US2264798A - Typographical machine - Google Patents

Description

Dec. 2, 1941; J. H. HILPMAN 2,264,798

TYPOGRAPHICAL MACHINE Filed Nov. 13, 1940 2 Sheets-Sheet 1 J BY 26%, INVEAITOR J. H. HILPMAN v 2,264,798

TYPOGRAPHICAL MACHINE Dec. 2, 1941.

Filed Nov. 15, 1940 2 Sheets-Sheet 2 zlimmm INVENTOH ATTO EYJ Patented Dec. 2, 1941 TYPOGRAPHICAL MACHINE John H. Hilpman, Springfield Gardens, N. Y., as-

signor to Mergenthal'er Linotype Company, a corporation of New York Application November 13, 194%), Serial No. 365,425

FiQE,

24 Claims.

This invention relates to typographical machines, such as Linotype machines of the general organization represented in U. S. Letters Patent to O. Mergenthaler No. 436,532, wherein circu- 1G. The metal pot advances and pushes the mold forward against the line of matrices, pressing the matrices back for facewise alignment.

11. The metal pot recedes, relieving the matrix lating matrices are released from a magazine in 5 line from the pressure of the mold.

the order in which their characters are to appear 12. The vise closing lever rises, allowing the in print and then composed in line, the comwedge sp ng o aise e W d o its p p posed line transferred to a mold where it is justiheight and move the left-hand jaw inward to the fied, the mold filled with molten metal to form exact length of the line.

a slug or Linotype against the matrices which The luStifiCatiOn d V Closing eV produce the type characters thereon, and the rise simultaneously, causing the justification bar matrices thereafter elevated and returned to rise O ta d p t spfi s pthrough a distributing mechanism to the magaward through the in of atri s to complete th zine from which they started. j s fi In these machines, after the matrices have The metal p Closes against the mold, been composed in line, the assembler elevator is forcing the mold against the line of justified matraised by hand between the fingers of the line r1095, ma n t 1 delivery carriage and trips a latch which permits The p lever descends and the p the carriage to transfer the composed line to plunger delivers metal into he m d fro the the first elevator and to inaugurate the operation metal pot to form the slug, after which the of the driving mechanism for the main cam D p plunger rises ga shaft. The following actions then take place: T up d p e n t e fi st vato 1. The first elevator de cend t present th due to action 9, is relieved, thereby relieving the composed line i front f the m m During thi lower matrix ears from further strain. The jusaction, the first-justification lever also descends. tification lever d vise closing v r d nd.

2. The left-hand vise ja i dosed, making t relieving the pressure on the line, and the metal distance between the vise jaws a little less than p and he mold slide then move backward, the proper length f the line befgre t tt drawing the face of the slug out of the matrices. descends b twee th 17. The mold slide stops and the pot continues 3. During actions 1 and 2, the mold disc makes to at. s a ti e ou o t e not f om a one-quarter rotation to carry the active mold the base of thelslllg. from the vertical or ejecting position to the hori- The mold disc makes a three-quarter ro azontal or casting position, tion, carrying the base of the slug in the mold 4 Th mold id carrying t mold disc, past the back knife, thereby trimming the base of moves forward, leaving about one-hundredth of 5 t Slug t0 the proper height, n finally o s an i h pace b t th 1 jaws and t to rest with the slug in avertical position in front matrices, one the one hand, and the face of the 0f t t O im knives ready to be j fi e m ld, o th ther h d from the mold. During this action, the first ele- 5. The vise closing lever rises, allowing the Vatol rises, lifting the matriX line 0 the upp vise jaw wedge spring to raise the Wedge and 40 transfer channel, where it is transferred to the move the left-hand jaw outward to leave the second elevator. proper distance between the vise jaws after the The pp transfer Carriage new oves the composed l h b justified matrix line onto the second elevator. The car- 6. The justification levers rise, causing the jusriage slide and the spaceband pawl move back, tifica'tion bar to rise in an inclined position and allowing the second elevator to lift the matrices push the spacebands successively upward through out of the transfer channel while leaving the the line. This is called the first justification. spacebands therein. The carriage slide and the During actions 2 to 6, the line delivery carriage spaceband pawl next move toward each other, returns to its original position, ready to receive pushing the spacebands together and then rethe next line from the assembler elevator. '50 storing them to the spaceband box.

