GB2189734A - Stapling head - Google Patents

Abstract

A stapling head 30 for the stapling-together of flat-lying piles of paper by means of a U-shaped staple 1, with a magazine 6,8 for holding bars of parallely disposed and separably connected staples 1, a drive 38, driving a single staple 1, after it has been separated from a bar of staples 1, through the pile of papers to be stapled, is characterized in that a reciprocating parting device 31 is provided for separating a staple 1 from the bar of staples and transporting it towards a stapling channel 34, said parting device 31 acting from inside (ie from the legs side) on the yoke 14 of the U-shaped staple. This dispenses with the need for a staple pusher, and the stapler can be refilled with bars of staples without an interruption in work. Rams 40, working in advance of the driver 38, swing the legs of the staple 1 to align the staple vertically in the channel 34. The parting device has a stop face which strikes the yoke 14 and a support face for transporting the separated staple. <IMAGE>

Description

SPECIFICATION Stapling head The invention relates to a stapling headforthe stapling-together offlat-lying piles of paper by means of a U-shaped staple, said staple comprising two legs pointing towards one side and, between said legs, a yoke, with a basically vertically deposed magazine for holding bars of staples with a plurality of parallel deposed and separately connected staples, with a parting device, said parting device acting on the yoke of the staple in order to separate a staple from the bar of staples, and with a driver, said driver driving a single staple, having been separated from a bar of staples, through the pile of papers to be stapled.

The aforementioned bars of staples consist of individual preformed and glued4ogetherstaples. In known staplers, these bars of staples are, with their longitudinal direction, parallel to the pile of papers to be stapled, i.e. they are generally horizontal and are stored in a magazine. The driver serves also to separate from the bar of staples the single staple required for stapling. In doing so, the driver presses on the outside of the joke or back of the U-shaped staple, which comprises two straight legs and a straightjoke joining the latter. The bars of staples are preloadedfromtheirendfacing awayfromthedriver by a spring-loaded staple slide and are, afterthe execution of each stapling operation, moved forward by the width of a staple.

To refill the stapler with bars of staples, it is necessary to pull back the staple slide, in many designs to release from the stapler, to insert a new bar of staples into the magazine and to bring the staple slide into engagement with the newly inserted bar of staples. It is, therefore, not possible to work continuously with known staplers, because stapling has to be interrupted when a new bar of staples is put into the magazine. The staple slide, which exerts a considerable force on the rear end of the bar of staples, is necessary in order, when the driver strikes the outside of the joke ofthe staple being separated, to prevent the bar of staples, particularly if there are only a few staples left in it, from tilting, thereby rendering satisfactory stapling impossible.The staple, supported by the staple slide, that is nearest to the staple that has just been parted off by the driver forms, at least during some of the motion of the driver, a guide for the staple that has been separated by the driver from the bar of staples.

In a stapler without staple slide known from US-A 3748717, the parting device acts likewise from outside (i.e. from the sidefacing awayfrom the legs) on the joke. In cases where the bar of staples comprises only a few remaining staples, the latter may tilt, as a result of which malfunctions are possible.

The object ofthe invention is to create a stapling head of the initially described kind, said stapling head being suitable in principle for dispensing with the need fora spring-loaded staple slide, this making it possible to put a bar of staples into the magazine during the operation of the stapler, with operational malfunctions when a bar of staples comprises only a few remaining staples being precluded.

This object of the invention is achieved in that the parting device is guided such that it acts on the joke from the legs side and the driver is a separate part from the parting device.

In this connection, the staple that is to be parted off is in contact with a surface with its free end face, i.e.

with that side that is not in contact with the bar of remaining staples. The parting device, which acts on the inside ofthe joke between the two legs ofthe staple, likewise produces a torque acting on the staple that is to be parted off, this being due to the glued connection between the staple that is to be parted off and the bar of remaining staples.

However, this torque has a tendency to press the free ends ofthe iegs ofthe staple being parted off more firmly against the aforementioned surface ofthe stapling head, with the result that there is no tilting of the staple.

It is not necessarytherefore, for a considerable force to be exerted on the free end of the bar of staples in order to prevent tilting of the staple that is to be separated. Therefore, a spring-loaded staple slide is not required, this making it possible for bars of staples to be inserted into the magazine during the operation of the stapler. The moving of the bar of staplestowardsthe parting device after each staple is parted off does not call for any great forces and can, in the simplest case, be effected by the force of gravity if the longitudinal direction ofthe magazine and the longitudinal direction of the bars of staples are basically vertical.

