US1573048A - Feed collet - Google Patents

Description

Feb. 16 1926.

c. J. FANCHER ET AL FEED COLLET Fi led Nov. i925 Patented Feb. 16, 1926.

UNITED STATES- CHARLES J. FANCHER AND ROBERT A, JonNsoN, or WTKDSOQ," V ERMON'i, mssren'ons TO THE NATIONAL ACME COMLP'ANY, 0F CLEVELAND, 01110, Ai ooltrolinrIoN or Application filed November tacos whereby a more durable and longer lived teed coll'et is obtained, in which there is less likelihood of: the marring or scratching ot the stock and in which less tension is required to secure a sutli'cient' i riction or grip on the stock, and byineans of which also the heat treatment of the collct is shit. plified, with the result that breakage of the collect largely avoided and in which'the tension of the collet may be adjusted by the operator at will so that there is no delay in prtnluction and no idle machines.

These improved feed collet's oi" pushers are adapted for use in various typeset machines such as metal working. machines; including automatic or hand operated screw machines, bar forming niachinesor the like, and are constructed especially for the purpose of feeding the stock or work. In the drawings accompanying and forming a part of this specification, Fig, I is a side view of this improved collet; Fig. 2 is a longitudinal sectional view of Fig.

Fig. 3 is a cross sectional view taken on 1ine'3-3' Fig. 2; and Fig. 4 isa perspective view of one of the sectional filler members. Similar characters of reference indicate correspondingparts in the several views.

Before explaining in detail the present improvement and mode of operation thereof, we desire" to have it understood that the invention is not limited to the details of construction and arrangement of parts which are illustrated in the accompanying drawings, since the invention is capable of other embodiments, and that the phraseology which we employ is for the purpose of description and not of limitationl The present improved feed collet' as shown PATENT FEED COLLET.

1, 1923. Serial Nb. 6%,057'. 1

herein in its preferred form' is for-tiled or rolled up" from a metal blank struck from or stamped out from piece of sheet metal such as a pressed sheet steel plate; I The blank usually comprises a body portio-nand a plurality of finger pieces'e' xtending or pr'o:

through. The contiguous'edges may be 0on nccted in any suitable inanner as by welding. The finger pieces 2 are then'bent, pressed or otlrerivise forced-inwardly a suitable distance or shaped in any suitable man: her and are shown spacedapart' by lengtln wise extending slots 3 wh-icl'r extend-back to the body 4 otthe collet. For the purpose of attaching the colletto the feed tube; the end of the collet isthreadeda's at 5 and a shoulder 6 is formed iira suitable manner. This shoulder may be formed by oifset'ting the blank; thus leaving more metal" under the threads to strengthen the body of the collet than would 7 otherwise-be the, case by turning down the body on the outside prior to threading. Secured 'to the inside"- of each finger is a filler member, section block or pa d 7, each of segmental form,theeurersurface of which conforms to' the inner; surface of a finger, while the innei" surface" of each pad is-shaped to conform to the shape of the work, and thesepads-or sect-ions are suitably secured, preferably by spot welding, to the fingers thus becoming a part thereof. From this it will be obvi'otis that by forming the collet of predetermined size various shapes and sizes of p'ads may be interchangeably secured to the col le't 'fiii'gers according t'oi the shape, size or form-1 0i the stool-i or work. In other words when a colle't of small size is desired small finer blocks may be inserted and secured to the" collet and when a c'olletof large sizes desired,

tiller members of larger size may be used.

for guiding and centralizing the end ofthe stock bar and thus preventing the-waste end of the stools from jamrliiiig the collet after the bar is fed completely through the collet, and the inner end of each filler'section is similarly tapered as at 9 to facilitate the feeding of each new stock bar into the collet.

In the present improved collet the filler members or sections 7 correspond substantially with the length of the fingers, that is to say, each filler member extends back from the forward end of the collet almost to the relieved portions 10 of the slots so that practically the whole length of the fingers corresponds to and fits the stock instead of as in our prior Patent No. 1,4:at9,505 of March 27, 1923, in which a very short filler block only at the front end of the collet fits the stock. By having these filler blocks of a length not substantially less than the length of the fingers some very important practical advantages are obtained. I ,7