'7. The justification levers descend, relieving 20. The ejector blade moves forward and the spacebands from the upward justifying pres pushes the slug out of the mold between the sure. trimming knives and into the galley at the front 8. The vise closing lever descends, relieving the of the machine. I i vise jaw pressure to allow the vertical alignment 21. During operation 20, the first elevator is of the matrices. lowered to its normal position ready to receive 9. The first elevator rises, lifting the matrices another line. At the same time the second to bring their lower ears into engagement with elevator rises to register with the bar in the disthe aligning shoulders on the mold for the vertitributor box. cal alignment. to 22. While the second elevator is rising, the

distributor shifter is moved outward to be in position to shift the line into the distributor box. 23. The distributor shifter moves inward, pushing the line into the distributor box. At the same time the justification lever rises slightly and actuates the slug stacking lever to assemble the slugs in the galley. At the same time the ejector retreats to its normal position of rest.

This completes the actions of the various organs of the machine for one complete rotation of the main cam shaft.

In controlling these different actions of the various organs, the cams on the main shaft are required to move the organs at least positively in one direction and in many instances positively in both directions. Consequently, if the positive movement of any of the different organs is prevented or unduly resisted, the parts are apt to become overstrained or badly damaged, not to mention other diificulties which may arise as a result of the abnormal operation. For this reason, it has heretofore been proposed to provide safety devices which will act automatically to arrest the operation of the main cam shaft in the event that undue resistance is offered to the movement of some particular organ of the machine. Thus, it has been proposed to provide such a safety device for the mold slide whose forward movement is frequently prevented by the failure of the bushings on the mold disc to align with the locating studs on the vise frame and whose forward movement is also frequently prevented by contact of the active mold with an improperly located matrix line (see for example Sperry Patents Nos. 1,674,415 and 1,780,848). Again, it has been proposed to provide such a safety device for the metal pot whose forward movement is frequently prevented, either because of the failure of the mold disc to go forward its proper distance or for other reasons (see Watson Patent No. 2,195,140). As another example, such a safety device has been provided for the ejector whose forward movement is frequently prevented by a mold liner of improper length (see Fadum Patent No. 1,475,007). These prior safety attachments are rather complicated and expensive and, moreover, are limited in their action to one particular organ of the machine. To provide a separate safety device for each organ of the machine (assuming that could be done) would be tremendously expensive and lead to many complications so that, notwithstanding the need for them, no safety devices have been provided for many of the organs of the machine subject to abnormal operation.

The present invention is intended to provide a safety device which will be effective as to all of the various organs of the machine, thus avoiding any necessity of duplication, as heretofore, in respect to particular organs whose abnormal operation is apt to lead to the most severe damage, and providing a safeguard against damage which might arise from the abnormal operation of those organs which do not lend themselves readily to the use of individual safety devices. To this end, specifically, it is proposed to alter the driving mechanism for the main cam shaft in such manner that an overload of the driving mechanism, as caused by abnormal resistance to rotation of said shaft, will arrest 7 the operation of the driving mechanism and thus avoid overstrain or damage to the parts. In the embodiment illustrated, this is accomplished by mounting the driving gear on the drive shaft so that it may yield with reference thereto whenever an overload occurs, and by providing means actuated by such yielding of the driving gear to disengage the regular driving clutch. Such modification of the driving mechanism has been made in a simple and inexpensive manner, as will later be seen, and moreover without interfering with the operation of the clutch in the regular way in starting and stopping the ope ation of the driving mechanism for a given machine cycle. In other words, the improved driv- 'ing mechanism will be started and stopped in the usual way under normal operating cpnditions of the main cam shaft for the regular machine cycle but will be arrested during the machine cycle whenever it is subjected to an overload due to abnormal resistance to rotation of the main cam shaft as produced by the abnormal operation of any one of the various organs of the machine controlled from that shaft.

Referring to the drawings:

Fig. 1 is an end elevation of the main cam shaft of a Linotype machine and showing some of the organs of the machine controlled therefrom;

Fig. 2 is a vertical section taken through the main cam shaft in the region of the driving gear therefor;

Fig. 3 is a horizontal section taken on the line 3--3 of Fig. 2 looking downwardly or in the direction of the arrows in that figure;

Fig. 4 is an enlarged elevation, partly in section, of the drive shaft, showing by the full lines the normal position of the driving gear with respect thereto and by the dotted lines the displaced position of the driving gear due to an overload of the driving mechanism; and

Fig. 5 is a vertical longitudinal section taken on the line 55 of Fig. 2 through a portion of the drive shaft.

