US 3356364 A
Description (OCR text may contain errors)
H. GRIGEREIT 3,356,364
FEED CATCH FOR APPARATUS HANDLING SHEET MATERIAL Dec. 5, 1967 Filed July 6, 1965 l av NN! W51 0% GUI ML. mt m W MNH h Wm WM w... Mr In II 6 m m H M United States Patent assigna Swiss com- Filed July 6, 1966, Ser. No. 563,199 Claims priority, application Switzerland, July 12, 1965, 9,726/ 65 4 Claims. (Cl. 271-60) ABSTRACT OF THE DISCLOSURE Apparatus to ensure that a sheet of paper is fed in straight to an office machine comprises a plurality of check levers arranged in spaced relation transversely of the direction of feed of the paper and which are rigidly secured to a spring loadedcross shaft which tends to retain all check levers in a position blocking passage of the paper sheet. Associated with each check lever is a pawl which when released from its retaining slot by contact with the leading edge of the paper sheet permits the leading edge to then engage the corresponding check lever and raise it out of its retaining slot thus rotating the check lever out of the path of travel of the sheet. The arangement is such that only when the paper sheet is fed in straight are all of the pawls released simultaneously thus to permit all check levers to be actuated simultaneously to a position allowing the sheet to be passed by the levers. Should an attempt be made to feed the paper sheet in a slanted manner relative to the line of pawls so that one or more of the pawls remains latched in its retaining slot, none of the check levers can be actuated and thus the paper sheet is prevented from being fed into the machine.
This invention relates to a feed catch for apparatus handling sheet material to ensure that the sheets to be processed are fed in straight.
In apparatus handling sheet material, such as oflice copying machines, typewriters, time check clocks, etc., manual operation frequently causes failure because sheets are notfed into the apparatus in the correct position. Stops and guides which have been provided in such apparatus in most cases permit only a limited straightening and centering of the sheet material and require a certain amount of skill and practice on the part of the operators. Moreover, they take up space and are often difiicult to adjust.
Various devices have therefore been proposed for autoice plane of the sheet feed while the feelers are above this plane. The feelers consist of the pawls which are rotatably mounted and drop into cams on the check levers; they can be operated individually by the respective sheet edges and are turned about their axis by the forward movement of the sheets, whereby they become disengaged from the cams on the check levers. The edge of the sheet comes up against the cam of the check lever and, n consequence of the common shaft of the check levers, it can only be pushed on further when all feelers are d1sengaged. As a result of the further advance of the sheet the check levers are pushed downwards against the torque of a spring. If the sheet feed is not correct, i.e. on the slant, the projecting edge comes up against the camof the corresponding check lever and subsequently causes the sheet to be turned round until all the feelers are released. If the distance between the front edge of the feeler and the cam of the check lever is kept small, possible error in the feed becomes negligible.
This system, which is inherently simple, has however a number of defects. In the first place the check lever and the feeler are disposed on different sides of the plane of the sheet feed which entails extra problems with regard to sheet transport and also necessitates and thus expensive installation. To overcome the height of the cam, the sheet has to drive the check lever over a rela tively long distance and this raises problems of stability and transport, particularly in the case of thin sheets of paper. After the catch has beenreleased the check lever and the feeler are no longer in contact with one another,
. and steps have to be taken to ensure the reliable re-engagement of these two elements once a sheet has passed through the device. This means that the elements referred to have to be precision manufactured, exactly adjusted and the restoring forces must be relatively strong. This means that the releasing forces have to be equally strong. The releasing forces have to be supplied by the edge of the sheets being fed in, which can easily lead to damage to the sheets in the case of flimsier papers, such as air mail papers.
The object of the invention is a simple feed catch for sheet material which obviates the above-described disadvantages and, While requiring little space, secures a perfect and straight feed-in of the individual sheets.
According to the invention there is provided a feed catch device for ensuring straight feed of sheet material matically securing straight feed. In these devices at least two feelers are disposed on a straight line at right angles to the direction of the sheet feed and can be operated by the front edge of the sheet and only after simultaneous operation do the feelers release a catch fitted immediately behind the feelers and permit the feed to continue. Electrical contacts, e.g. two contacts which have to be opened by the edge of the sheet, a light source with photocell, or mechanical sensing members are used as feelers. Connection between the catch and the feeler can be established by electrical, electromagnetic or mechanical devices.
If the cost of the arrangement is of importance, as is probably the case with simple oifice copying machines, only mechanical feelers in conjunction with mechanical catches can be considered. In a proposed construction the catches consist of check levers situated opposite one another at a distance less than the width of the sheets and connected through a common shaft with one another so as to be rotatable together. The device is so arranged that the check levers and the common shaft are below the comprising, in combination,
(a) A base plate,
. (b) First and second side members mounted on base plate,
(c) A shaft positioned between said side members and mounted in said side members for rotation, said shaft being spaced apart from said base plate, and normal to the intended direction of feed of sheet material,
(d) Areas of said base plate defining a plurality of first slots,
(e) A plurality of check levers mounted on said shaft for rotation therewith, each check lever having a lower edge, and each lower edge being engageable in a different first slot in said base plate,
(f) Areas of said base plate defining a plurality of second slots,
(g) A plurality of pawls; each pawl being rotatably connected to a different check lever and being engageable in a different second slot in said base plate, release of said I the feed catch being enabled only when all said pawls are released from their associated second slots, allowing movement of all of the check levers from their associated first slots.
Preferably the first and second slots are parallel to the intended direction of feed of sheet material, the first slots being in staggered relationship with the second slots and with the one end of each of the first slots being colinear with one end of each of the second slots.
