US2626450A - Bar feed means - Google Patents

Description

G. C. GRIDLEY BAR FEED MEANS Jan. 27, 1953 3 Sheets-Sheet l a a a INVENTOR 650/665 0. 66/045) ATTORNEYS Filed Dec. 20, 1947' G. o. GRIDLEY BAR FEED MEANS Jan, 27, 1953 5 Sheets-Sheet 2 Filed Dec. 20, 1947 INVENTOR 6:0?66 O. file/045x BY v ATTORES Jan. 27, 1953 v G. o. GRIDLEY BAR FEED MEANS Filed Dec. 20, 1947 3 Sheets-Sheet 3 INVENTOR 650/965 0. GR/DLEY ATTORNEYS Patented Jan. 27, 1953 BAR FEED MEANS- George 0. Gridley, Berlin, Oonn., assignor to The New Britain Machine Company, New Britain, Conn., a corporation of Connecticut Application December 20, 1947, Serial No. 793,013

7 Claims.

My invention relates to automatic machines,

and in particular to automatic stock-feeding mechanisms for bar machines.

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 employing hydraulic J actuating means.

actuated mechanism of the character indicated, wherein a given stock-feed stroke may be adjustably selected so as to obviate the need for the stock stop.

Other objects and various further features of 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:

Fig. 1 is a simplified side view of an automatic lathe to which a stock-feed mechanism according to the invention has been applied;

Fig. 2 is an enlarged sectional view taken substantially in the plane 22 of Fig. 1;

Fig. 3 is a sectional view taken substantially in the plane 33 of Fig. 2;

Fig. 4 is a schematic arrangement of hydraulic actuating circuits for the mechanism of Fig. 1;

Fig. 5 is a view similar to Fig. 1, but illustrating a modified construction;

Fig. 6 is a sectional view taken substantially in the plane B6 of Fig. 5;

Fig. 7 is another view similar to Fig. 1 to illustrate a still further modification of the invention; Fig. 8 is an enlarged detailed view of a portion of the mechanism of Fig. 7; and

Fig. 9 is a sectional view taken in the plane 9-9 of Fig. 8.

Briefly stated. my invention contemplates an improved stock-feeding mechanism that may be employed periodically to feed out tubular or bar stock, say, through the collet or chuck of an automatic lathe. Fluid-pressure actuating means propel the stock substantially for the feed-out distance before recycling for the next feed-out operation. In the forms to be described, the

pressure actuating means is hydraulic and drives a drum or winch over which a cable is payed for attachment to the feed carriage. Various mechanisms are shown for engaging the hydraulic actuating means to the drum, and in one form 2 the feed stroke may be adjustably selected without modifying the stroke of the hydraulic actuating means.

Referring to Figs. 1 through 4, my invention is shown in application to a stock-feeding mechanism for an automatic lathe I0 having a spindle revolubly to support tubular or bar stock I2,

as in an internally fed collet or chuck I3. The stock-feed mechanism may include a feed carriage I4 slidable in longitudinally extending ways in a frame I5 at the rear end of the automatic lathe III. The carriage I4 may incorporate a long tudinally adiustable abutment member I6, having a centering nose I! for the case of the tubular stock I2 shown. The centering nose I! is preferably freely rotatable with respect to the abutment member I6 so as to provide efiective support for the rearwardly projecting end of stock I2.

In accordance with the invention, hydraulic actuating means are employed periodically to advance the stock I2 to a new feed-out position when lathe operations have been completed on the previously fed-out stock. A limiting feed-out position may be determined by a stock stop I8. In the form shown, hydraulic actuation for the stock-feed mechanism is derived from the motion of a piston I9 traveling in a cylinder 20 fixed relatively to the frame I5. The motion of piston I9 may be emnloved to drive a drum 2| carrying a cable 22 attached at one end, as at 23, to the feed carriage I4. The piston rod 24 for the hydraulic actuating means may carry a rack 25 which may slide in ways 26, so as to be positioned for drivin engagement with a gear 21 for driving the drum 2|.

