US2626452A - Stock feed mechanism - Google Patents

Description

11953 G. o. GRIDLEY STOCK FEED MECHANISM 3 Sheets-Sheet l l irPlllll.

Mali nw Filed Dec. 20, 1947 3maemor' GEORGE O. GRIDLEY attorney @E Q Q K J 1953 G. o. GRIDLEY STOCK FEED MECHANISM 3 Sheets-Sheet 2 Filed Dec. 20, 1947 am ac Zinventor GEORGE O, GRIDLEY attorney Patented Jan. 27, 1953 rarest sis New Britain Machine Company, New Britain,

Conn, a corporation of Gonnectieut Application December 2%, 1947, Serial No. 793,016

'2 Claims.

My invention relates to stock-feeding mechanisms for machines such as automatic lathes.

It is an object of the invention to provide an improved mechanism of the character indicated.

It is another object to provide an improved stock-feeding mechanism that may of itself accurately govern successive feeding advances of the stock without requiring that the machine to be fed be equipped with a stock stop.

It is also an object to provide improved supporting means in a stock-feeding mechanism of the character indicated, whereby the rear end of the stock may be more accurately positioned and held in alignment during the feeding process.

It is a more specific object to provide an improved extensibl stock-feeding mechanism, extensible beyond the back end of the machine to be fed and within the collet mechanism of the machine, whereby the stock may be fully consumed, insofar as it is usable.

It is a further object to provide an improved hydraulically actuated stock-feeding mechanism.

It is still another object to provide an improved electrically operated stock-feeding mechanism.

It is in general an object-to provide a relatively simple stock-feeding mechanism that may be readily adapted to a machine of the character indicated, that is not likely to get out of order, and that may be easy to maintain.

Other objects and various the invention will be pointed out or will occur to those skilled in the art from a reading of the following specification in conjunction with the accompanying drawings. In said drawings, which show, for illustrative purposes only, preferred forms of the invention;

Fig. 1 is a simplified side view in elevation of a stock-feeding mechanism according to the invention, as applied to feeding an automatic lathe;

Fig. 2 is a right-end view of-the Fig. 1, partly sectionalized in the plane 2-2 of Fig. 1;

Fig. 3 is a schematic diagram of control circuits for the system of Fig. 1;

Fig. 4 is an enlarged partly sectionalized view of feeding elements of the mechanism of Fig. 1;

Fig. 5 is a fragmentary detail of part of the Fig. 4 assembly;

Fig. 6 is a sectional view taken in the plane '5-6 of Fig. 4;

Fig. 7 is a side view in elevation illustrating an alternative construction according to the invention; and

Fig. 8 is a schematic view of con rol ii eans for the arrangement of Fig. '7,

further features of assembly of Briefly stated, my invention contemplates the utilization of chain or belt means to drive the pusher of a stock-feeding mechanism in such a way that the stock feed-out distance (in the machine to which the feed mechanism is adapted) may be the same for successive operations, reardless of the usable length of stock remaining unconsumed. The feed-out operation may be positive, so as to avoid the need of a stock stop on the machine which is being fed. The pusher means may include a longitudinally extending portion longitudinally mova. 1y supported in a guided carriage, which is preferably detachably latched in a forward position (relative to the pusher means), for best support of the butt end of the stock; when unlatched, the pusher means may be extended through the machine, even to the collet jaws thereof.

In both forms to be described, the stock-feed mechanism includes pusher means guided by longitudinally extending ways. The pusher means is attached to an endless belt in the form of a sprocket chain which is spread between sprocket wheels at both ends of the feed mechanism. Drive may be applied to the pusher means through one of the sprocket wheels, by way of a worm-and-wcrm-wheel reduction system. In one form, a reciprocable hydraulic motor and suitable clutch means drive the worm, and in the other form, an electric motor and suitable clutch means drive the worm. In both cases, means are disclosed for appropriately synchronizing stockfeeding operations with the functioning of the collet or chuck of the machine which is being fed.

Referring to Figs. 1 to 6 of the drawings, my invention is shown in application to a stockfeeding mechanism for supplying bar or tubular stock IE5 to an automatic lathe II. The lathe H includes a spindle l2 for revolubly supporting the stock is, and chuck means in the form of a socalled draw-back collet I3 serve to clamp the stock it for turning operations. In the automatic lathe l I it so happens that the rear end M of the collet-and-spindle assembly l2l3 is considerably forward of therear end I5 of the lathe H.

