US 3559574 A
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Description (OCR text may contain errors)
UnitedStates Patent Inventor Albert George Ronald Gates Tottenham, England Appl. No. 801,906 Filed Feb. 20, 1969 Patented Feb. 2., 1971 As'signee Gestetner Limited London, England a Britishcornpany Priority Feb. 22, 1968 Great Britain 8764/68 CLAMP FDR SECUR N AN I NK TUBE TO A PRINTENQ INK 13 we"; 5 Drawing Figs.
1'01/366, 222/325: 285/242, 285/33 Int. Cl, B411 31/08 501 FieldofSearch 101/335,
366, 116, 119, 124; 248/(Inquired); 21l/(1nquired);222/8992, 325; 285/242, 243,
['56] References Cited UNITED STATES PATENTS 2,143,885 1/1939 Kline 101/366 2,143,886 1/1939 Kline 101/366 2,787,216 4/1957 Gates 101/366 Primary Examiner-Robert E. Pulfrey Assistant Examiner-J. Reed Fisher Attorney-Cushamn, Darby & Cushman ABSTRACT: A device for clamping an ink reservoir to a duplicator ink pump, including a slidable jaw to pull the reservoir nozzle against an ink conduit and a feeler movable across a mouth of the jaw to detect the presence of a partly inserted nozzle and either to push the nozzle home or to prevent further sliding of the jaw.
CLAMP FOR SECURING AN INK TUBE TO A PRINTING PRESS INK PUMP The present invention provides an improvement relating to printing apparatus and more particularly relates to an improved clamping device for securing an ink tube to printing apparatus. such as a stencil duplicator Throughout this specification the term ink tube" is intended to represent an ink reservoir of the type comprising a collapsible container having a nozzle which is intended to be pulled firmly into engagement with an ink duct or pipe along which ink is to be sucked from the container by the ink pump of the apparatus.
According to the present invention we provide a device for clamping an ink tube in relation to an ink supply passage of printing apparatus. such device comprising an ink conduit communicable with said ink supply passage; an open sided jaw axially slidable with respect to said ink conduit and provided with an inwardly extending rib for engaging the underside of an ink tube nozzle and a nozzle access passage for permitting lateral sliding of a nozzle into a position on said jaw coaxial with said ink conduit; means for effecting clamping movement of said jaw axially towards the ink conduit; and a feeler member arranged to sense the presence of an ink tube not fully inserted into the jaw, said feeler member being effective either to move the ink tube into the fully inserted position or to prevent further movement of the jaw towards its fully clamped position until the partly inserted ink tube has been sufficiently inserted into the jaw.
Preferably the feeler member may be mechanically linked to a clamp operating lever whereby movement of the clamp operating lever to a clamping position will effect tube sensing movement of the feeler member across the mouth of the nozzle access passage. Desirably the clamp operating lever may be arranged for camming engagement with the axially slidable jaw to effect upward sliding movement of the jaw upon movement of the clamp operating lever in an appropriate direction.
In one suitable embodiment of the invention the feeler member and the clamp operating lever may be formed as an integral structure. The clamp operating lever and the jaw may be linked by a camming mechanism comprising a cam plate pivotally mounted with respect to the body of the ink pump and provided with an arcuate slot which has its concave side facing the axis of pivoting of said cam plate and is arranged so that the ends of the slot are differently spaced from the pivoting axis, said clamp jaw having a guide member projecting snugly into the arcuate slot whereby pivotal movement of the cam plate causes movement of said guide member towards or away from the axis of pivoting and results in movement of the slidable jaw. Conveniently the guide member may comprise a screw engaged in the threaded recess in the wall of the sliding jaw, such screw having a head larger than the transverse dimension of said slot.
In an alternative embodiment of the invention the feeler member may comprise a lever pivotally mounted on the axially slidable jaw and driven by abutting engagement with the clamp operating lever to pass across the tube access passage as the clamp operating lever is pivoted. In this case the feeler lever may suitably be of L-shaped form and pivoted at the free end of one of the limbs, the other limb of the L constituting the feeler, and the first mentioned limb of the L being provided with an arcuate extension which, when assembled together with the remainder of the device, is arranged to lie above the comer of the L and to cooperate with the clamp operating lever to provide a camming engagement for effecting sensing movement of the feeler.