One-way-engaging ratchet means 28 may be provided between t e gear 21 and the drum 2| to permit the drum 2| to overrun the gear 21 (if possible) or to permit recycl ng of the piston I9 for again driving the gear 21. In the form sho n, the gear 2'! is keyed at 29 to the hub of driving member 30 of the ratchet mechanism 28. The driven part of the ratchet mechanism 28 may be formedintegrally with the drum 2|, as by prorviding the drum 2| with a bore 3|. For set-up purposes, the drum 2| may be keyed, as at 32, to a supporting shaft 33 having at One end a projection with flats 34 to be engaged as by a crank. The ratchet mechanism 28 may include one or more slidable pawl members 35, which are shown as rollers. The rollers 35 may be s ring urged for wedgi'ng contact between the bore 3| and flats 36; the flats 36 may be milled in the driving member 30 of the ratchet mechanism 28.

In accordance with a feature of the invention, I provide means whereby in addition to the positive driving action of the hydraulic actuating means upon the drum 2| there may be a substantially constant further feed force applied through cable 22 to the feed carriage 23. In the form shown, this further force is derived from a weight 31 attached to' the other end of the cable 22 and 'suspended as over an elevated pulley 38. The pulley 38 may be located above the machine, or a hole (not shown) in the shop floor may provide clearance for the full travel of the weight 31. Itwill be clear that if the cable 22 is wound a number of times over the drum 2| (see Fig.2), the weight 31 may perform the dual function of applying a constant feed force to the carriage I4 and of assuring an adequate cable-grip uponthe drum 2|, so that hydraulic actuation of drum 2| may be effective to feed even the heaviest stock I2.

In the preferred arrangement shown, the working stroke of'the piston I9 is at-least sufficiently long to permit a full feed-outof stock I2 to a stock stop IS, without requiring furtherhydraulic'feed strokes. If the stock' stop I8 should'be placed relatively close to the-chuck I3, as when short pieces of work are to be'formed on'the lathe, then it'will be cleartthat the'nature' of cable engagement with the'drum will permit cable slip action once'the stock I2'has'hit the stookstop I8. This slip action'will be characterized by a full stroke of piston I9 and by a correspondingly complete arcuate advance of the drum '2 I; atthe same time, the amount of cable advance: may only beJrela- 'tively smalLasdetermined bylthepositionof stock "stop I 8.

Referring toFig. 4,1 illustrate schematically a method of automatically recycling 'thehydraulic actuating means I9. In Fig. 4,'the work I2 will be recognized as held by the drawback chuck or collet 'I3, which in turn is seated in'and revolubly'supportedby the spindle I I. Actuation of the drawback collet I3 may be effected through a collet tube I3, supportin at its rear end an actuating spool -39.having an annular-groove 40 to be engaged as by a fork 4|. In the form shown, the

fork 4| issupported on a sliding bar 42 and carries at one end a cam follower roll 43 toengage the cam slot in a drum cam 44, which may be ontthe cam shaft of the lathe III.

The sliding bar 42 on which the fork 4| is lmounted may also'be employed to position the crank '45 of a control-valve 46 for reversibly actuating the piston I9. In a first-position of the valve-46, a first passage'41 connects a source 48 f hydraulic pressure through line :49to the head end of the cylinder 20 so as to actuatepiston I9 from left to'right. i'lhis will berecognized as a retracting stroke whereinthe ratchet mechanism 28-does not engage rand wherein, therefore, no motion is impartedtddrum 2| or to the carriage I 4. Durin this retraction-stroke of the piston I9 exhaust fluidis expelled from the tail end of the cylinder 2|! through'a pipe 52to a secondpassage 50in the valve"46,f0r conduct to a sump .The

x.descr'ibed retractionstrokewill be appreciated as :occurring at the beginning of the1relatit1elylong dwell on 'cam "44; piston I9 will remain soretracted for the duration of "the dwell, "as will be clear.

In the second position of valve 46, as when the follower 43 is intherelatively short rise of cam 44 (Le. when the collet is open) the passage 41 directspressurized'fiuid t0 the tail end of cylinder 20 to drive-the piston I9 from right to left. In this second stroke the ratchet mechanism 28-will .drive gear be understood to engage, so that stock-feeding motion will be imparted by the hydraulic actuating mechanism to the drum 4|, and hence to the carriage I4. During this second or feed stroke, exhaust fluid from the head end of cylinder 20 will be directed through the exhaust passage 50 in valve 46, for discharge into the ump 5|.