The stock-feeding mechanism may include pusher means in the form of a pusher carriage It to be guided by guides or rails I! on the frame l8 of the stock-feeding mechanism. Rollers 5l52--53 may assure smooth travel of carriage it along rails I! as well as alignment (vertical and lateral) and resistance against jumping. The pusher carriage [6 may be secured, as at [9, to endless-belt means in the form of a sprocket chain 29. The chain is trained over supporting sprocket wheels 2l-22 at opposite ends of the frame I8, and drive means may be applied to the rear sprocket wheel 22. If desired, chaintightener means 23 may be employed to assure positive positioning of the pusher means It; at all times.

In the form shown, the drive means for the drive-sprocket wheel 22 is hydraulically operated from a cylinder 24, the piston of which is connected to reciprocate a rack 25. Limiting advances for the rack 25 may be adjustably selected by means of a screw abutment 26 having lock-nut means 27 to secure a given abutment position. The rack 25 may drive a pinion 28 on a generally vertical shaft so as to impart rotation to a worm 29 for a worm wheel 30, in driving relation with the sprocket Wheel 22. So that the motion of the drive chain 20 may always be in the same direction, I provide one-way engaging or ratchet clutch means 3| between the pinion 28 and the worm 29. It will be clear that, upon a feeding stroke of the rack 25 (left to right in the sense of Fig. 1), as limited by adjustment of the abutment means 26, there may be a given feeding advance of the pusher means I 5. While the rack 25 is being retracted and positioned for the next feeding stock, the ratchet clutch 3! does not engage and no motion is imparted to the drive chain 30. This simple reciprocating cycle may repeat itself until there is no further usable unconsumed stock, as will be pointed out below.

After the feed means It has been fully advanced and it is desired to retract the same for accommodation of a new piece of stock I ii, it may be desired to disengage the worm 29 from the Worm wheel 38, as by lifting the handle of a bellcrank 32 pivoted at 33. The bellcrank 32 will be understood then to displace the sleeve 34 backward, as permitted by a universal joint 35, and to provide the desired disengagement of the worm 29 from the worm wheel 30.

As indicated generally above, the described feeding of the pusher means may be coordinated with operation of the collet l3 in the lathe II. The collet I3 is shown in the schematic arrangement of Fig. 3 to be actuated by a spool 36 in which a cam-follower fork 31 rides. The cam follower 3'! may follow the track or groove of a drum cam 38, which may be on the main camshaft 39 of the lathe II. A shift of the fork 31 to the right pushes the collet [3 to disengage it from the stock [0, and a shift to the left draws the collet 13 back to a chucking position. The hydraulic cylinder 24 may be reversibly actuated by a reversing valve 40, which in turn is connected to reverse its functions upon a shift of collet-actuating means 31. In the position shown, the valve 40 connects a source 4] of pressurized fluid to the tail end of cylinder 24, so as to retract the rack 25 and to position the same for a feeding stroke. Upon disengagement of collet l3, as when the fork 31 is shifted to the right, the valve 40 will be reversed so as then to apply pressurized fluid to the head end 42 of cylinder 24. A working stroke, and, hence, a feed of pusher means I6, is then quickly accomplished, as limited by the adjustment of the abutment screw 26. During the working stroke, fluid in the tail end of cylinder 24 may be connected by valve 40 for exhaust to the sump 43. When the collet l3 has been clamped on the newly fed-out stock, the valve will be shifted back to the position shown so that the rack 25 may be repositioned for a feed stroke. It will be understood that,

during the repositioning of the rack 25, the overrunning clutch may effectively disengage the rack-and-pinion means from the pusher means It.

In order that the feed-out operation may be accomplished without requiring a stock stop in the working area of the lathe II, I employ a chuck 44 carried by the pusher assembly for secure attachment to the tail end of the stock I0, so that the stock will not continue to feed after the feed thrust stops. The chuck 44 may be and preferably is accurately positioned in alignment with the axis of spindle I2, and for this purpose I provide a supporting carriage 45, which will be referred to as the forward carriage. The forward carriage is preferably longitudinally movable with respect to the pusher means, and it may be guided by the rails IT; for a purpose which will be clear, the forward carriage is detachably latched against longitudinal movement with respect to the pusher means. In the form shown, the pusher means includes a longitudinally extending cylindrical portion or bar 48 to support the chuck 44, and the bar 45 may derive support from both carriages l645, as by being journalled therein. Antifriction bearing means :27 are shown to provide revoluble support of the pusher bar 46 in the rear carriage I G, and the bearings 4'5 are preferably of a thrust-sustaining type, so that they may be preloaded to assure an axially locked relation between the bar 43 and the pusher carriage 16. In the form shown, adjustable take-up means 48 and a shoulder 49 provide the means for preloading the bearings 41.