In order that the present invention may more readily be understood, the following description is given merely by way of example, reference being made to the accompanying drawings in which:
1 FIG. I is a side elevational view of an ink pump of a stencil duplicator, the pump of which incorporates the clamp of the present invention here shown in the closed position;
FIG. 2 is a view, similar to FIG. 1, but showing the clamp in the open position, the remainder of the components of the pump being omitted;
FIG. 3 is an underneath plan view of the ink tube clamp shown in the FIG. 2 position;
FIG. 4 is a perspective view of a second embodiment of clamp of this invention. showing the clamp in the open condition; and
FIG. 5 is a view similar to FIG. 4, but showing the clamp in closed condition.
Referring now to the drawings, and in particular to FIG. 1, there is shown an ink pump comprising a pump body I having a downwardly extending clamp support 2 which carries a pivotally movable slotted cam plate 3 having an operating lever 4.
An arcuate slot 5 in the cam plate has a screw 6 extending therethrough and threadedly received in a vertically movable clamp body 7 which is reciprocatable longitudinally of the ink inlet duct 8, extending downwardly from the clamp support 2. The lower wall of the clamp body 7 includes a clamping flange 11 having an upper surface 10 which bears against a suitably formed bearing surface on the underside of an ink tube nozzle.
The cam plate 3 is mounted on the clamp support 2 by means of a laterally extending boss 9 formed on the back surface of the cam plate 3, and engaging in a suitably formed recess in the front wall of the clamp support 2. The curvature of the slot 5 is such that the distance of the axis of the boss 9 from the point A at one end of slot 5 is greater than the distance between the axis of the boss 9 and point B at the opposite end of the arcuate slot (see FIG. 2) thus, upon anticlockwise rotation of the cam plate 3 from the FIG. 1 position the screw 6 fitting snugly within the slot 5 is caused to descend, carrying with it the clamp body 7.
FIG. 2 shows the lowered position of the clamp body 7 in which the operating lever 4 of the cam plate is in its raised position. As shown in this FIG. the clamp body 7 has descended relatively to the ink duct 8 so that the clearance between the lower end of the duct 8 and the upper surface 10 of the clamping flange 11 is greater than was the case in FIG. 1.
The screw 6 has a comparatively large diameter flat head 60 which bears inwardly against a strip steel spring 12 disposed substantially parallel to the plane of the cam plate 3 and having at one end a tongue 13 which engages within a slot formed in a lug 14 formed on the pump body. The spring 12 serves both to retain the cam plate 3 in position on the clamp support by preventing movement of the cam plate away from the surface of the clamp support, but also the spring is formed in a slightly bowed configuration so that the center of the spring is displaced from the plane joining the ends of the strip 12, so that the central part of the spring bears firmly against the front of the cam plate and exerts a frictional force resisting rotation of the cam plate 3. This has the effect that when the clamp body 7 is in its raised position and the cam plate has been rotated to the FIG. 1 configuration, any tendency for the clamp body 7 to be lowered, by virtue of the bearing force of the shoulder of an ink tube against the upper face 10 of the clamping flange 11, will be resisted since such downward movement of the clamp body 7 will necessitate rotation of the cam plate 3. Thus, apart from the natural geometric lock effect created by the slot 5, and screw 6 arrangement there will also be the additional friction exerted by the center of the spring 12 bearing on the front face of the cam plate 3.
The screw 6 has a shank which has a wider diameter portion near the head, such portion engaging snugly within the slot 5, but the free end of the shank is of a reduced diameter and has threads formed thereon for engagement in a suitably formed threaded recess in the clamp body 7.
may be exerted in order to rotate the cam plate upon insertion of an ink tube. The cam plate 3 is also provided with an extension 16 having a perpendicularly extending lug 17 which, as shown in FIGS. 2 and 3, forms a continuation of the lateral all 18 of the nozzle-receiving recess formed in the clamp body, the edge 15 between the cam plate extension 16 and the lug 17 being radiused as shown in FIG. 3. This lug thereby provides a means of guiding the nozzle of an ink tube into position within the nozzle receiving recess. and when the control lever 4 is moved downwardly to its FIG. 1 position the lug l7 and the extension 16 pass across the opening of the nozzle receiving recess and push the nozzle of an Ink tube in the aperture firmly into position in which the ink tube nozzle is concentric with the lower end of the ink duct 8.
