US2047181A - Hydraulic feed for machine tools - Google Patents

Description

July 14, 1936. w. FERRIS HYDRAULIC FEED FOR MACHINE TOOLS Filed Nov. 18,. 1929 4 Sheets-Sheet 1 Y gva/vanto@ WA LTER F'EERIS.

ujy 13.4, 1936. w. FERRIS HYDRAULIC 'FEED FOR MACHINE TooLs Filed Nov. 18,v 1929 4 Sheets-Sheet 2 wuz'noz WALTER FEFQWS.

w. FERRls 21,047,181

HYDRAULIC FEED FOR MACHINE TQOLS Filed'No. 18,. 1929 4 sheets-sheet s July 14,1936.

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Patented 'July 14, 1936v PATENT CFFICE HYDRAULIC FEED FOR MACHINE TOOLS Walter Ferris, Milwaukee, Wis., assignor to The Oilgear Company, Milwaukee, Wis., a corporation oi Wisconsin Application November 18, 1929, Serial No. 407,920'

6 Claims. (Cl. 29-42) This invention relates to hydraulic feeds primarily for lathes although the novel features thereof may also be applied to advantage to other types of machine tools involvinga member to be translated.

One object of the present invention is the provision in a hydraulic feed mechanism of new and improved means for automatically regulating and controlling the rate and direction of movement of the driven member. In my copending application Serial No. 349,922 filed March 22, 1929, I disclosed a hydraulic feed mechanism for lathes involving a variable deliveryr pump under the control of a cam on the driven member which functions automatically to effect rapid traverse movement in either direction and a feed movement at either of two speeds during travel in one direction. The present invention provides a cam control responsive to movement of the driven member for automatically effecting a feed movement at any of an infinite number of speeds as predetermined by the contour of the cam, in addition to the rapid traverse movements heretofore provided.

Another object of the present invention is the provision in a machine tool having a plurality of separate members to be driven of a new and improved automatic control for effecting the movement of said members at predetermined speeds and in different directions in predetermined "sequence.

Other more specific objects and advantages will appear from the following description of an illustrative .embodiment of the p resent invention.

In the accompanying drawings:-

Figure 1 is a top plan view of an automatic lathe equipped with; a hydraulic feed mechanism embodying the present invention.

Fig. 2 is a view in front elevation.

Fig. 3 is a view in end elevation of the right end of the machine.

Fig. 4 is a detailview of a portion of the control mechanism shown in Fig. l, with the control lever in a different position.

Fig; 5 is a diagrammatic view oi the hydraulic system.

Fig. 6 is a sectional view .ci a pilot valve shown in Fig. 5 illustrating a second position thereof.

Fig. l is a sectional view 'of an auxiliary control valve shown inlig.4 5L, illustrating a second position thereof.

Fig. 8 is a top plan view of the main carriage of the lathe.

The lathe shown comprlsesthe usual bed I ll supporting a conventional head'stock I l provided with a rotary jaw chuck l2 for receiving the work W. The bed is also provided with the usual longitu'dinal ways i9 upon which the main carriage M is mounted in a well known manner for lengthwise travel toward and from the work. In this instance the main carriage it is hydraulically driven by a piston l5 connected thereto by a rod it and fitted for reciprocation within a motor cylinder il fixed to the bed i9. The main carriage ld supports a multi-position tool-carrying turret I8 of conventional design. The turret shown may assume any of six positions and is automatically rotated from one position to the next during completion of each return stroke of the carriage. This automatic step-by-step rotation of the turret it is edected in this instance by a rack bar 9 mounted for lengthwise reciprocation in appropriate brackets 9 ilxed to the bottom of the carriage it, V(see Fig. 8). The rack bar 9 meshes with a segmental gear 'i on the driving element 9 of a ratchet clutch of the type described in the copending application hereinabove identified. A compression spring 5 urges the rack bar 9 toward the right, the bar 9 being shifted toward the left against the pressure of this spring by a stop element d, fixed to the bed |19 of the machine, during each return stroke of the carriage.l

The main carriage ld also carries two multiposition control drums |19 and 29 which are both intermittently rotated from position to position by the turret i9 through a cross-shaft 2l =(Fig. 3). Shaft 2l carries a gear 22, which meshes with a gear 23 driven by the turret, and two gears 2d and 29, which mesh with gears 26 and il! conf nected to the respective control drums. A third auxiliary control drum 29 is also carried by the main carriage and is permanently connected to the control drum 20 for rotation therewith.