As indicated above, the pusher bar 46 is preferably slidable with respect to the forward carriage Since the bar 46 rotates with the stock 10, I prefer to employ antifriction bearing means 56 which may be of the so-called needle type to assure the desired antifriction revoluble and longitudinally slidable support. As also indicated, the forward carriage is preferably detachably latched against longitudinal movement with respect to the pusher means. In the form shown, the detachable latch means utilizes a spacer bar 55, which may be carried, as by a pivot pin 56, on one of the carriages (45) and latched to the other carriage ([6) as by engagement of a notch 51 on bar 55 with a ledge 58 on the other carriage (l6). Resilient means 59 may act upon a shoe 68, to retain the spacer bar 55 in the latched position shown.

To detach the latch means, the spacer bar 55 and the frame i8 may include cooperating elements to cause unlatching of the bar 5-5, as by an unseatlng of the notch 5'! from ledge 58 when the forward carriage 45 arrives at the front end of Ways H. In the form shown, this unlatching mechanism utilizes a transversely extending bolt or rod 61 between the rails I! and a projection or lugs 62 on the spacer bar 55. The projection 92 preferably engages the rod 6| so as to detach the late means 55 just before the end of possible travel of the forward carriage 45 on the rails :3. In the form shown, this unlatching occurs just prior to a positive arresting of the forward car-- liege 45 by means of an abutment 63 spanning the rails ll. It will be understood that, after unlatching, he forward. carriage 65 may continue to provide aligning support for the stock l9 while the usher bar 45 is extended; if the chuck 4t is designed to fit within the spindle 12, then the stock 16 may be fully consumed, insofar as it is usable, by feeding the butt of stock I within the spindle up to the jaws of collet [3.

In Figs. '7 and 8, I show a modified form of the invention in which an electric motor 78 is employed to drive a stock-feeding mechanism for an automatic lathe H, which may be of the same type as described above. In the form shown, clutch means ll-E2 couple the motor Hi to a worm It for a worm wheel 14, to drive the drive sprocket wheel 22. From this point, that is, from the drive-sprocket wheel 22, the stock-feeding system may be generally similar to that which has been already described. Thus, pusher means employing a forward detachably latched sliding carriage @5 may carry a chuck 44 to grip the stock Iii; the pusher means may also be driven by the sprocket chain 2K3, as through the rear or drive carriage it.

In the form shown, the clutch II is a dog clutch which may be manually operated (by means not shown) whenever it may be desirable to uncouple the motor Hi from the rest of the drive system, as in manually controlling the stoppage of a feeding operation. For automatic control of the feed-out of stock [0, the clutch '12 may be electrically operated, as by a solenoid 7'5, which is shown normally urged by the spring 76 to cause engagement of the clutch 72. When the solenoid T5 is energized, the spring it is compressed and the clutch 12 disengages.

In order to coordinate the electrically driven stock-feeding mechanism with normal automatic operation of the collet It in the lathe I I, an additional cam disc 11 may be mounted upon the main camshaft 39 of the lathe I l, and in the form shown cam elements iii-i9 are adjustably positionable about the cam disc TI to provide a desired operating sequence of cam-follower operated switches kid-Bl, respectively. The switch 8! is normally open and shown to be in the con- 1 trol circuit for the motor it, while the switch 8% is normally closed and connected to operate the solenoid '55. The cam 19 is preferably so positioned with respect to the collet-disengaging rise of cam 38 that the motor '50 will be energized (to produce a feed of the pusher means) as soon as the collet jaws are released enough to permit such feed; the high or actuating surface of cam I9 preferably drops to shut off the motor 19 at about the time when the collet jaws are set to clamp the newly fed-out stock 19. The cam I3 may be of greater arcuate extent than the cam 79; and its trailing edge, that is the edge controlling energizing of solenoid l5 and hence declutching, is'prefera'bly set in accordance with the desired feed-out distance for the stock It. Since the cam l8 may be of longer efiective duration thanthe cam 19, it will be clear that regardless of the feed-out distance to be controlled by cam T8, the clutch 12 may always be positively engaged when the motor is turned on. There may thus be assurance that whatever the selected feed-out distance, such feed-out distance may be uniformly duplicated for each feedout operation.

It will be seen that I have described relatively simple stock-feeding mechanisms for positively assuring equal successive feed-out distances while eliminating the need for a stock stop in the working area of the machine to be red. Either of the forms described is comprised of essentially simple elements, and the arrangements are such that maintenance is not difilcult. In either form, it is a relatively simple matter to select the feedout distance which is required; and, regardless of the size of the feed-out distance, it may be reliably duplicated no matterhow much usable stock remains unconsumed. Although, for clarity, no means have'been shown in either of the described arrangements for shutting of the feed when there is no usable stock left, it will be understood that simple disabling or shut-off means may be employed to cooperate between the pusher means and some fixed part or position.