'It will be appreciated that since the valve 46 is directly actuated by the mechanismwhich also actuates the collet I3, the necessary stock feed :forces may be applied to advance stock I2 only when the collet I3 is open. When the cam follower 43 again rides in the dwell on cam 44, the

-valve'.46 is positioned to reset the hydraulic actuating cylinder 20 and its piston I9 for the next feed stroke. It will be recalled that throughout the described cycle of events the weight 31 will have been effective at all times to assure some load -ina feeding direction on the carriage I4 and that such load may at least have been effective to provide adequate support for the projecting and 'otherwiseunsupported back end of stockI 2.

In Figs. 5 and 6, I show a modified form of the invention in which hydraulic actuating means drive feed carriage I4 through another typeof ratchet engagement. Much of the structure of Fig. 5 will'be recognized from Fig, 1, that is,-the carriage I4 may be slidable along a frame I5 and support stock I2 for feeding through theback "end of an internally fed chuck I3 in an automatic :lathe III. A stock stop I8 may serve to determine limiting advances of the fed-out stock I 2. .The hydraulic actuating means againmay-include a gpiston.lilslidable in a cylinder 20 and driving a ratchet wheel 6| may be formed with the drum 56 or locked thereto, as by key means 62.

It will be appreciated that in Fig. 5 the working stroke of the hydraulic actuating means I9 may be'in the same direction as that shown in Fig. 1. In other words, feed motion may be imparted to :the drum 56'and hence to the feed carriage I4 upon-a right-to-left displacement of piston I 9. In this displacement the pawl 60 may be carried by gear 54 in a single positive engagement'with the ratchet wheel 6| so as further to wind cable 5! on the drum 56. Upon retraction '(left to right) -'of thepiston I9, the pawl 60 will be allowed to escape a number of teeth of the ratchet wheel-6| and this number will depend upon the extent to which the stock stop l8 permitted a feed ofnew stock |2. During retraction of piston l9 and until the hydraulic actuating mechanism'is again energized to feed the stock, holding forces may be continuously applied to the .stock .I.2 by means of a. holding ratchet'63,-backring .up the ratchet'means 60. may be:effective to lock drum 56 to the frame The ratchet 63 except when the chuck forces are being applied.

The arrangement of Figs. 5 and 6 will be appreciated as providing for a relatively positive application of feed forces to the feed carriage I4. When a feed stroke is limited by abutment of the stop |2 with thestock stop IS, the motion of piston I9 will bemomentarily arrested, and'the I3 is open and feeding fastening pawl 63 will serve to hold the cable taut in this fed-out position. Reclamping of the collet l3 will be accompanied by a return of the piston l9 to the position shown, while the pawl 63 may retain the strong feed-out forces in their application to the rear end of the stock l2.

7 In Figs. '7, 8, and 9, -I show still another modification of the invention, wherein the stroke of the hydraulic actuating mechanism may be adjustably selected so as to obviate the need for the stock stop l8 of the above-described mechanisms. The arrangement of Figs. '7, 8, and 9 will be recognized as being applicable to an automatic lathe having an internally fed collet or chuck I3 for holding stock (2 in position to be turned in a spindle l I. The rear end of the stock [2 may be fed and supported by the centering piece I! of an adjustable bar l6 carried by a feed carriage l4, and the feed carriage l4 may be slidable in a frame [5. Hydraulic actuating forces may again be derived from the working stroke of a piston [9 to drive a drum 65 supporting a cable 66, which in turn may be attached at one end to the feed carriage 14, as at B1.

The drum 65 may receive its feed motion from a gear 68 having a portion to cooperate with ratchet means 69. The ratchet means 69 may include a sliding pawl similar to those described in Fig. 3. In the form shown, the gear 68 is engaged by a sector gear 10 keyed to a crank H, and the crank H is thrown by a link 12 directly connected to the piston rod 2|, as at a crosshead 13 traveling in guides 14.

In accordance with the invention, the link 12 may be attached at adjustably selected points on the crank II, as determined by the position of a block I in a slot 16. It will be appreciated that with the mechanism described a right-toleft stroke of the piston l9 may cause positive engagement of the ratchet 69 so as to drive drum 65 clockwise (in a winding direction), to feed the carriage l4 and hence the stock l2. If the adjustable block 15 has been properly set for a desired feed-out advance of the stock l2, then there may be no need for a stock stop, and a full stroke of the piston l9 may accomplish a full feed-out advance of stock I2. As in the case of Fig. 4, a clamping of the collet 13 may be accompanied by a recycling or left-to-right re turn of piston l9 into position for another feedout stroke. During this return stroke, another one-way engaging ratchet mechanism 1'! between the drum 65 and the frame 18 will be understood to hold the cable 66 and thus adequately to support the tail end of the stock l2.