Fig. 1 shows a few, but only a few, of the various organs of the machine controlled from the main shaft. For identification these organs are: the mold disc A with its driving pinion A drive shaft A and the driven pinion A which latter is arranged to be engaged by gear segments on one of the cams of the main shaft l; the swinging metal pot B with its operating lever B, which latter is actuated by the cam 2 on the main shaft; the pot plunger C with its actuating lever C which latter is arranged to be operated by the cam 3 on the main shaft; the wedge bar D with the vise closing lever D which latter is arranged to be operated by a cam (not shown) on the main shaft; the first elevator actuating lever E (the elevator not shown) arranged to be operated by the cam 4 on the main shaft; the second elevator actuating lever F (the elevator not shown) arranged to be actuated by a cam (not shown) on the main shaft; and the distributor shifter actuating lever G (the shifter not shown) arranged to be operated by a cam (not shown) on the main shaft. To complete the description of the main shaft, it is enough to say that it is also provided with a large gear 5 meshing with n the driving gear of the driving mechanism.

The driving mechanism will now be described: The main driving pulley 6 is mounted to turn freely on the drive shaft 1, the pulley being formed with a gear ring 8 meshing with the small pinion 9 (shown in dotted lines in Fig. 2) of the drive shaft of an electric motor or other prime mover. The pulley 6 has an internal clutch face to co-operate with the friction clutch shoes I0 movably connected to a clutch member ll keyed or otherwise fixed to the drive shaft 1.

The. clutch shoes are connected to operating links 12, which in turn are operatively connected to an actuating head l3 on the outer end of a rod or spindle l4 slidable axially through a bushing l 5 in the outer end of the shaft 7, which latter is bored out or made hollow to contain the rod. At its inner end the rod I4 is pinned to a sliding clutch actuating sleeve I6 (see Fig. 3) which is mounted to slide axially on the shaft 7. A compression spring ll, reacting against the bushing l5, and a collar l8 pinned to the rod, tends to set the clutch in driving condition and to maintain it in such condition.

The clutch is controlled by a bell crank lever pivoted at I9 in the fixed machine frame, one arm of which lever bears against the clutch operating sleeve l6, and the other arm 2| of which has a pin 22 which engages in the forked end of a fore-and-aft starting and stopping bar 23. The drive shaft 1 is journalled in a bearing 24 of the fixed machine frame, being held against endwise movement in the bearing by means of a key 25 (see Fig. 5) engaging in an annular groove 26 formed in the external surface of the drive shaft.

So far as described, the parts of the driving mechanism and the mode of operation are or may be substantially the same as embodied in the commercial Linotype machines or as shown and described in the Rogers Patent No. 661,386 to which reference may be had if desired. As well understood, the starting and stopping of the driving mechanism is effected by the engagement and disengagement of the clutch through the bell crank lever 20, 2|, sleeve [6, and actuating rod l4. Normally, the rod [4 will be held to the left in Fig. 3 to maintain the clutch disengaged against the opposition of the spring H, but when the line delivery carriage delivers the composed line into the first elevator, that carriage, through a swinging dog carried by one of the cams on the main shaft, trips the rod l4 and allows the spring I! to move the rod to the right in Fig. 3 and bring about the engagement of the clutch. Under normal operating conditions, the clutch will remain engaged until the main cam shaft makes one complete rotation, whereupon through the same dog just referred to the rod I4 is again shifted to the left against the action of the spring I? to disengage the clutch and bring the parts to rest.