The lathe shown is also equipped with a back carriage 99 mounted for travel lengthwise of one of the ways i9. The back carriage is hydraulically actuated by a piston 99 connected thereto through a rod 9i and tted for reciprocation in a cylinder 92 on the lathe bed. Astop 33 on the lathe bed limits the movement of carriage 29 toward the right (Fig. 1) movement inthe other direction being limited by the abutting engagement of the piston 99 against the leftend head of the cylinder 32.

movement with the carriage' lengthwise of 'the versely of the lathe. v ,A lug 36 on the holder 34 A toolholder 3d of conventional def signv is mounted on ways 35 in the carriage 29 for coactsl with adjustable stop `screws 31:'and 38 ony ,y

the carriage 29 vto limit the transverse movement of the tool holder in -both directions. The

tool holder 34 is hydraulically actuated by a piston 39 connected thereto by a rod 40 and itted for reciprocation in a cylinder 4| xed to the back car- Y riage 29.

Driving liquid is supplied to the several cylinders I1, 32, 'and 4| from a variable delivery pump 42 which is placed under the joint control of the two control drums I9 and 20 hereinabove referred to. The pump 42, diagrammatically indicated in Figs. 1, 2, 3 and 5, is of a type fully described in my copending application Serial No. 407,921, illed November 18, 1929 (Patent No. 1,966,814). It will be suihcient here to state that this pump is driven at constant speed through appropriate means such as a pulley-43, and delivers liquid through a pipe 44 to a main distributing valve 45 at a rate dependent upon the position of a control stem 46 (Fig. 5). This pump receives its supply of liquid through a pipe 41 from an auxiliary gear pump 48 which in turn Areceives its supply 53 and 54 connected with the valve 45 at oppositev sides of the delivery pipe 44 constitute two sides of the hydraulic motor circuit. A pipe 55 leading from the distributing valve leads through a check valve 56 to the delivery pipe 44. l

A pair of opposed springs 51 and 58 yieldably retain the distributing valve in the intermediate or neutral position of Fig. 5, in which position pipe 44 is connected to pipe 5I and the pump circuit is by-passed. A piston 59 which responds to pressure supplied through a pipe 60 functions to shift the valve one step toward the left to thereby connect pipe 44 with pipe 53 and to connect pipe 54 with exhaust pipe 5I to thus set up a flow in the motor circuit in one direction. In this'position of thevalve pipe50 is blocked from pipe 55 andthe motor circuit is supplied from the main pump alone. A second piston 6| which responds to pressure supplied through a pipe 62 functions to shift the valve 45 further to the left, in which position pipe 44 is still connected with pipe 53 and pipe 54 with pipe 5|, but pipe 50 is then connected through. pipe 55 with pipe 44 to thereby add the discharge from the gear pump to that of the main pump, and thus increase the flow in the motor circuit. The piston 6I also functions under pressure supplied through a. pipe 63 to shift the valve .into a right extreme position, in which position pipe 44 is connected with pipe 54 and pipe 53 with pipe 6I so that the flow in the motor clrcuitis reversed, and in this position pipe 60 is again connected through pipe 55 with pipe 44 so that the flow in the motor circuit is increased by thus adding the discharge from the gear pump to the 'flow in pipe 44. The several pipes 60, 62, and 63 are controlled by a rotary pilot valve 64 which is actuated and controlled by the stem 46.

The arrangement is such that with the stem 46 of the distributing valve in the intermediate position of Fig. 5 none of the pipes 60, 62, or 63 contain pressure and the distributing valve assumes at a rate corresponding to the rate of ow in pipe 44. Further movement of the stem 46 toward the right effects a gradual increase in the rate of ow in pipe 44 and pipes 53 and 54 up to the maximum displacement of the main pump and further movement in the same direction opens the pipe 62 to gear pump` pressure to thereby shift the valve 45 into a left extreme position so as to connect pipe 50 from the gear pump to pipe 44 and thereby further increase the flow in pipes 53 and 54. Upon shifting the stem 46 toward the left from the position of Fig. 5 pipe 63 is opened to gear pump pressure to thereby shift valve 45 into a right extreme position and thus set up a rapid flow through pipes 54 and 53 in a reverse direction. Since the pump including the control stem 46, pilot valve 64. and distributing valve 45 are all fully described in my co-pending application last above mentioned, a further explanation thereof at this time is deemed unnecessary.