As the clamp body 7 is moved upwardly during the clamping operation the nozzle of an ink tube is also urged upwardly by engagement of the bearing surface on the underside of the nozzle with the nozzle bearing wall of the flange 11, the nozzle of the tube thereby being urged against the lower end of the ink duct 8. Conventional ink tubes are provided with a resilient washer set into the upper wall of the nozzle, this washer providing a seating against which the lower face of the ink duct 8 can engage and bear in order to provide an airtight seal between the ink tube and the ink duct 8.
As shown in FIGS. 1 and 2, as the cam plate 3 rotates between the FIG. 2 and FIG. 1 positions, not only is the clamp body 7 raised, but also the strip spring 12 is urged upwardly so that the tongue 13 protrudes further into the slot in the lug 14.
By way of further explanation the operation of the above described ink tube clamping device will now be described. Initially the control lever 4 is moved to its raised position in which the clamp body 7 is lowered and the clearance between the lower wall of the ink duct 8 from the upper bearing face 10 of clamping flange 11 is at a maximum. In this position, as described above, the lug 17 forms a continuation of the sidewall 18 of the nozzle receiving recess.
The noule of a full ink tube to be inserted in the machine is then guided along the leftward laterally facing surface of the lug 17 and along the sidewall 18 of the recess until it is in position within the nozzle-receiving recess so that the nozzle is coaxial with the ink duct 8.
In this position the control lever 4 may be moved downwardly so that the rear wall of the extension 16 of the cam plate 3 is able to pass across the front of the nonlereceiving recess and move clockwise into the FIG. 1 position. In the latter position the clamp body 7 is at its highest point and the bottom of the ink duct 8 is urged firmly into engagement with the resilient washer of the ink tube nozzle. The ink pump may then be operated and ink drawn from the ink tube up into the inking mechanism of the duplicaton,
In the event that the noule of the full ink tube has not been moved far enough into the nozzle-receiving recess for operation of the pump, downward movement of the control lever 4 will cause the radiused edge between the leftward wall of the lug 17 and the rear wall of the extension 16 to strike the ink tube nozzle during lowering of the control lever 4. Impact of this radiused edge 15 will either push the ink tube nozzle laterally into position within the nozzle receiving recess, or will cause the ink tube nozzle to be jammed between the radiused edge 15 of the extension 16 and the corner 19 at the lower lefthand edge of the clamp body 7. Such jamming will easily be detected by the operator of the duplicator since it will be impossible to move the control lever 4 to its fully downurd position. There will therefore be no likelihood of the stencil duplicator being operated before the tube is correctly in position. In the event of such jamming of the ink tube nozzle the control lever 4 must be raised to free the noule and then the nozzle should be pushed laterally into the correct position in which it is coaxial with the ink duct 8. Once the tube has been pushed into the correct position the control lever 4 may then be lowered thus raising the clamping body 7 to hold the full ink tube in position in the duplicator.
In conventional duplicators the tube was clamped by a similar clamp body 7 moving upwardly into engagement with a clamp support 2, but the cam plate mechanism was mounted on the side of the clamp support 2 instead of on the front, and also the clamp was able to be operated even if the nozzle of a full ink tube were not pressed fully home into its coaxial position with respect to the ink duct 8. Thus it was possible for the clamp body 7 to be raised, urging the upper part of the full ink tube into engagement with the lower sealing edge of the ink duct 8 and, if the tube nozzle were badly out of line with respect to the ink duct then considerable damage could be incurred by the top sealing face of the nozzle, rendering that particular tube unusable. With the apparatus illustrated it is impossible to raise the clamp body 7 until the ink tube nozzle has been placed in its correct position coaxially with the ink duct 8 and moreover, if it should occur that the ink tube nozzle is jammed between the comer 19 and the radiused edge 15 of the projection 16, then the only damage sustained by the tube nozzle would be on the lateral wall of the nozzle rather than on the upper sealing face where such damage might be critical.
