US2754958A

US2754958A - Stapling mechanism

Info

Publication number: US2754958A
Application number: US386888A
Authority: US
Inventors: Murrell John Thomas; Turrall George
Original assignee: Crabtree & Sons Ltd R
Current assignee: RW Crabtree and Sons Ltd
Priority date: 1953-10-19
Filing date: 1953-10-19
Publication date: 1956-07-17
Anticipated expiration: 1973-07-17

Description

y 1956 J. T. MURRELL ET AL 2,754,958

STAPLING MECHANISM 2 Sheets-Sheet 1 Filed Oct. 19, 1953 July 17, 1956 J. T. MURRELL ETAL 2,754,958

STAPLING MECHANISM Filed Oct. 19, 1953 2 Sheets-Sheet 2 3 900) it-w I I M Q 12 F/G.5. 3 g

Inventors /hflmaamll' WWW STAPLING MECHANISM John Thomas Murrell, Barking, and George Turrall, Wandsworth Common, England, assignors to R. W. Crabh'ee & Sons Limited Application October 19, 1953, Serial No. 386,888

'12 Claims. (Cl. 203-65) This invention relates to stapling mechanism of the kind which is employed in printing, box-making and other machines for the purpose of stapling together a number of webs or sheets of papers, card or similar material to form the product of the machine.

In such machines the staples are formed as they are about to be inserted for which purpose wire is fed from a supply spool to a device which cuts lengths of stapleforming wire, forms the staples and inserts them.

The demand for the wire is such that it is frequently necessary in the course of a production run to replenish the wire supply and this involves stopping the machine while wire from a new spool is applied to the wire feeding device: the wire employed is of small diameter and the introduction of the leading end of the wire from the new spool is not alway easy so that the change-over to a new spool takes some time and causes a loss in production. In addition, an operator has to watch the spool in use so as to make the necessary change when the spool is about to become exhausted and, to avoid the possibility of the wire supply running out before the wire supply has been replenished, the operator is compelled to make the change before the spool has become completely exhausted so that some wastage of wire occurs.

The main object of this invention is to provide a wirefeed mechanism which will enable the wire feed to the staple cutting, forming and inserting device (hereinafter referred to as the staple forming device) to be continuously maintained from a number of spools without the necessity for stopping the wire-consuming machine.

Broadly stated the present invention consists in providing a wire-feed mechanism which is arranged to detect when the supply of wire from one spool or other source of supply is about to be exhausted and to operate thereupon automatically to take the leading end of wire from another spool to maintain the feed of wire to the staple forming mechanism.

The detection can be provided by passing the wire from a spool in use between two components which are held apart so long as wire is present between them but which move together when the end of the wire arrives, the resulting relative movement of the components causing the leading end of wire from a fresh spool to be taken and fed forward to the staple forming device. The two detecting components can be constituted by feed rolls which are driven to feed the wire to the staple forming device, and in such a case, when the wire passes out of the nip of the rolls, another pair of rolls is caused to nip the leading end of the fresh wire and advance it to the feed rolls.

A preferred form of construction is shown in the accompanying drawings in which Figure 1 is a plan view, Figure 2 a section on the line II-II, Fig. l, and Fig. 3 a side elevation of a wire feed unit. Figs. 4 and 5 are diagrammatic views showing the manner of operation of a device according to this invention.

Referring to the drawings the mechanism shown is intended to advance continuously staple forming wire Hired Sta Pam: Q

Patented July 17, 1956 "ice W from a supply spool so that lengths can be successively sheared from its projecting end by a cutter, the sheared length being taken by a stapling machine which forms the length of wire into a staple and forces the staple through sheets or plies to be stapled together: the mechanism is arranged to enable the wire when it is exhausted to be replaced automatically by another wire.

To effect this two pairs of

feed rolls

1, 2 and 3, 4 are provided: the

rolls

1, 3 of the two pairs are carried by a fixed frame 5 while the

rolls

2 and 4 are carried by a frame 6 mounted on a pivot pin 7 on the fixed frame 5.

The frame 6 is urged to rock on the pivot by springs 8, which are so arranged with respect to the pivot pin as to afford a bias urging the

rolls

2, 4 towards the

rolls

1 and 3. The

rolls

3 and 4 have a slightly greater distance between their centres of rotation than the

rolls

1, 2 so that so long as wire (indicated at W) is located between the primary rolls, 1, 2 those rolls alone grip and advance the wire, the wire passing freely between the

secondary rolls

3, 4.

The fixed frame 5 is formed with two converging

wire guides

9, 10 for wire drawn from two separate spools A, B; the two guides converge into a single guide 11 at a point between the

primary rolls

1, 2 and the

secondary rolls

3, 4, all the guides cutting into the nip between the I, two pairs of rolls.

So long as wire passing through one guide, say the guide 9, from one spool B is present between the

primary rolls

1, 2 wire drawn from the other spool A can be introduced through the other guide 10 between the see- I

ondary rolls

3, 4 up to the point of convergence.

' When the end of the wire from the spool B in use passes out of the nip of the

primary rolls

1, 2, the pivoted frame 6 is allowed to rock to carry the pairs of rolls towards one another: the

secondary rolls

3, 4 are now able. to bite upon and advance the wire from the other spool A to the nip of the

primary rolls

1, 2 which then maintain p the fresh spool A is itself exhausted.

The action will be clearly seen from Figs. 4 and 5: Fig. 4 shows the setting of the parts when the wire in use (indicated at W1) is being fed by the

primary rolls

1, 2 but is about to expire; Fig. 5 shows the setting of the parts when the expiring wire W1 has passed out of the nip of the

primary rolls

1, 2 and the replenishing wire (indicated at W2) is being fed forward by the

secondary rolls

3, 4 to the nip of the

primary rolls

1, 2.