In this instance the control stem 46 is actuated hydraulically by a piston 65 working in a cylinder 66. The piston 65 is energized by gear pump pressure supplied through a pipe 61 connected with pipe 50 and controlled by a pilot valve 68. The valve'68, shown in Figs. 5 and 6, comprises a housing having a longitudinal bore therein. A pipe 69 from the left end of the bore connects with a drain pipe 10, and a pipe 1I 'from the right end of the bore also connects with drain pipe 10. Pipe 1I contains a needie valve 12 for regulating the rate of flow therethrough. A plunger having two spaced heads 13 and 14 is closely fitted for lengthwise movement in the bore. A pipe 15 connected with the right end of cylinder 66 communicates at all times with that portion of the bore between the heads 13 and 14. Pressure pipe 61 leads to an annular grove 16 in the bore controlled by head 13. An annular channel 11 wider than the head 14 but controlled thereby connects with a pipe 18 communicating with the left end of cylinder 66. With the plunger of pilot valve 68 in the right position of Fig. 5 pressure pipe 61 is blocked by head 13 and pipes 15 and 18 are in open communication through the channel 11 so that there is no pressure in either end of cylinder 66 and piston 65 is freely movable therein. But when the plunger of valve 68 is inthe left position of Fig. 6 pipe 15 is exposed to the pressure pipe 61 and pipe 18 is connected to the pipe 1I so that the piston 65 is then forced toward the left at a rate dependent upon the setting of the needle valve 12.

The pilot valve 68 is placed under the control of the control drum 20 hereinabove mentioned and for this purpose the plunger thereof is connected to a rod 19 having a pair of stops 80 and 8| fixed thereon. Stop 80 is arranged to coact with any one of a series of stops 82 each adjustably xed to one of the six sides of the control drum. The arrangement is such that upon each forward advance of the main carriage- I4, one of the stops 82 moving with the carriage and drum, engages the stop so as to shift the plunger of valve 68 into the left position of Fig. 6. The adturn movement of the main carriage I4 a collar 75 limits, the downward throw of the arm 99.

83 on the right end of drum 29 engages the stop 8| to thereby return the plunger of valve 68 to the right 'to the position of Fig. 5 and thereby destroy the pressure in the right end of the cylinder 86 and connect the opposite ends thereof through J The control stem 45 is also mechanically actuated through. mechanism now to be described under the control of the drum i9 and for this purpose the piston 65 is provided with a tail rod 84 which is connected through links 85 and 86 to the depending arm 81 of a bell-crank rock- 491| and with an appropriate iixed bracket 91 yieldably urges the bell-crank to rock clockwise so as to depress the cam roller 99. An adjustablestop screw 98 threaded in a iixed'bracket 99 In each of the six rotative positions of this drum |9 one of the cams 95 coacts with the roller 99 to adjust the piston 65 and thereby regulate the pump 92 and distributing valve 95 and thus regulate the rate of movement of the main carriage |9 during each advance and return movement thereof in a manner to be later described.

. Pipe 59 constituting one side of the hydraulic circuit leads from the distributing valve 95 to the left end of the driving cylinder of the main carriage. Pipe 59 contains a spring loaded valve |99 which is set to open at a low pressure and which offers a predetermined resistance to the How of liquid to the cylinder 1|.V A check valve 99| connected across the resistance valve |99 opens freely in the opposite direction so as to permit a free flow of liquid from the cylinder l1. Pipe 59 constituting the other side of the hydraulic circuit leads from the right end of cylinder to the distributing valve 95. This pipe contains a choke coil |99 of small bore tubing adjacent the cylinderlwhich restricts the escape of liquid therefrom. A pipe |99 controlled by the piston l5 connects with the pipe 53 beyond V the choke coil |99 so as to by-pass the choke coil its stroke.

|99 which prevents a direct flow therethrough to i and thus permit a free escape of liquid from the right end of the cylinder. ll until blocked by the piston as the piston approaches the right end of Pipe 53 also contains a check valve the cylinder A pipe |95, connected with pipe 59 between the cylinder and choke coil |99, cooperates with a pipe |95, connected with pipe 59 between the check valve |99 and distributing valve l|5`to provide a by-pass connection around the check valve and choke. These pipes |95 and |95 are controlled by a valve |99 to be later described. A check valve |98 within the pipe |95,

prevents flow therethroughfromthe cylinder i1. A branch pipe |99 connected to. pipe 54 between the resistance valveA I 99 and the distributing valve 45 leads to the valve |91. The valve |91 also controls communication between pipe |96 and a pipe ||9 leading to the right end of cylinder 32 and between pipe |99 and a pipe leading to the left end of cylinder 32. A pipe ||2 forms a direct connection between pipes ||9 Yand |95 and includes a spring loaded resistance valve H3 which offers a predetermined resistance to flow therethrough from pipe ||9 and prevents flow in the opposite direction.