Although in each of the described forms of the invention a sprocket chain has been employed as the drive medium for thestock pusher, other equivalent belt-like elements, such'as metal tape, belts or the like may be used. For this reason, the term belt has been adopted as a generically descriptive term for sprocket and equivalent means.

While I have described my invention in detail for the preferred-form shown, it will be understood that modifications may be made within the scope of the invention as defined in the appended claims.

I claim: j

1. In a stock-feeding mechanism of the character indicated, a frame including longitudinally extending guide means, two carriages to be guided by said guide means, a pusher bar supported in each of said carriages, the forward of said carriages being longitudinally movable with respect to said bar and the rearward of said carriages being locked against axial displacement with respect to said bar, feed means for feeding said rear carriage, detachable spacer means positively and directly abutting axially fixed parts of said carriages for spacing said carriages, said spacer means placing said carriages in direct thrusting and driving abutment relation in one position thereof, and unlatching means on said frame and positioned to intercept and to displace said spacer means from said one position and to a position disengaging said carriages, whereby after said disengagement continued feeding of said rear carriage may extend said bar through said forward carriage and. into the rear of a machine into which stock is being fed.

2. In a stock-feeding mechanism of the character indicated, a frame including fixed elongated guide means, forward and rear carriages independently slidably guided by said guide means, feed means for said rear carriage, pusher means including a substantial elongated cylindrical guide portion and with means at one end to engage a piece of stock to be fed, bearing means axially fixedly carried by each of said carriages and rotatably supporting said pusher means with said cylindrical guide portion axially slidably supported in the bearin means in said forward carriage, releasable spacer means positively and directly spacing axially fixed parts of said carriages, and means coacting between said frame and a part of said spacer means for releasing said spacer means upon movement of said carriages to a given point along said fixed elongated guide means.

3. A stock-feeding mechanism according to claim 2, in which said feed means includes endless-belt means, and reciprocable hydraulic means including a rack and pinion mechanism positively connected to said belt means for driving said belt means in positive increments in ac cordance with the stroke of said hydraulic means.

4. A stock-feeding mechanism according to claim 3, in which said feed means includes adjustable stop means for said hydraulic means,

whereby the positive feed increments may be adjustably selected.

5. A stock-feeding mechanism according to claim 2, in which said feed means includes endless-belt means, and motor driven worm-andwheel mechanism positively connected to said belt means for positively driving said belt means.

6. In a stock-feeding mechanism of the character indicated, a frame including fixed elongated guide means, a carriage slidably guided by said guide means, pusher means including a substantial elongated pusher bar directly slidably received in and supported by said carriage and including stock-engaging means at one end to engage a piece of stock to be fed and feed-thrust means at the other end, whereby the fed-thrust end and the stock-engaging end of said pusher means extend on opposite sides of said carriage, releasable spacer means positively and directly abutting axially fixed parts of said feed-thrust means and of said carriage, said spacer means positively holding said feed-thrust means at a maximum extended position rearwardly of said carriage, and means coacting between said frame and a part of said spacer means for releasing said spacer means upon movement of said carriage to a given point along said fixed elongated guide means.

7. In combination, a lathe-type machine including an internally fed collet and collet-actuating means; and a stock-feeding mechanism comprising a frame including fixed elongated guide means, forward and rear carriages independently slidably guided by said guide means, feed means for said rear carriage, pusher means includin a substantial elongated cylindrical guide portion and with means at one end to engage a piece of stock to be fed, bearing means axially fixedly carried by each of said carriages and rotatably supporting said pusher means with said cylindrical guide portion axially slidably supported in the bearing means in said forward carriage, releasable spacer means positively and directly spacing axially fixed parts of said carriages, and means coacting between said frame and a part of said spacer means for releasing said spacer means upon movement of said carriages to a given point along said fixed elongated guide means; said feed means including endless-belt means, reciprocable double-acting hydraulic means including a rack-and-pinion mechanism positively connected t said belt means for driving said belt means in positive increments in accordance with the stroke of said hydraulic means, and reversing-valve means for said cylinder and connected for actuation in timed relation with said collet-actuating means.

GEORGE O. GRIDLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Nmnber Name Date 324,409 Nutting Aug. 18, 1885 497,631 Conradson May 16, 1893 1,101,716 Seaman June 30, 1914 1,663,599 Hornberger Mar. 27, 1928 1,855,515 Dingell Apr. 26, 1932 2,249,561 Jelinek et a1. July 15, 1941 2,369,466 Kylin et a1. Feb. 13, 1945

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