In the invention, the staple cannot be driven in the same direction of motion in which the parting device separates the staple from the bar of staples. Thus, unlike the known stapling heads, the parting device cannot be used as the driver. The invention opens up numerous possibilities of how a driver, contained in the device, can drive the single staple that has been separated from the bar of staples into the papers that are to be stapled.

In an embodiment of the invention, the direction of motion ofthe parting device, together with the direction of motion of the driver, encloses an angle, and a device is provided for swinging through the aforementioned angle the staple that has been separated from the bar of staples. The aforementioned angle may be preferably approximately 90'.

This embodiment makes it possible, for example, in the above-described mannerforthe magazine to be disposed basically vertically, with the legs ofthe staples contained in the bar of staples extending horizontally, and for stapling with the staple that has been separated from the bar of staples still to be executed in a vertical direction.

The device for swinging may be of particularly simple design if it is so designed that the joke ofthe staple forms the swivel axis for the staple. This means that the staple can be stored with particular ease during the swinging operation.

In an embodiment of the invention, the parting device comprises at least one slide, said slide, atthe start of the separation ofthe staple from the bar of staples, contacting with a stopfacethe inside ofthe joke ofthe staple and embracing with a supportface the free end face of the joke of the staple still connected to the bar of staples. Consequently, particularly if the slide moves in a horizontal direction, it is possible for the support face to hold the staple that has already been separated from the barofstaplesandto move itto a position in which the driver can act on the staple. Beforehand,the staple must have been swung such that its legs extend parallel to the direction of motion ofthe driver.In general, this will involve the slide covering a distance that is at least as long as the length ofthe longest-possible legs of staples that can be used in the stapler in question, so thatthe ends of the legs come free from a support face supporting the free end face of the staple that is to be separated from the bar of staples.

Even if the device is so designedthattheforce of gravity might in principle effect the swinging of the staple, having been separated from the bar of staples, into its correct position for being driven into the pile of papers, it may still be practical, according to an embodiment of the invention, for the stapling head to comprise a reversing ram for swinging the staple, said reversing ram being displaceably guided basically parallel to the direction of displacement of the driver and, after the staple has been swung, forming a guideforthe staple to be moved bythe driver. This resu Its in a high degree of reliability in the operation ofthe device.

In an embodiment of the invention, the free end face of a staple still connected to a bar of staples is, when in its position for being separated from the bar of staples, in contact with a face of a magnet. This can prevent an undesired change in the position of the staple.

In an embodiment of the invention, a driving device is provided for the slide of the parting device, said driving device bringing said slide out of engagement with the staple before the driver moves the staple. This promotes the low-noiseoperation of the device. It is also possible to use the driverto bring the slide out of the way of the staple.

Furtherfeatures and advantages of the invention will become apparentfrom thefollowing description of a specimen embodiment ofthe invention with reference to the drawings, showing essential details of the invention, and from the claims. The individual features may be realized individually or in any desired combination in an embodiment of the invention.

Figure 1 showsthe principle ofthe separation of a staplefroma barofstaples according tothe invention in a sectional representation; Figures2to 5showvarious stages in the sequence of motions of an example of a stapler; Figure 6shows a view, enlarged with respect two Figure 4, in the region ofthe slide; Figure 7shows a section on lineVII-VII in Figure 2.

In Figure 1,a barofstaples 1,with its longitudinal axis in a vertical orientation, is disposed in a device, said device comprising a seating face 2 for the lowermost staple 4. This staple 4 rests on the seating face 2 with its end faces of the joke and of the two legs, said end faces facing away from the bar of remaining staples.

Asupportface 6 supports the outerfaces of the jokes of the staples ofthe bar of staples 1 situated above the staple 4. The correct position of the bar of staples is additionally guaranteed by a cross-sectionally U-shaped guide element 8, whose two sides 12 adjacent to the legs 10 of the staples of the bar of staples 1 extend as far as the seating face 2 and whose part 16 adjacentto the insides of the jokes 14 (orofthe backs) ofthe staplesterminates ata distance above the seating face 2, said distance being very slightly greater than the greatest thickness of the usable staples. The elements 6 and 8 form a magazine into which several bars of staples can be inserted from above.