, Valve |91 shown in section in-Figs. 5 and 7 comprises a. housing containing a longitudinal.

bore whose opposite ends are in open communication through a pipe ||4 connected to the drain pipe 19. A plunger having three. spaced piston heads H5, ||6 and is closely tted to slide longitudinally of the bore. Pipe |96 communi- .cates at all times with the spacebetweenthe heads ||5 and ||6. Pipe |95 communicates with an annular groove ||8 in the bore and controlled `by head H5. Pipe ||9 communicates with a similar groove ||9 controlled by head ||6. Head ||1 controls two grooves |29 and |2| which communicate with pipes and |99, respectively, A spring |29 yieldably maintains the Valve plunger in the left position of Fig. 5 in which position pipe |95 is open to pipe |95 so that liquid'is free to flow from pipe 53 through these pipes to the right end of `cylinder' to thereby advance the piston i5 and main carriage |9 toward the left and in this position head |9 blocks pipe |9 and head blocks pipes and |99. The plunger of valve |9`|| is movable into the right position of Fig. '7 by a rod |99 connected to one arm |99 of a bell-crank rockably supported on a stub shaft |99 during an advance of the main carriage 9 the plunger oi valve |99 is shifted into the positionof Fig. 7 in which position pipe |95 is blocked, pipe |96 is connected with pipe H9, and pipe |09 is connected with pipe A pipe |99 leading from a point adjacent the left end of cylinder 99 and controlled by piston 39 connects with the forward end of cylinder 9|. A pipe |99 connecting pipe ||9 with the rear end of cylinder 9| contains a resistance valve |3| which offersa predetermined resistance to the flow of liquid to the cylinder 9|. |39 connected across the valve |3| permits a free ow through pipe'li99 from the cylinder 9|.

As previously pointed out the stop 99 lcoacts with one of the stops 99 on thedrum 99 to automatically reverse the movement of the main carriage i9 and thus approximately determine the extent of advance thereof. The limit of advance may be determined with extreme'accuracy when required by the provision of a positivestop in the form of an upright abutment member |33 adjustably fixed to one of the Ways 3 and arranged to coact with one or another of the stop members |39 removably fixed to the sides of the turret i9. The arrangement is such thatwhenever the turret |8 is so positioned as to align one of the stop members |39 thereon with the abutment member |33 the main carriage I9 advances until arrested by|"engagement 'of member |34 against member |33 'to thereby accurately limit the advance thereof. This occurs immediately after one of the stops 82 in the drum 29 has engaged thestop 89 on rod 19 and shifted the pilot A check valve termines the rate at which liquid escapes from the left end of cylinder 66 it governs the rate oi.' movement of piston 65 and thus determines the interval of time required to effect complete reversal. 'I'his interval of time is ordinarily such as to insure the engagement of stop |34 against stop |33 and to retain the main carriage in this advanced position until the tool carried thereby has had an opportunity to smooth off the face of the cut.

'I'he lathe equipped with the'system described is capable of automatically executing a complete cycle involving six advance movements of the main carriage, the operating characteristics during each advance being predetermined by the rotative position of theturret I8 during that advance. Asvpreviously pointed out the turret I8 is automatically indexed to a new position at the end of each return stroke of the main carriage by a known type of mechanism such for instance as that described in the copending application first above mentioned, and each of the three control drums I9, 20, and 28 which are driven by the turret also assumes a new position at the end of each return stroke.` The several cams 95 on the drum I9 come into position successively to regulate the rate of flow in pipes 53 and 54 during each advance of the main carriage, the vseveral stops 82 on the drum 20 come into position successively to effect reversal of movement of the main carriage at the end of the advance thereof, andthe cam or cams |28 on the drum 28 are brought into position to render the tool holder 34 active at a predetermined stage of the cycle.

