US2646719A

US2646719A - Clamping device

Info

Publication number: US2646719A
Application number: US193081A
Authority: US
Inventors: Spriggs John Eric
Original assignee: Pictorial Machinery Ltd
Current assignee: Pictorial Machinery Ltd
Priority date: 1950-05-09
Filing date: 1950-10-31
Publication date: 1953-07-28
Anticipated expiration: 1970-07-28

Description

July 28, 1953 J. E. SPRIGGS 2,646,719

cumpmc DEVICE v Filed Oct. 51, 1950 s Sheets-Sheet 1 vIzmswf-ar- J. E. SPRIGGS CLAMPING DEVICE July 28, 1953 3 Sheets-Sheet '2 Filed Oct. 31, 1950 J. E. SPRIGGS CLAMPING DEVICE Jul 28, 1953 3 Sheets-Sheet 3 Filed OGL. 31, 1950 John Erl'c gar/' 7.: 1 6 (a. imam/z In red for Patented July 28, 1953 UNITED STATES OFFICE QLAMRING John Eric Spriggs; Iiondon Eng land;assignor-to Pictorial Machinery Limited, London, England;

aBri i h omp ny Application ctobe'r 31, 1950,v seal Ne; 193,081 In Great BritainfMay 9, 135 0 6' Claims. (02.33524) one part, so as to enable a catch on the arm to swing; with the arm in and out of engagement with an attachment member fixed on the other part, the catch arm also being capable of limited sliding movement forretraction and extension of the catch relatively to the pivot, whereby a re tractive movement of the arm when in its engaged position with the attachment member effects a closing together and clamping of the two parts, in combination with a cam-operated mechanism for producing automatically in sequence a swivelling movement of the catch arm to its engaged position and a sliding retractive movement of the arm for clamping together the two parts.

,7 -In the preferred construction, the catch arm has one end slotted in the direction of its length,

which slot is engaged by the pivot, so as to render the arm capable of a swivellin and sliding movement on the pivot.

The cam may bein the form of a slide, operated by means of a rack-and-piniondrive, and a cam track may be conveniently formed with a portion having a recess for freely receiving the vcam follower on the arm so as to enable the catch to move to its engaged and extended positions, another portion of the cam track having an abutment at one side of the recess for engaging the cam follower when the cam is moved in one direction so as to move the catch arm to its disengaged position, and the third portion of the camtrack having an inclined cam surface at the opposite side of the recess for progressively retracting the catch'arm when the slide is moved in the opposite direction. With this last construction, it is preferred todncorporate spring means for holding the cam follower in riding engagement with the cam track and also for resiliently acting on the cam follower to move the catch arm to its engaged and extended positions.

One construction in accordance with the present invention will now be described by way of example with reference to the accompanying drawings. The catch device is shown as a fitting on the copy-holder for clamping a glass cover thereto.

2 'I-nthedrawings,

Figure l is'a side-elevation showing a portion of thec'opy-holder with a catch device afiixed to 5 o'neside;

Figure 2 isa'cross-section on the line-22' of Figure 1; and

Figure 3 is an underside view of a portion of the 'copy-holder-showing a driving shaft for operating two cam slides at opposite sides of the copyholder, each such slide operating one or more catch'devices atthat side.

The copy-holder'- frame isshownat It and the glass-coverframe at H -'I o--one 'sideof the' copy holder frame Illis fitted a bolt l2 engaged through a hole It in the frame-l0-and-secured by a nut M. On the bolt 12 i-s-a spacer-sleeve15-. Tlie bolt 12' serves'as a pivot for one-endofastraight arm '16-. The catch arm is formed adjacent to one-end with a slot I! that extends inthe direction-of the length of the arm and which: is engagedover the-sleeve 15 on the bolt. The catch arm l6 is then capable of swivellingmovement-and alscrof linear-movement along its length on the bolt l2. The slotted end of the catch-arm is drilled-at I 8 to receive a compression spring l9 which'bears upon the sleeve I5 so as resiliently tomove the otherend of thecatch arm to an ext-ended'positionr This end of the arm is shaped in the formof ahook 2|] that serves as a catch.

- The-sleeve I 5 is fitted with an external ring 2| whichserves tospacethe catch arm Hi from the adjacent flange of the cover frame ID. On the spacer'ring is fitted acoi-l-spring2 2 looped at its 'ends23and z l round the catch arm [6 and the flange of the-frame- Ill. This spring 22 acts resili'ently to move the catch "arm ii to the upright engaged position shown in Figures 1 and 2. "-"The hooked-end 29 of the catch lever is adapted tcrbe engaged with a-hook 3.5.:at a lower end of an attachment. 26 fitted to the side. frame [I of the copy-holder cover. The hook3'5 is formed at the lower. end of. aplate kl fitted for vertical sliding movement'between the frame I I anda side member 'of' a bracket .26 havinga crank portion 28 ridingon top-ofthe:cover-frame. The bracket of theattachment Zitis clamped to the side member of the frame l: l:by means. ofa bolt. 29 engaged through registering holes in the frame and bracket member 21. The hook plate 25 is longitudinally slotted at 30 to pass the bolt 29. In this way the plate can be slid vertically, after releasing the clamping bolt 29, in order to adjust the slide of the hook 35. Raising and lowering of the plate 25 is effected by a set screw 3| engaged through the member 28 of the bracket and screw threaded at 32 into the top of the hook plate 25.