Specific embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which:
FIGURE 1 shows the feed catch in perspective view;
FIGURE 2 shows a section along the line AA of FIGURE 1 with the feed catch in the neutral position;
FIGURE 3 shows the same section as FIGURE 2 but with the feed catch in the operational position;
FIGURE 4 shows another embodiment of the feed catch.
Two boards 2 and 2' are mounted on a base plate 1 and a shaft 3 is rotatably mounted in the said boards. Two check levers 4 and 4 are rigidly connected with the shaft 3 and in the neutral position their lower edges engage in the slots 10 and 10' respectively of the base plate. In this arrangement the length of the slots 10 and 10 is made such that in the neutral position the check levers strike the base plate but on rotation of the common shaft 3 in the counterclockwise direction (as viewed in FIG- URES 2 and 3) they can be turned out of the slots (FIG- URE 3).
Two pawls 6 and 6' are rotatably connected with the check levers 4 and 4, respectively, by means of studs and 5' and are adapted to engage in slots 11 and 11' respectively of the base plate 1. The slots and 10' and 1-1 and 11 are preferably parallel and are displaced in relation to one another in such a way that the leading edges of the slots 10 and 10' and the trailing edges of the slots 11 and 11 are colinear.
One end of a spring 8 is fixed to the board 2 by means of a spring pin 9 while the other end of the spring is connected to a spring saddle 7 which in turn is rigidly connected with the shaft 3.
The method of operation of the feed catch according to the invention will now be described with reference to FIGURES 2 and 3. If, at first, an attempt is made to insert a sheet 12 into the feed catch in a slanting, i.e. incorrect position (FIGURE 2), the sheet 12 will release the pawl 6 from the base plate 1 but is prevented from moving any further forward by the check lever 4. The check lever 4 cannot beswung out of the slot 10 since this would result in the counterclockwise rotation of the shaft 3, which however is prevented by the fact that the pawl 6' is still in the engaged position. Only when the pawl 6' has also been released, which is only possible if the sheet is fed in straight, does the pressure of the sheet 12 on the check levers 4 and 4' cause the rotation of the shaft 3 and consequently the swinging of the check levers out of the slots 11 and 11, whereupon the sheet can then be pushed through the feed catch without further trouble (FIGURE 3). The counterclockwise rotation of the shaft 3 takes place against the force of the spring 8 which exerts an opposite torque on the shaft, by way of the spring saddle 7, and after the sheet has passed through the feed catch causes the check levers 4 and 4 and the pawls 6 and 6' to return to their neutral position.
To ensure correct functioning of the feed catch, the width of the paper to be inserted must be at least the distance between the two slots 11 and 11. However, even the arrangement shown in FIGURE 1 does not give suflicient protection against the introduction of sheets of smaller width which can be pushed into the apparatus between the two check levers. This disadvantage can easily be eliminated as shown in FIGURE 4, by disposing one or more supplementary pawls and check levers of the same type between the two outer pawls (FIGURE 1). In the device of FIGUREA two extra pawls are provided, the individual components of which bear the same figures as those in FIGURE 1 but have the index and respectively. Their method of operation is the same as that of the above-described pawls. The sheet feed continues to remain blocked-until all the pawls 6, 6', 6" and 6" have been released, which implies that the sheet material to be introduced must then have a certain minimum format.
The feed catch in FIGURE 4 has the further advantage of a more uniform distribution of pressure on the front edge of the sheets, which is favourable, particularly when very thin sheets are being fed in, since undulation of the sheets in the middle thereof can be prevented.
The appropriate selection of the distance between the two boards 2 and 2' can be used to limit the maximum size of the sheets to be introduced.
Finally, it is self-evident that a sheet forwarding system must be disposed directly behind the feed catch so that any subsequent shifting of the direction of feed of the sheets can be prevented. Sheet forwarding systems which can be considered are rollers, grippers, electrostatic or magnetic forwarding elements or any other known sheet transport system.
By comparison with the previously proposed sheet feed catch, the system according to the invention has the advantage that pawls and check levers are disposed on one and the same side of the sheet feed plane, so that a fiat base plate can be used. This prevents damage due to buckling, tearing, etc., even of thin sheets, and the forces required to release the catch are considerably smaller than in proposed mechanical systems of this kind. Even while being operated, the pawls and the check levers remain connected with one another and so there are no problems of adjustment to ensure re-engagement.
What is claimed is:
1. A feed catch device for ensuring straight feed of sheet material comprising, in combination,
(a) a base plate,
(b) first and second side members mounted on said base plate,
(c) a shaft positioned between said side members and mounted in said side members for rotation, said shaft being spaced apart from said base plate, and normal to the intended direction of feed of sheet material,
(d) areas of said base plate defining a plurality of first slots,
(e) a plurality of check levers mounted on said shaft for rotation therewith each check lever having a lower edge, and each lower edge being engageable in a dilferent first slot in said base plate,
(f) areas of said base plate defining a plurality of second slots,
(g) a plurality of pawls; each pawl being rotatably connected to a dilferent check lever and being engageable in a different second slot in said base plate, release of the feed catch being enabled only when all said pawls are released from their associated second slots allowing movement of all the check levers from their associated first slots.
2. The device of claim -1 wherein said first and said second slots are disposed parallel to each other and parallel to the intended direction of feed of sheet material, said first slots being in staggered relationship with said second slots and with one end of each of said first slots being colinear with one end of each of said second slots.
3. The device of claim 2, wherein said side members consist of boards mounted on said base plate parallel to the intended direction of feed of sheet material, the distance between the boards determining the width of sheet material which can be passed through the device.
4. The device of claim 3, and comprising spring means mounted to urge the shaft in such a direction that the check levers normally are in engagement with their associated first slots.
References Cited UNITED STATES PATENTS 2,328,943 9/1943 Backhouse 271-60 X EDWARD A. SROKA, Primary Examiner.