Coming new to the present invention: Heretofore the driving gear 21, which meshes with the large gear 5 on the main shaft, has been made fast with the drive shaft 1. In the present instance, however, and for the reasons previously stated, the driving gear is mounted to yield with reference to the drive shaft whenever there is an overload of the driving mechanism caused by abnormal resistance to rotation of the main cam shaft during the machine cycle. To this end, the driving gear is fixed to a second rod 28 fitted in the right end of the drive shaft 1, which has been bored out for the purpose, and journalled beyond the driving gear in an outboard bearing 29 of the fixed machine frame. As clearly shown in Figs. 3 and 4, the rod 28 is provided with an inclined key 30 attached thereto by a cap screw 3| and arranged in a correspondingly inclined keyway 32 formed in the shaft 7, it being noted that the keyway is made slightly longer than the key to permit the driving gear 2! and its mounting rod 28 to partake of a slight relative rotation with respect to the drive shaft 1 (see dotted lines in Fig. 4). Due to the inclination of the key and keyway, the gear mounting rod 28, in partaking of such relative rotation, will move endwise to the left in Figs. 3 and 4 or in the direction of the clutch disengaging movement of the rod l4, and this motion is transmitted to the .rod I4 to disengage the clutch by providing the rod 28 with a reduced extension 33 which is arranged in end-abutting relation to the rod 14. Under normal conditions, however, the rod 28 is held to the right, with the driving gear 2.? in normal driving position, by a compression spring 34 encircling the reduced extension 33 and reacting against an annular shoulder 35 presented within the shaft 1 by the bore which accommodates the rod. It will be seen, therefore, that the presence of the gear mounting rod 28 within the drive shaft 1 in no wise interferes with the engagement and disengagement of the clutch under normal operating conditions, the clutch actuating rod M being free to move independently of the rod 28. However, when the clutch is engaged to carry out the regular machine cycle, the rod l4 makes contact with the extension 33 of the rod 23 so that, whenever the latter is caused to yield to the left against the action of the spring 34, due to an overloadof the driving mechanism during the machine cycle, the rod It will be shifted to the left to disengage the clutch. In effecting such disengagement of the clutch, the rod 28 will, of course, overcom the combined opposition of its own spring 34 and the clutch actuating spring ll. It is this combined power of the two springs which maintains the driving gear 21 in its normal driving position, that is to say, with the key 30 of the rod 28 at that end of the keyway 32 leading in the direction of rotation, the key and slot exerting a cam effect to maintain the driving gear in that normal position. The tension of the springs can be adjusted to suit conditions by the bushing l5, as well as by the small turn buckle 36 arranged between the abutting end of the two rods. It may be explained that while the normal load on the driving mechanism might seem greater than could be taken care of by the arrangement described, the fact is that this is not so, for the reason that the resistance to rotation of the cam shaft, even when several of the different organs are being operated at the same time, imposes a comparatively light load on the driving mechanism, due to the shape of the cams and the leverage which favors them in operating the machine organs. It is therefore one of the advantageous features of the present arrangement that an overload of the driving mechanism which brings about the disengagement of the clutch will never be so excessive as to cause overstraining or damage to the parts.

It may be explained that when the driving clutch is disengaged during the machine cycle by an overload of the driving mechanism, the driving gear 21 remains in mesh with the driven gear 5 on the main cam shaft, so that upon the release of the overload by remedying the condition which caused it, the driving clutch will be automatically reengaged and the rotation of the main cam shaft continued until the machine cycle is completed.

In the accompanying drawings, the invention has been shown merely in preferred form and by way of example, but obviously many variations and modifications may be made therein which will still be comprised within its spirit. It is to be understood, therefore, that the invention is not limited to any specific form or embodiment,

except insofar as such limitations are specified in the appended claims.

Having thus described my invention, what I claim is:

1. In or for a typographical machine equipped with a rotary cam controlling the operation of one of the movable organs of the machine, driving mechanism for rotating the cam and comprising means distinct from the operating connections between the cam and said movable organ actuated automatically by an overload of the driving mechanism, as caused by abnormal resistance to rotation of the cam, to arrest the operation of the driving mechanism.

2. In or for a typographical machine equipped with a rotary cam controlling the operation of one of the movable organs of the machine, driving mechanism comprising a clutch through which the cam is rotated, and automatic means distinct from the operating connections between the cam and said movable organ actuated by an overload of the driving mechanism, as caused by abnormal resistance to rotation of the cam, to disengage the clutch.

3. In or for a typographical machine equipped with a rotary cam controlling the operation of one of the movable organs of the machine, driving mechanism for rotating the cam and comprising a driving gear displaceable from its normal driving position in the event of an overload due to abnormal resistance to rotation of the cam, and means actuated by such displacement of the driving gear for arresting the operation of the driving mechanism.