At each of two opposite sides of the copy holder frame is fitted a slide bar 33 guided for movement in the longitudinal direction of the slide. Each slide 33 is guided for longitudinal movement between fixed upper bearers 34 and flanged roller guides 36 mounted on supporting bolts 31 aflixed to the side flange of the copy-holder frame 10. The lower longitudinal edge of th slide 33 is engaged by a roller 38 fitted at the inside of the catch arm I6. This roller serves as a cam follower. The roller 38 is held in riding engagement with the edge of the slideby means of the coil spring 22.

The lower edge of the slide is formed along a part of its length with a cam track. This cam track incorporates a recess 39, which is of such a depth as to freely receive the roller 38 when the recess, roller and pivot l2 are aligned. The catch arm will then be moved to the position at II under the action of the compression spring [9. In this position the catch is thus in an extended position for free engagement with the hook 35. At one side of the cam recess 39 is a wall 40. When the slide shown in Figure 1 is moved towards the left, the roller 38 is engaged by this wall, which acts to swing the arm 16 into the disengaged position shown at I. In moving to the extreme position, the roller runs out of the recess 39, ofi the wall 20, and thence on to the straight lower edge of the slide 33. At the other side of the recess 39, opposite the wall 40, is a track portion in the form of an incline or ramp 50. This incline 5! terminates in a corner portion 51.

For moving the two slides 33 at the opposite sides of the copy-holder frame In, there is provided a transverse driving shaft 4| carried in bearings 42 on brackets 43 secured by bolts 44 to the side flanges of the copy-holder 10. The projecting ends of the driving shaft 4| are fitted with .pinions in mesh with racks 46 on the undersides of the slides 33. On one end of the shaft is a handle il. Rotation of the handle 41 in one or other direction will thus produce simultaneous linear movements of the two slides 33.

When each of the catch devices at opposite sides of the copy-holder frame is in a disengaged position the moving parts are in the position shown in chain lines, the position of the catch arm being shown at I. To move the catch arm into its engaged position at II, and subsequently into its clamping position at III, the driving shaft 41 is rotated so as to shift each bar towards the right of Figure 1 into the position shown in full lines. At the first stage of this linear movement of the bar, roller 38 runs down the wall into the recess 39. The catch arm is then automatically brought to the position shown at II. With continued movement of the slide 33, the roller rides up the incline or ramp 59. This produces a retractive movement of the catch arm, which slides downwardly, and the hook 20 is thereby drawn downwardly, pulling the hook 35 on the attachment 25 with it, so that the cover frame is brought into clamping engagement with the 6 copy-holder frame It], with the glass plate 5| of the cover in sealing contact with the top 52 of the copy-holder. When the two parts 10 and [I are fully clamped together, the roller 38 is locked within the corner portion 51 of the cam track.

I claim:

1. A catch device for clamping together two parts to form an article comprising a catch arm mounted for swivelling and sliding movement on a pivot adapted to be fixed to the one part of the article, an attachment member adapted to be fixed on the other part of the article for engagement by a catch on the arm, a cam follower carried by the catch arm, a slide, a cam track on the slide, and means for holding the cam follower in riding contact with the cam track on the slide, the cam track being shaped with an abutment and an inclined cam track to produce on movement of the slide automatically in sequence respectively a swivelling movement of the catch arm to an engaging position with the attachment member and a sliding movement of the catch arm to close together and clamp the two parts.

2. A catch device as claimed in claim 1, wherein the catch arm is substantially straight, with one end adapted to engage the attachment, and the other end portion slotted in the direction of its length, which slot is engaged by the pivot, so as to render the arm capable of swivelling and sliding movements on the pivot.

3. A catch device as claimed in claim 2, wherein the cam slide is formed with a cam track having a portion with a recess for freely receiving the cam follower on the catch arm so as to permit the arm freely to move to its engaging position, another portion of the cam track having the abutment at one side of the recess for engaging the cam follower when the cam has moved in one direction so as to swivel the catch arm away from its engaging position, and a further portion of the cam track having the inclined cam surface at the opposite side of the recess for progressively sliding the catch arm to its clamping position when the cam is moved in the opposite direction.

4. A catch device as claimed in claim 1, wherein the cam follower is held in riding engagement with the cam track by spring means acting resiliently to displace the catch away from its clamping position and to hold it in its engaging position.

5. A catch device as claimed in claim 1, wherein the catch on the catch arm is in the form of a hook, and the catch hook is adapted to engage a complementary catch hook of an attachment member, the hook of the attachment device constituting a portion of a slide adjustably fitted in a bracket so as to permit adjustment of the position of the hook.

6. A catch device as claimed in claim 1, wherein the catch slide is operated by a rack-and-pinion drive from a driving shaft.

JOHN ERIC SPRIGGS.

References Cited in the file of this patent UNITED STATES PATENTS a, "Mi