Each of the cams 95 on the drum I9, except the first cam of the series, is provided with a relatively high nose portion |35 whichupon each rotation of the drum (the carriage I4 being at the end of a return stroke) acts upon the cam roller 94 to elevate the same into the position of Fig. 4 and thereby shift the control stem 46 toward the right to start the main carriage on its next advance stroke. The nose portion |36 on the first cam 95 of the series is relatively low so that when it is rotated into position at the end of the last return stroke it acts on the roller 94 to shift the same into the intermediate position of Fig. 5 to thereby return the piston 65 and control stem 46 into the neutral position of that figure and thus bring the machine to rest.

To start an operating cycle the attendant depresses the hand lever |31 to thereby lift the cam roller 94 from the nose |36 of the cam 95 and to force the control stem 46 into its right extreme position, in which position the valve 45 assumes a left extreme position and the pump 42 delivers liquid at a maximum rate through pipe 44, through the distributing valve 45, and through pipes 53, |06, and |05 to the right end of the cylinder I1 to thereby cause the piston I5 and main carriage I4 to advance toward the work at a rapid rate. In this position of the control stem the discharge from the gear pump 48 is added to the discharge from the main pump so that the speed of advance of the main carriage is at a maximum. The attendant holds the hand 1ever |31 in this depressed position until the high portion 95' of the cam has advanced beneath the roller 94. The carriage then continues to advance at this rapid rate until the roller 94 passes onto a depressed portion 95" -of the cam and thus shifts the stem 46 slightly toward the left from its right extreme position to thereby block Vthe discharge from the gear pump from the pipe 44 so that thenafter the pipe 63 is supplied from the main pump alone, and the rate of advance of the carriage I4 is correspondingly reduced. This occurs just before a tool on the turret I8 engages'the work. Since further movement of stem 46 toward the left effects a gradual reduction in the rate of discharge from the mainv pump the rate of advance of the carriage |4 is made to correspond to the pattern of the cam. Each cam 95 is so patterned as to effect the proper rate of advance for the particular operation to be performed. In this instance the rear end of the depressed portion 95" is shown further depressed to thereby further reduce the rate of advance of the carriage as the cut approaches completion.

During this advance the plunger of pilot valve 68 remains in the right position of Fig. 5, so that pipes 15 and 18 are connected and the piston 65 is free to move in response to movement of the cam roller 94, until the stop 82 on drum 20 has engaged stop on rod 19 and shifted the plunger of this valve toward the left. As this plunger moves toward the left, head 14 thereof blocks communication between pipes 15 and 18 and establishes communication between pipe 18 and pipe 1I and between pressure pipe 61 and pipe 15. This occurs as the roller 94 is passing beyond the end of its coacting cam 95, and the piston 65 and control stem 46 are shifted into a left extreme position to thereby direct the liquid from pipe 44 into pipe 54 to thus reverse the flow in the hydraulic circuit and consequently start the main carriage |4 on a return stroke. This movement of piston 65 is transmitted to the arm 92 to cause it to lower against the stop 98, so that during the return stroke the cam roller 94 is disposed below its coacting cam 95. When it is desired to accurately limit the advance of the main carriage I4 the needle valve 12 is partially closed to thereby redce'the rate of movement of pislton 65 toward the left and thus delay actual repipe 61 through pipe 15. As the carriage approaches the end of its return stroke the turret I 8 is indexed into a new position and drum |9 is rotated correspondingly to lift the next cam 95 into position. The nose |35 on this new cam acts on the cam roller 94 to elevate the same and the arm 92 into the position of Fig. 4, and to thereby compress the spring 9| contained within the telescopic connection between the links 85 and 86.

Thenafter the plunger of the pilot valve 68 is returned to the right position of Fig. 5 by the action of collar 83 on stop 8|, to thereby again connect pipes 15 and 19 and permit the piston 65 and control stem 46 to move to their right extreme position under the action of spring 9|. This action reconnects pipe 44 with pipe 53 and the carriage begins its next advance under the control of the new cam 95.

The main carriage I4 thus continues to advance and return continuously until on the last return stroke the last cam 95 of the series is rotated into position and the nose |36 thereof returns the cam roller 94 and consequently the piston 65 and control stem 46 into intermediate or neutral position of Fig. 5 to thus bring the machine to rest.