In the first place it will be observed that the fingers fit the stock for nearly the full length of the resilient fingers, thus giving a longer gripping surface on the stock which reduces the scratching or marring of the stock, and requires very much less tension to insure a. proper or sufficient friction of the fingers on the stock, and consequently the operationof the pusher under less strain. In other words with a short filler block there is of course only a short gripping surface on the stock so that this requires considerable spring tension in the fingers to insure sulficient pressure of the fingers on the stock. By reason of the long filler blocks however and the consequently increased or lengthened gripping surface, the tension does not have to be so great and there is less liability ofbreakage of the fingers Where they join the-body. That is to say, by having the filler blocks almost the length of the fingers a greater gripping surface. is obtained on the stock sothat less resiliency ortension is required in the fingers. It has been discovered that the short filler blocks require great tension in the fingers, and therefore the long filler blocks make it possible to decrease the tension of the fingers. When the tension or spring of the fingers is high the fingers in operation arev liable to break ofi, but when the tension is low it has been discovered that the fingers may even be bent back without breaking them off. Thus by having the fingers fit the/stock throughout practically their full length, it is possible to so heat treat the fingers that a low tough temper is obtained with the result that the fingers will withstand almost any am ount of bending without danger of breaking while the gripping surface on the stock is materially increased, and suflicient flexibility is present tomaintain a good grip on the stock. i -By the use of this improved long filler block another advantage is obtained. Heretofore collets were heat treated by case hardening them,-packing them in the usual way and carbonizing them deep or nearly through, but by the use of this long filler block it is now merely necessary to heat them in a cyanide bath and then quench them, the result being that the collet is left with a low tough temper so there is little liability of breakage yet leaving sufficient flexibility in the fingers to afford a good grip, on the stock. In other words by reason of the long filler blocks which give an increased friction engaging surface on the work, it is possible to heat treat the collet in the manner'set forth, whereas heretofore they had to be so heated that the tension of the fingers was very great, and consequently while there is an increased amount of material in the filler blocks, the result is that the cost of manufacture isreduced, and a more durable, efficient and longer lived collet is produced. v

' The sections may be welded to the fingers in anydesired way and not necessarily by spot welding, for instance a single member or bushing may be inserted and welded to the collet fingers, the slots of which originally may be made somewhat wider than usual. Thereupon the welding material may be inserted or located through the slots of the fingers thus welding the cylindrical bushing to the fingers, especially along the edges of the slots. When the fingers are finished off on the outside to conform to the outside diameter of the fingers, slots of the desired width may be formed through the welded material by a suitable milling .cutter and through the bushing, these slots being preferably somewhat narrower than the original slots. By thi method of procedure it will be observed that the sections are welded their whole length to the edges of the fingers.

It is to be understood that by describing in detail herein any particular form, structure, or arrangement, it is not intended to limit the invention beyond the terms of the several claims or the requirements of the prior art.

Having thus explained the nature of our said invention and described a way of constructing and using the same, although Withthe interior diameter of the gripping por- Y tion according to the size of the filler means and comprising a plurality of sectional members, each of a length substantially as long as the resilient gripping portion and each secured to a slotted portion along sub stantially the entire length thereof.

3. A feed collet comprising a body portion, and resilient projecting gripping portions having a relatively low degree of tension and long stock gripping portions.

4. The method of making a feed collet which consists in forming a tubular member having a. body portion and slotted gripping portions, and then heat treating said collet to impart to the gripping portions a low degree of tension.

5. The method of making a feed collet which consists in forming a tubular member having a body portion and slotted gripping portions, providing the gripping portions with sectional filler members thereby to decrease the interior diameter of the collet, and then heat treating said collet to impart to the gripping portions a low degree of tension.

6. The method of making a feed collet which consists in forming a tubular member having a body portion and slotted gripping portions, providing the gripping portions with sectional filler members thereby to decrease the interior diameter of the col let, each of a length not substantially less than the length of its gripping portion, and then heat treating said collet to impart to the gripping portions a low degree of tension. t

7. The method of making a feed collet V a Q I v Winch consists in formlng a tubular member comprising a body portion and a slotted portion, then inserting a filler member therein, then Welding the filler member to the slotted-portion along the slots thereof, and then forming resilient gripping portions by cutting through the Weld and the filler member.

8. The method of making a feed collet which consists in forming a tubular member having a body portion and a slotted portion, then. inserting a filler member thereby to decrease the interior diameter of the collet, said filler ll'lGlTlbEDllttVlIlg a length substantially not less than the length of the slotted portion, then Welding the filler member to the slotted portion along the slots thereof, and then cutting through the Weld and the filler member to form resilient gripping portions, and then heat treating the collet.

9. The method of making a feed collet which consists in forming a tubular memher having a body portion and a slotted por tion, theninserting a filler member thereby to decrease the interior diameter of the collet, said filler member having a length substantially-not less than the length of the slotted portion, then Welding the lille-r member to the slotted portion along the slots thereof, and then cutting through the Weld and the filler member to form resilient gripping members, and then so heat treating the collet as to impart to the gripping portions a low degree of tension.

Signed at Windsor, Vermont, this 25th day of October, 1923.

CHARLES J. FANOHER. ROBERT A. JOHNSON.

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