A slide 20 is moved from the right between the legs 10 ofthe lowermost staple 4 towards the joke 14 of the lowermoststaple4, separating the glued connection between the lowermost staple 4 and the staple directly above it, which is supported during this separating operation on the support face 6. Any torques acting on the lowermost staple 4 during the separating operation have a tendency to press the free ends ofthe legs morefirmly againstthestop face 2, with the result that the correct position ofthe bar of staples 1 is not adversely affected by this operation.

Figure 2 to 5 show merely those parts of a stapling head, in a vertical section, that are important for an understanding ofthe invention. Those parts ofthe stapling head requiredforguidingthevarious moving components are not shown.

The stapling head 30 comprises two slides 31 disposed at a distance from one another. The faces of the two slides 31 facing away from one another and extending parallel to the drawing plane in Figure 2 are a slightlysmallerdistance apartthanthe inside distance between the two legs of the staples. The slides 31 are guided and driven such that they execute a motion extending from right to left and visa versa in Figure 2 to 5. In the views shown in Figure 2 to 5, the slides 31 have basically the shape of a narrow rectangle, with however, the right-hand uppercornerbeing recessed, so that this results (see also Figure 6) in the formation of a supportface 32 extending parallel to the direction of displacement of the slide 31 and in a stop face 33 extending at right anglesto said supportface 32.When shearing off a staple that is still connected to the bar of staples 10, the stop face 33 strikes the joke of the staple from the inside, and the staple, separated from the bar of staples, remains on the supportface 32 and, as the slide moves, is transported by the supportface 32 until thejoke ofthe staple 4 is in a position aligning with a stapling channel 34. The staple is ejected through the stapling channel 34 during stapling.

A ram 36 is guided in such a manner as to be vertically displaceable. The upper end of the ram 36 is intended to be engaged by a driving eiement, shouid it be intended for the stapling head to be operated by machine. The ram 36 is connected by a pin 37 to a vertically displaceable driver 38.

The purpose of the driver 38 is to ejectthe staple 4 through the stapling channel 34 and thus execute the stapling operation. As the ram 36 moves downward, it moves the driver 38 downward. However, in its starting position shown in Figure 2, the driver 38 is still so far away from the staple 4that the distance it has to cover until striking the staple 4 can be used to move downward two reversing rams 40, which are likewise vertically displaceable. During this operation, the rams 40 are in advance of the lower end of the driver 38 and are able, therefore, if, as a result of friction on parts ofthe device, the staple 4 is still in an inclined position, as shown in Figure 2,to swing the legs of the staple 4 downward in a counterclockwise direction aboutthejoke ofthe staple 4, said joke serving as the swivel axis.In doing so, the two reversing rams 40 pass outside the two slides31 andstrikethelegsofthestaple4.

Figure 3 shows the position ofthe device in which the reversing rams 40 have reached their lowermost position, with the faces 42 adjacent to the staple 4 forming a continuation of one ofthe limiting surfaces of the stapling channel 34. In the position shown in Figure 3, the driver38 is just above the joke (or back) of the staple 4.

In the course of its further downward motion, the driver38overtakesthereversing rams40,because the rigidly connected unit of ram 36 and driver38 is connected merely by friction to the reversing rams 40. The friction connection is effected by a spring 44 disposed on the pin 37, said spring pressing afriction plate 46 against the (in the Figures) leftward-pointing face of a holder 43 for the reversing rams 40.

The pin 6 is disposed in a slot 48, so that, when the reversing rams 40 strike a face 50 of a main part 52 of the stapling head, the ram 36 and the driver 38 are able to continue their motion downward, because the above-described slipping clutch slips. During this downward motion of the driver 38, the latter ejectsthe staple 4 downward through the stapling channel 34 and drives itthrough a pile of papers (not shown), with the legs of the staple 4 being bent round by a bottom die disposed below the pile of papers and likewise not shown.

Immediately beforethe driver 38 strikes the joke of the staple 4, the slides 31 are moved to the left. In the position shown in Figure 4, they have been pulled back so farto the left that the staple ofthe bar of staples that is lowermost atthis point in time is able to drop down with its joke and come into contact with the supportface 32 ofthe slide 31. The position in which the driver 38 has reached its lowest position is shown in Figure 4.