It will be appreciated that I have described relatively simple stock-feed mechanisms which, compared with existing structures, may be small, compact, and efficient. In all cases, there need be no danger of overstressing the mechanism, even when fed-out stock is arrested by a stock stop. Furthermore, in all cases provision may be made for assuring a constant application of force in a feeding direction so as to support the rear end of stock even when the actuating mechanism is being recycled. In the preferred form wherein relatively incompressible fluids are employed, the action of my stock-feed mechanism will be understood to be smooth, positive, and accompanied by no bouncing of the stock.

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

P Iclaimz 1. In a machine of the character indicated, a feed carriage, and hydraulic actuating means for propelling said carriage, said hydraulic actuating means including a cylinder, a piston, a piston rod, and a crank, rotatable means connected to said carriage and driven by said crank and means adjustable along the length of said crank for connecting said piston rod to said crank, whereby the extent of feed may be adjusted by selective placement of said adjustable means on said crank.

2. In a machine of the character indicated, a feedcarriage, longitudinally extending guide means for said carriage, feed means for said carriage, said feed means including a drum, cable means on said drum and connected to said carriage, hydraulic actuating means for driving said drum, ratchet means for one-way engagement between said hydraulic actuating means and said drum, and gear means connecting said hydraulic actuating means to said drum, said gear means including a pivoted member, a crank having an adjustable arm rotatably driving said pivoted member, and connecting means linking said hydraulic actuating means and the adjustable part of said arm.

3. In a machine of the character indicated, chucking means to receive internally fed stock, a feed carriage and elongated guide means therefor for feeding stock to said chucking means, chuck-actuating means for opening and for closing said chucking means, double-acting fluidpressure-operated actuating means for feeding said carriage, a one-way-engaging connection between said fluid-pressure actuating means and said carriage, reversible fluid-pressure control means for reversibly operating said fluid-pressure-operated actuating means, and means interconnecting said fluid-pressure control means and said chuck-actuating means for changing the setting of said control means in response to an operation of said chucking means, the interconnection established by said last-defined means being such as to determine a first flow of pressure fluid to said fluid-pressure-operated actuating means in a feeding direction for a chuckopen position of said chuck-actuating means, such inter-connection further being such as to determine a second flow of presusre fluid to said fluid-pressure-operated actuating means in a retracting direction for a chuck-closed position of said chuck-actuating means; whereby, in a single coordinated movement of said chuck-actuating means and of said fluid-pressure control means from one of said positions to the other, said chucking means may be opened and a length of stock fed; and whereby, in another single coordinated movement of said chuck-actuating means and of said fluid-pressure control means from the other of said control positions to the one, the stock may be chucked and said pressureoperated actuating means retracted.

4. A machine according to claim 3, and including feed means for said carriage and acting over and above said pressure-operated actuating means and constantly urging said carriage for propulsion in a feeding direction.

5. A machine according to claim 3, and including a drum, cable means around said drum and connected to said carriage at one end and weighted at the other end.

6. A machine according to claim 3, in which said pressure-operated actuating means for feeding said carriage includes a drum, cable means on said drum and connected to said carriage,

hydraulic actuating means for drivingsaid drum,

and further one-way-engaging means between said drum and said frame.

'7. A machine according to claim 3 in which said pressure-operated actuating means for feeding said carriage includes a drum, cable means on said drum and connected to said carriage,

gear means for driving said drum, and hydraulic means for driving said gear means, said one-wayengaging connection being between said hydraulic actuating means and said drum, and said gear means including a longitudinally slidable rack connecting said hydraulic actuating means to-said drum.

GEORGE O. GRIDLEY.

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

5 UNITED STATES PATENTS Number Name Date 1,663,599 Hornberger Mar. 27, 1928 2,369,466 Kylin et a1 Feb. 13, 1945 2,451,367 Twamley Oct. 12, 1948 FOREIGN PATENTS Number Country Date 571,614 Germany Mar. 8, 1933

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