The point at which the two

guides

9, 10 converge would be arranged as closely as possible to the nip between the

primary rolls

1, 2 so that, the trailing end of the wire W1, which is about to be replenished, will be followed very closely by the leading end of the fresh Wire W2: the

secondary rolls

3, 4 will thus advance the replenishing wire only a very small distance from the point of convergence to the nip of the

primary rolls

1, 2; the leading end of the fresh wire W2 having passed into the nip of the

primary rolls

1, 2 will then engage the trailing end of the replenished wire W1 and advance it to the staple forming mechanism so that no wastage of wire occurs.

The axes of rotation of the rolls 1-4 can be fixed at the centres necessary to hold the

rolls

3, 4 at a slightly greater separation than the rolls 1, 2: it is however preferred to arrange for adjustment of the distances of one or other pair of rolls: as shown, this is effected by mounting the spindle 12 carrying the roll 3 of the secondary pair in an eccentric bush 13 having an adjusting flange 14 receiving a locking screw 15.

Drive to the rolls is effected through a gear 16' on the spindle 16 of the primary roll 1, this spindle having a gear 17 which transmits drive through an intermediate gear 18 to a gear 19 on the spindle 12 of the secondary roll 3: the gear 17 also meshes with a gear 20 on the other primary roll 2 and the gear 19 meshes with a gear 21 on the other secondary roll 4 so that all the rollers are driven in unison.

For the purpose of enabling the pivoted frame 6 to be moved by hand to separate the pairs of rolls when initially threading wire into position, the frame 6 is provided with an arm 22 and a screw 23 is provided to limit adjustably the approach of the rolls under the action of the springs 8.

Reference will again be made to Fig. 1 which shows one application of a wire feed mechanism according to this invention, the application being to a stapling mechanism according to the invention described in the specification of the pending application Ser. No. 328,578 and now Patent No. 2,709,808.

That stapling mechanism employs a staple forming cylinder 24 which as it rotates operates a cutter 2S disposed to sever a staple-forming length of wire, this length being taken by beaks 26 disposed on the periphery of the cylinder about a staple-forming recess 27 in the cylinder: cooperating with this recess is a punch which is fixed to a punch cylinder so that as the cylinders rotate the punch runs into and out of the recess 27 and in so doing forces the cut length of wire into the recess to form a staple indicated at S. In such an application the cutter 24 will be disposed to shear oif the requisite length of wire from the end of the wire as it is advanced out of the guide 11 by the action of the feed rolls as has been described.

It will be obvious that an arrangement according to this invention enables an operator at any time while wire is being drawn from a spool, to dispose the leading end of fresh wire from another spool in a position ready to be taken when the first expires: the operator is thus afforded ample time to carry out this operation and is relieved of the necessity for observing when the supply of wire should be transferred to a new spool: these ad vantages are obtained in addition to the avoidance of stopping the machine.

What we claim is:

1. For use with a continuously acting wire-consuming stapling machine, a wire-feeding mechanism comprising a pair of wire-advancing devices to receive respectively the leading ends of a wire supply from two different sources, and means controlled by the presence of wire at one of the advancing devices automatically to hold the other advancing device inactive and to render the other advancing device active to advance wire as the trailing end of the wire being fed passes the said one being fed by the feeding device passes said feeding device whereby an automatic continuous feed of wire is effected.

3. For use with a wire-consuming stapling mechanism, a wire feed mechanism comprising driven feed rolls biased to move relatively towards one another, means mounting said feed rolls for relative movement towards and away from one another, means to advance wire taken from one of two sources of supply to a position between the feed rolls to hold them apart, and means mounting said advancing means and operatively connecting said advancing means to said feed rolls for movement with said feed rolls, the presence of wire between said feed rolls maintaining them relatively apart against their bias and rendering said advancing means inactive, the passage of the trailing end of said wire from between said feed rolls permitting said feed rolls to move relatively towards one another under the influence of their bias and rendering said advancing means active to advance wire from the other source of supply to a position between the feed rolls.

4. A wire-feed mechanism as claimed in claim 3 and wherein the advancing means comprises a second pair of driven rolls having a greater separation than the feed rolls, the wire from both sources of supply being passed between the rolls of the second pair, which rolls are relatively movable towards and away from one another in unison with the corresponding movement of the feed rolls.

5. A wire feed mechanism as claimed in claim 4 and wherein one of the rolls of each pair is carried by a first support and the other rolls are carried by a second support movable relatively to the first support and being urged to carry the rolls toward one another.

6. A wire feed mechanism as claimed in claim 5 and wherein the second support is pivotally carried by the first. 7. A wire feed mechanism as claimed in claim 6 and having separate converging guides to direct wire from the two sources of supply between the rolls of the second pair, the guides converging to a single delivery guide.

8. A wire feed mechanism as claimed in claim 7 wherein the converging guides are arranged to converge into the single delivery guide at a zone between the first and second pairs of rolls.

9. A wire feed mechanism as claimed in claim 4 and having separate converging guides to direct wire from the two sources of supply between the rolls of the second pair, the guides converging to a single delivery guide.

10. A wire feed mechanism as claimed in claim 9 and wherein the converging guides are arranged to converge into the single delivery guide at a zone between the first and second pairs of rolls.

11. A wire feed mechanism as claimed in claim 5 and having separate converging guides to direct wire from the two sources of supply between the rolls of the second pair, the guides converging to a single delivery guide.

12. A wire feed mechanism as claimed in claim 1 l and wherein the converging guides are arranged to converge into the single delivery guide at a zone between the first and second pairs of rolls.

References Cited in the file of this patent UNITED STATES PATENTS 2,351,111 Davis June 13, 1944 2,613,706 Smith Oct. 14, 1952 2,640,654 Schweiter June 2, 1953