When the ram 36 is again moved upward, owing to the above-described friction clutch, it initially takes up with it the reversing rams 40 and the driver 38 until the holder 43 ofthe reversing rams 40 comes up against a fixed stop 55 disposed in the stapling head 30, whereupon its upward motion is terminated. The positions of the individual parts of the device at this point in time are shown in Figure 5. At this point in time, the slides 31 have already separated a further staple on the bar of staples 10 and have covered approximately half the distance to the position shown in Figure 2.

During the further upward motion ofthe ram 36, the driver 38 continues to move upward; the slides 31 continue to move to the right until the position in Figure 2 is reached again.

The above-described sequence of motions ofthe slides 31 is produced by the following driving device for the slides 31, with this driving device being shown merely schematically. Provided atthelower end region ofthe ram 36 is a rightward-projecting projection 60, which bears a hole 62 extending parallel to the direction of displacement of the ram 36, with a rod 64 being displaceably guided in said hole 62. At its upper end,the rod 64 bears a plate 66 acting as a stop. A compression spring 68 in the form of a helical spring is disposed on the rod 64 between the plate 66 and the projection 60. A stop plate 70 is attached on the rod 64 in its region belowthe projection 60.This stop plate 70 meansthatthe rod 64 can slide upwards in relation to the slide 36 only until the stop plate 70 comes up against the projection 60, as is shown in Figure 4. The rod 64 has a stop plate 72 at its lower end, and a sleeve 74 is displaceably guided on the rod 64 above the stop plate62.Acompression spring 76 likewise in the form of a helical spring is disposed between the stop plate 70 and the sleeve 74. A bell crank80 is held on a swivel bearing 82 disposed in the main part 52. In the example, the bell crank is angled ata right angle. One arm 84 has a hinged connection to the sleeve 74 with its free end.

The other arum 86 is connected by its free end to a link 88, which, in turn, is connected to the (Figures) leftward-pointing end ofthe slides 31. Starting from the rest position shown in Figure 2, in which the upper spring 68 is heavily tensioned, with the lower spring 76, on the other hand, being virtually relaxed, during the downward motion of the ram 36, the upperspring 68 is relaxed andthe lowerspring 76is not additionally tensioned up to reaching the position shown in Figure 3. Therefore, the sleeve 74 and the slides 31 retain their positions.During the further downward motion of the ram 36 (Figure 4), the stop plate 70 is moved downward, thereby tensioning the lower spring 76, as a result ofwhich the latter swings the bell crank 80, thereby moving theslides31 back. Duringtheupward motion ofthe ram (Figure 5), the upper spring 68 moves the rod 64 up, with the stop plate 70 remaining up againstthe projection 60 because of the spring 76. The lower plate 72 ofthe rod 68 moves the sleeve 74 and thereforeswingsthe bell crank80 in a counterclockwise direction and slides the slides 31 again to the right. This sequence of motions is continued when, in the course of the further upward motion ofthe ram 36, the position shown in Figure 1 isfinallyagain reached. The hole 62 is sowidethat the rod 64 is ableto pivot in itslightly.

In the rest position, the slides 31 obstruct the way for staples from the magazine, in which the bars of staples 10 are disposed, to the other parts ofthe device.

Possibilities of malfunction are thus precluded.

With the stapling head in this rest position, the single staple 4 held by the slides 31 in Figure 2 is securely held likewise in a defined position and cannot leave its place, because the right-hand limitation ofthe stapling channel 34 extends upward beyond the joke of the staple 4.

During the operation of the device, bars of staples can be inserted into the vertical magazine formed by the guide elements 6 and 8, with the bars of staples sliding downward in the magazine because ofthe force of gravity.

The reference characters in the patent claims do not constitute a limitation, but are intended to facilitate understanding.

Claims (14)

1. Stapling headforthe stapling-togetherof flat-lying piles of paper by means of a U-shaped staple, said staple comprising two legs pointing towards one side and, between said legs, a yoke, with a basically vertically deposed magazine for holding bars of staples with a plurality of parallel deposed and separately connected staples, with a parting device, said parting device acting on the yoke ofthe staple in order to separate a staple from the bar of staples, and with a driver, said driver driving a single staple, having been separated from a bar of staples, through the pile of papers to be stapled, wherein the parting device is guided such that it acts on the yoke from the legs side and wherein the driver (38) is a separate part from the parting device.