The clamp of the present invention is advantageously of die cast construction so that the clamp body 7 and the clamp support 2 are separately cast components. The ink duct 8 is mounted within the clamp support 2 by any suitable means and is fixed with respect thereto.
The integral unit comprising control lever 4, cam plate 3 and extension 16 together with its lug 17 is advantageously moulded of a plastics material. However, this choice of materials for the various components of the clamp is preferable and is not intended to limit the invention in any way.
FIG. 4 shows a perspective view of an alternative form of ink tube clamp comprising a clamp operating lever 21 pivoted by means of two screws 20 engaging in the upper part of the clamp body and passing freely through respective ears 22 of the clamp operating lever 21. The lower parts of the ears 22 are provided with recesses 5' on their inner faces, similar to the slot 5 of the previous embodiment and engaging with suitable pegs 6 formed on the slidable lower clamp member or jaw 24.
A blanking lever 23 is pivotally mounted by means of a screw 25 to the front of the lower slidable clamp member so as to be able to swing across the front access aperture of the slidable clamp body. The lever 23 is of L-shape having a rounded edge 26 to force home an ink reservoir tube which might have been inadvertently only half inserted in the aperture before operation of the clamping mechanism. The corner 27 of the L is, in the open position of FIG. 4 disposed directly below the lower edge 28 of the associated car 22 of the clamp operating lever. Moreover, the blanking lever 23 is provided with an arcuate upper extension 29 having a tip 29' which lies above the upper edge 30 of the associated ear 22. The arcuate extension 29 is also provided with a transversely extending peg 31 shown more clearly in FIG. 5 as being able to cooperate with an aperture 32 formed in the clamp operating lever 21.
The operation of this second embodiment of clamp is as follows:
As the clamp operating lever 21 is pivoted in the clockwise sense about the screws 20, the cooperating action of the recesses 5' and the associated pegs on the slidable clamp jaw 24 causes the clamp jaw 24 to rise, in the same manner as in the embodiment of FIGS. 1 to 3. Such pivoting of the lever 21 causes raising of the slidable clamp jaw 24 carrying the blanking lever 23 and simultaneous lowering of the associated car 28 of the clamp operating lever, thereby urging the lower edge 28 of the car into abutting engagement with the comer 27 of the blanking lever, to cause clockwise pivotal movement of the blanking lever about the screw 25. In so doing, the curved edge 26 of the blanking lever will either force home a partly inserted ink tube, or will be obstructed by such ink tube to prevent further clamping movement of the clamp operating lever 21.
During the clockwise pivoting of the blanking lever 23 the tip 29 will descend remaining adjacent to the descending upper edge 30 of the ear 22. This motion will continue until such time as the slidable clamp jaw 24 has reached its upper limit of travel and further movement of the clamp operating lever is blocked.
Upon releasing movement of the clamp operating lever 21 the cooperation of the slot 5' and associated peg will cause downward movement of the clamp jaw 24 and simultaneously the cooperation of the upper edge 30 of the ear and the adjacent tip 29 of the blanking lever will initiate anticlockwise 5 pivotal movement of the blanking, lever about the screw 25. Thus the peg 31 will move to the left as viewed in FIG. 5. until such time as the upper edge 30 of the ear slides over the tip 29' and is unable to exert any further anticlockwise pivotal 31 will be in register with the mouth of the slot 32 so that further upward movement of the clamp operating lever 21 will cause the lower edge of the slot 32 to bear upwardly and left wardly against the pin 31 urging the pin further in the leftward direction until the FIG. 4 position is reached.
The construction of FIGS. 4 and 5 has the added advantage that unlike the embodiment of FIGS. 1 to 3 the second embodiment has no requirement for access of an operators hand to the side of the device.
