.

I claim:

1. Positioning apparatus for holding and accurately locating a member in position, which apparatus comprises two jaws for gripping an object between them, a first frame device, a second frame device, first resilient connecting means connecting said second frame device to said first frame device so that said second frame device is movable in a first direction parallel to said first frame device, first position adjusting means for effecting movement of said second frame device in said first direction, second resilient connecting means connecting one of said jaws to said second frame device so that said one of said jaws is movable in a second direction perpendicular to said first direction, second position adjusting means for moving said one of said jaws in said second direction, third resilient connecting means connecting the other of said jaws to said second frame device so that said other jaw is movable in a third direction parallel to, but spaced from, said second direction, and third position adjusting means for moving said other jaw in said third direction, said first, second and third position adjusting means being operable separately and independently of one another.

2. Positioning apparatus as claimed in claim 1 in which each said jaw comprises a jaw member having a resilient pad secured on its inner face.

3. Positioning apparatus as claimed in claim 2 in which said first resilient conecting means comprises a first pair of spaced leaf springs extending perpendicular to the said first direction, and said second and third resilient connecting means each comprise second and third pairs of spaced leaf springs, respectively, extending perpendicular to said second and third directions.

4. Positioning apparatus as claimed in claim 3 in which said first position adjusting means comprises a first control screw mounted on said first frame device with one end abutting said second frame device whereby rotation of said first screw causes deflection of said first pair of leaf springs.

5. Positioning apparatus as claimed in claim 4 in which said second and third position adjusting means comprise second and third control screws mounted in said second frame and arranged to deflect said second and third pairs of leaf springs, respectively.

6. Positioning apparatus as claimed in claim 1 in which said one jaw is provided with a resilient abutment plate secured to its inner face and an adjusting screw for controlling movement of said plate towards and away from said other jaw.

7. Positioning apparatus as claimed in claim 5 further comprising a supporting table on which said first frame device is pivotally mounted whereby said jaws and said first and second frame devices may be pivotally moved away from said table.

8. Positioning apparatus as claimed in claim 7 wherein two linear tracks are provided for slidably mounting said table thereon, each of said tracks having spaced stop devices for limited movement of said table between said spaced stop devices, said two tracks extending perpendicular to each other.

9. Positioning apparatus as claimed in claim 1 further including a microscope, the object held between said jaws being capable of being positioned and held at a desired position in the field of view.

References Cited UNITED STATES PATENTS 2,869,418 1/1959 Miller et al. 350 3,334,541 8/1967 Delp 35090 3,399,593 9/1968 Delp 35081 FOREIGN PATENTS 110,814 5/1928 Austria.

PAUL R. GILLIAM, Primary Examiner US. Cl. X.R.

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