2. Stapling head as defined in claim 1 ,wherein the direction of motion ofthe parting device, together with the direction of motion of the driver (38), encloses an angle different from 0" and wherein a device is provided for swinging the staple (4) through the aforementioned angle after it as been separated from the bar of staples (10).

3. Stapling head as defined in claim 2, wherein the angle is approximately 90".

4. Stapling head defined in claim 2 or 3, wherein the device for swinging is of such a design that the joke of the staple forms the swivel axis for the staple.

5. Stapling head as defined in 4, wherein the parting device comprises at least one slide (31), said slide, at the start ofthe separation of the staple from the bar of staples (1 0), contacting with a stop face (33) the inside ofthe joke ofthe staple and embracing with a supportface (32) the free end face ofthejoke of the staple still connected to the bar of staples.

6. Stapling head as defined in any one of claims 2 to 5, wherein the device for swinging the staple comprises a reversing ram (40),said reversing ram being displaceably guided basically parallel to the direction of displacement ofthe driver (38) and, after the swinging of the staple, forming a guide forthe stapleto be moved bythedriver.

7. Stapling head as defined in any one ofthe preceding claims, wherein a driving device for a slide (31) ofthe parting device is of such a design that the slide (31) is out of engagement with the staple after the device for swinging has swung the staple.

8. Stapling head as defined in any one ofthe preceding claims, wherein a driving device for a slide (31) ofthe parting device is provided, said driving device bringing said slide out of engagement with the staple before the driver (38) moves the staple.

9. Stapling head as defined in claim 8, wherein the driving device comprises at least one spring (68, 76), said spring being connected to the driver (38) of the stapling head.

10. Stapling head as defined in 6, wherein the driver (38) is connected byfriction to the reversing ram (40).

11. Stapling head for the stapling-together of flat-lying piles of paper by means of a U-shaped staple, said staple comprising two legs pointing towards one side and, between said legs, a joke, with a basically vertically disposed magazine for holding bars of staples with a plurality of parallel disposed and separable staples, with a parting device, said parting device acting on the joke of the staple in order to separate a staple from the bar of staples, and with a driver, said driver driving a single staple, having being separated from a bar of staples, through the pile of papers to be stapled, wherein the parting device is guided such that it acts on the joke from the legs side, and wherein the driver (38) is a separate part from the parting device, and wherein the parting device comprises at least one slide (31), said slide, at the start of separation of the staples from the bar of staples (10), contacting with a stop face (33) the inside of the joke of the staple and embracing with a support face (32) the free end face of the joke of the staple still connected to the bar of staples, said embracing taking place from the side of the staple facing away from the bar of remaining staples, and wherein the slide is driven such that, afterthestaple has been separated from the bar of remaining staples, it moves the staple until the joke ofthe staple is in a position aligning with a stapling channel (34), the stapling channel (34) being intended to guidethe staple as it is being ejected by the driver (38), and wherein a reversing ram (40) is connected byfriction to the driver (38), said reversing ram being displaceably guided basically parallel to the direction of displacement of the driver (38) and, as the driver (38) moves towards the staple, striking the staple before the driver (38) and swinging the staple and, afterthe staple has been swung, forming aguideforthestapleto be moved by the driver, and wherein the driving device forthe slide (31) is of such a design that it brings said slide out of engagement with the staple before the driver (38) moves the staple, and wherein a driving device for the slide (31) comprises a rod (64) on which are disposed two compression springs (68,76), a stop plate (70) being attached to the rod between said compression springs, and wherein the rod (64) is guided on a vertically displaceably guided ram (36) such as to be displaceable basically in parallel mannerto the latter, and wherein a fixed bell crank (80) is connected by one end to a sleeve (74), said sleeve being displaceably disposed on the lower end of the rod (64), and wherein the other end of the bell crank is connected to the slide (31) through the intermediary of a link(88).

12. Stapling head as defined in any one of the preceding claims, wherein the free end face of a staple still connected to a bar of staples is, when in its position for being separated from the bar of staples, in contact with a face of a magnef.

13. Stapling head substantially as described with reference to the attached drawings.

14. Stapling apparatus comprising a magazine for holding a stack of staples, a device for parting a staple from the stack, and a driver for driving the parted staple into a workpiece such as a plurality of sheets of paper, the driver being separate from the parting device.