4. In or for a typographical machine equipped I 5. In or for a typographical machine equipped '3;

with a series of rotary cams controlling the operation of various movable organs of the machine, common driving mechanism for rotating said cams and comprising means distinct from the operating connections between the cams and {,5

their respective movable organs actuated automatically by an overload of the driving mechanism, as caused by the abnormal resistance to rotation of any one of the cams of the series, to

arrest the operation of the driving mechanism.

6. In or for a typographical machine equipped with a series of rotary cams controlling the operation of various movable organs of the machine, common driving mechanism comprising a clutch through which the cams are rotated, and means distinct from the operating connections between the cams and their respective movable organs actuated automatically by an overload of the driving mechanism, as caused by abnormal resistance to rotation of any one of the cams of the series, to disengage the clutch.

'I. In or for a typographical machine equipped with a series of rotary cams controlling the operation of various movable organs of the machine, common driving mechanism for rotating said cams and comprising a driving gear displaceable from its normal driving position in the event of an overload due to abnormal resistance to rotation of any one of the cams of the series, and means actuated by such displacement of the driving gear for arresting the operation of the driving mechanism.

8. In or for a typographical machine equipped with a series of rotary cams controlling the operation of various movable organs of the machine, common driving mechanism comprising a clutch through which the cams are rotated, a driving gear displaceable from its normal driving position in the event of an overload due to abnormal resistance to rotation of any one of the cams of the series, and means actuated by such displacement of the driving gear to disengage the clutch.

9. In or for a typographical machine equipped with a rotary main shaft provided with a series of cams controlling the operation of various movable organs of the machine, driving mechanism for rotating said shaft and comprising means distinct from the operating connections between the cams and their respective movable organs actuated automatically by an overload of the driving mechanism, as caused by abnormal resistance to rotation of said shaft, to arrest the operation of the driving mechanism.

10. In or for a typographical machine equipped with a rotary main shaft provided with a series of cams controlling the operation of various movable organs of the machine, driving mechanism comprising a clutch through which said shaft is rotated, and means distinct from the operating connections between the cams and their respective movable organs actuated automatically by an overload of the driving mechanism, as caused by abnormal resistance to rotation of said shaft, to disengage the clutch.

11. In or for a typographical machine equipped with a rotary main shaft provided with a series of cams controlling the operation of various movable organs of the machine, driving mechanism comprising a clutch through which said shaft is rotated, a driving gear yieldable with reference to the drive shaft in the event of an overload caused by abnormal resistance to rotation of the main cam shaft, and means actuated by such yielding of the driving gear to disengage the clutch.

12. In or for a typographical machine equipped with a rotary main shaft provided with a series of cams controlling the operation of various movable organs of the machine, driving mechanism comprising a clutch through which said shaft is rotated, a driving gear mounted to yield axially on the drive shaft in the event of an overload caused by abnormal resistance to rotation of the main cam shaft, and means actuated by such axial movement of the driving gear to disengage the clutch.

13. In or for a typographical machine equipped with a rotary main shaft provided with a series of cams controlling the operation of various organs of the machine, driving mechanism for said shaft comprising a hollow drive shaft, a driving pulley loosely mounted on said drive shaft, a clutch fixed to said drive shaft and movable into and out of driving engagement with the driving pulley, a spring actuated axially movable rod contained within the hollow drive shaft and connected to the clutch, a second spring actuated axially movable rod contained within the hollow drive shaft and arranged in end-abutting relation to the first rod, said second rod being connected by an inclined key and slot connection with the drive shaft so as to partake of a limited rotation and endwise movement with reference thereto, and a driving gear fixed to the second rod; whereby an overload of the driving mechanism, as

caused by abnormal resistance to rotation of the main cam shaft, will bring about the disengagement of the clutch from the driving pulley.

14. In or for a typographical machine equipped with a rotary cam controlling the operation of one of the movable organs of the machine, driving mechanism for rotating said cam, means operable to start and stop the operation of said driving mechanism to rotate the cam under normal operating conditions for a given machine cycle, and means distinct from the operating connections between the cam and said movable organ actuated automatically by an overload of the driving mechanism, as caused by abnormal resistance to rotation of the cam during the machine cycle, to arrest the operation of the driving mechanism.

15. In or for a typographical machine equipped with a series of rotary cams controlling the operation of various movable organs of the machine, common driving mechanism for rotating said cams, means operable to start and stop the operation of the said driving mechanism to rotate the cams under normal operating conditions for a given machine cycle, and means distinct from the operating connections between the cams and their respective movable organs actuated automatically by an overload of the driving mechanism, as caused by abnormal resistance to rotation of any one of the cams of the series during the machine cycle, to arrest the operation of the driving mechanism.