1. A device for clamping an ink tube having an outlet nozzle provided with projecting means having an underside in relation to an ink supply passage of printing apparatus. such device comprising in combination:
a. ink conduit means communicable with said ink supply passage;
b. open sided jaw means axially slidable with respect to said ink conduit between a clamping position and a releasing position;
c. an inwardly extending rib on said open sided jaw means for engaging the underside of said ink tube nozzle projecting means;
d. nozzle access passage means permitting lateral sliding of said ink tube nozzle into position on said jaw means coaxial with said ink conduit;
e. means for effecting clamping movement of said jaw means axially towards said ink conduit; and
f. movable feeler means for sensing the presence of said ink t-ube when not fully inserted into the jaw means, said feeler means being coupled to said jaw moving means to prevent movement of the jaw means into fully clamped position when the ink tube nozzle is not fully inserted.
2. A device according to claim 1, wherein the nozzle access passage means has at least one wall for guiding the nozzle during insertion thereinto, and wherein said feeler means comprises guide surface means thereon to form a continuation of said nozzle access passage means wall when said jaw means are in said releasing position.
3. A device according to claim 1, and including abutment means formed on said feeler means for pushing home said nozzle when said nozzle is in a partly inserted position with relation to said jaw means. i
4. A device according to claim 1, wherein said jaw moving means comprises a clamp operating lever movable between a clamping position and a releasing position and mechanically linked to the feeler means whereby movement of the clamp operating lever to said clamping position will effect tube sensing movement of the feeler means across the mouth of the nonle access passage means.
5. A device according to claim 4, wherein the feeler means and the clamp operating lever are formed as an integral structure.
6. A device according to claim 4, wherein the feeler means comprises a lever pivotally mounted on the axially slidable jaw means and drivable by abutting engagement by the clamp operating lever to pass across the tube access passage means moment on the blanking lever. However. by this time the peg l as the clamp operating lever is pivoted between the clamping and releasing positions.
7. A device according to claim 6. wherein the feeler lever is of L-shaped form comprising:
g. a first limb; h. pivotal mounting means near the free end of said first limb j. a second limb perpendicular to the first limb and con stituting a feeler member; and
k. an arcuate extension on said first limb which lies above the corner of the L and cooperates with the clamp operating lever means to provide a camming engagement for effecting nozzle sensing movement of the feeler.
8. A device according to claim 7. and including an ear formed on said clamp operating lever means for abutting engagement with said first limb for camming movement towards said clamping position and for abutting engagement with said arcuate extension for camming movement towards the releasing position.
9. A device according to claim 8, and including:
l. cam slot means formed in said operating lever means; and
m. a peg on said arcuate extension and engageable with said cam slot means, whereby said abutting engagement of the ear with the extension is augmented by engagement of said peg and said cam slot means.
10. A device according to claim 4. and including cam means connected between the clamp operating lever means and the axially slidable jaw means. for effecting upward sliding move ment of the jaw means upon movement of the clamp operating lever means from the releasing position to the clamping position.
11. A device according to claim 10, wherein said cam means. comprises:
n. a cam plate pivotally mounted with respect said ink conduit means;
0. an arcuate slot formed in said cam plate and having a concave side facing the axis of pivoting of said cam plate and arranged with the ends of the slot differently spaced from said pivoting axis; and
p. a guide member projecting snugly into said arcuate slot whereby pivotal movement of the cam plate causes movement of said guide member towards or away from said axis of pivoting movement and results in movement of the slidable jaw means.
12. A device according to claim 11, wherein said guide member comprises:
q. threaded recess means in the wall of the sliding jaw means;
r. a screw;
5. a threaded shank of said screw arranged for threaded engagement with said recess means and having a diameter substantially equal to the transverse dimension of said slot; and
t. a head on said screw larger than said transverse dimension of the slot.
13. A device according to claim 12, in combination with said printing apparatus which has an ink pump with a body and further including:
u. a resilient strip through one end of which said shank of the screw passes; and
v. suitably formed aperture means in the pump body slidably receiving the other end of said strip, the strip being bowed whereby the midpoint of the strip is displaced from a plane joining the ends of the strip and the strip being assembled with respect to the cam plate with the midpoint of the strip bearing against the cam plate.