16. In or for a typographical machine equipped with a rotary cam controlling the operation of one of the movable organs of the machine, driving mechanism comprising a clutch through which said cam is rotated, means operable to engage and disengage the clutch in starting and stopping the operation of the driving mechanism under normal operating conditions for a given machine cycle, and means distinct from the operating connections between the cam and said movable organ actuated automatically by an overload of the driving mechanism, as caused by abnormal resistance to rotation of the cam during the machine cycle, to disengage the clutch.

17. In or for a typographical machine equipped with a series of rotary cams controlling the operation of various movable organs of the machine, common driving mechanism comprising a clutch through which the cams are rotated, means to engage and disengage the clutch in starting and stopping the operation of the driving mechanism under normal operating conditions for a given machine cycle, and means distinct from the operating connections between the cams and their respective movable organs actuated automatically by an overload of the driving mechanism, as caused by abnormal resistance to rotation of any one of the cams of the series during the machine cycle, to disengage the clutch.

18. In or for a typographical machine equipped with a rotary main shaft provided with a series of cams controlling the operation of various movable organs of the machine, driving mechanism for rotating said shaft, means operable to start and stop the operation of the driving mechanism under normal operating conditions for a given machine cycle, and means distinct from the operating connections between the cams and their respective movable organs actuated automatically by an overload of the driving mechanism, as caused by abnormal resistance to rotation of the main cam shaft during the machine cycle, to arrest the operation of the driving mechanism.

19. In or for a typographical machine equipped with a rotary main shaft provided with a series of cams controlling the operation of various movable organs of the machine, driving mechanism comprising a clutch through which said shaft is rotated, means operable to engage and disengage the clutch in starting and stopping the operation of the driving mechanism under normal operating conditions for a given machine cycle, and means distinct from the operating connections between the cams and their respective movable organs actuated automatically by an overload of the driving mechanism, as caused by abnormal resist ance to rotation of the main cam shaft during the machine cycle, to disengage the clutch.

20. In or for a typographical machine equipped with a rotary main shaft provided with a series of cams controlling the operation of various move able organs of the machine, driving mechanism comprising a clutch and a driving gear through which said shaft is rotated, means to engage and disengage the clutch in starting and stopping the operation of the driving mechanism under normal operating conditions for a given machine cycle, said driving gear being mounted for displacement from its normal driving position in the event of an overload due to abnormal resistance to rotation of the main cam shaft during the machine cycle, and means actuated by such displacement of the driving gear to disengage the clutch.

21. In or for a typographical machine equipped with a rotary main shaft provided with a series of cams controlling the operation of various movable organs of the machine, driving mechanism therefor comprising a hollow drive shaft, a driving pulley loosely mounted on said shaft, a clutch fixed to said shaft and movable into and out of driving engagement with the driving pulley, a spring actuated axially movable rod contained within the hollow drive shaft and connected to the clutch, an axially movable sleeve surrounding the hollow drive shaft and pinned to said rod, said sleeve being shiftable in opposite directions to engage and disengage the clutch in starting and stopping the operation of the driving mechanism under normal operating conditions for a given machine cycle, a second spring actuated axially movable rod contained within the hollow drive shaft and arranged in end-abutting relation to the first rod, said second rod being connected by an inclined key and slot connection with the drive shaft so as to partake of a limited rotation and endwise movement with reference thereto, and a driving gear fixed to the second rod and meshing with a driven gear secured to the main cam shaft, whereby an overload of the driving mechanism, as caused by abnormal resistance to rotation of the main cam shaft during the machine cycle, will bring about the disengagement of the clutch from the driving pulley.

22. As a new article of manufacture, the hollow drive shaft referred to in claim 21, characterized in that the shaft is hollow throughout its length to accommodate both of the axially movable rods.

23. As a new article of manufacture, the second axially movable rod referred to in claim 21 with its key for connection with the hollow drive shaft and the driving gear which it carries.

24. As a new article of manufacture, the hollow drive shaft referred to in claim 21 with both of the spring actuated axially movable rods assembled and arranged to operate in the manner set forth.

JOHN H. HILPMAN.

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