One or more of the advance and return strokes 75 of the main carriage Il may be idle strokes with none of the tools in 'cutting position, executed for the purpose of indexing the turret I8 and for effecting and controlling the movements oi the tool holder 34. The tool holder 34 is brought into action whenever a cam |20 is brought into alignment with the roller |21 by indexing of the drum 20. When the cam |28 is thus aligned and advanced by the next advance of the main carriage it acts upon the roller |21 to shift the plunger of valve |01 into the position of Fig. 7 to thereby block the pipe |05 and connect the pipe |06 with pipe |0 so that the liquid delivered through pipe 53 is directed into the right endof cylinder 32 to thereby shift the piston 32 and back carriage 20 into theleft extreme position of Figs. 1' and 5, and thus properly align the tool T with the end face of the work W. When the piston stalls against the left end of the cylinder 32, the pressure in the right end thereof immediately rises and opens the resistance valve |3|, so that liquidA 'tool holder 3| advances at a rate corresponding to the rate of pump delivery. The rate of pump delivery at this time is of course determined by the particular cam 05 which is then in engagement with the roller 03. During this advance of the piston 30 'and tool holder 30 liquid escapes from the forward` end. ofcylinder 0|-, through pipe |00, check valve |00and pipes |00, and 50 to the distributing valve 05.

This advance of the tool/holder 00 continues until arrested by impingement of stop 30 thereon against the stop screw 3l,..-v When this occurs the pressure in pipe |0 immediately rises sumciently to open the resistance valve |3 so that thereafter liquid ilows through pipes |||i, |05, and 50 into the rear end of cylinder to advance the piston i5 and main carriage |0. `0.5 the main carriage thus advances thetool holder 30 remains at rest until the hydraulic circuit is reversed, in the manner previously described, by the action of one of the stops 02 against the stop 00 yon rod |0. When this reversal occurs liquid from pipe 00 is -directed through pipes 50, |00, and to the left pipe |20- into the forward end of cylinder 0| to thereby shift the piston 30 and tool-holder 00 rearwardly, liquid escaping from the rear end of cylinder through pipes |30, ||0, |06, and 50 to and through the valve 05. v

This return movement of the carriage 30 continuesuntil arrested by engagement of stop 0.0 against stop screw 30, at which time the pressure in pipe 50 rises sufciently to open the resistance valve |00, and the liquid delivered from pipe M is thereafter directed through this valve into the left end of cylinder |1, so as to drive the piston indexed with a new position the drum 28 is rotated thereby to shift the cam |28 out of alignment with roller |21 and the carriage'20 and tool holder 34 remain inactive until a cam |28 is again aligned with the roller |21.

Each returnstroke of the main carriage I4 is ordinarily executed at a. rapid rate and to avoid undue shock and jar by a sudden arresting thereof provision is made for reducing the speed of movement thereof during completion of each return stroke. Thus during thebeginning of each -return stroke liquid escapes freely from the right end of cylinder I1 through the pipe |03 to pipe 53 at a point beyond the choke coil |02. But as the piston |5 approaches the end of its return stroke it blocks pipe |03 so that thereafter liquid can escape from the right end of the cylinder through the choke coil |02 only, the check valve |00 'preventing escape through pipe |05. The movement of the piston |5 is thus suddenly checked by a dash-pot action so as to cushion the return stroke of the carriage. The pipe |00 is preferably so positioned as to be blocked by the piston i5 just prior to the engagement of the bar 0 against the stop 0, so that this cushioning or checking of .the return stroke of the carriage occurs prior to theoperation of the turret indexing mechanism. Thereafter as the carriage |0 continues to move slowly toward the right the ratchet element 0 is rotated counter-clockwise by the reaction of the stop 0 on the bar 0 to thereby index the turret into its next position. During the nent `advance stroke of the carriage the bar 0 and element 0 execute an idle movement under the action of spring 5.

`Various changes may be made in the embodiment of the invention hereinabove specifically deadvantages of the invention as defined in the appended claims.

l. lin a machine tool or the like the combination of a support, a carrier movable thereon, hydraulically actuated means for driving said carrier, a variable delivery-pumping means, a hydraulic circuit fed by said pumping means for driving said means, a control element, means responsive to movement of said element through va limited range for effecting a gradual variation in the rate of delivery of said pumping means to therebyregulate the rate of movement of said carrier, additional means responsive to movement of said element beyond said range for effecting an abrupt increase in the rate of flow in said circuit to thereby increase the rate of movement of said carrier, and means controlled by the movement of said carrier for controlling said element. 2. In a machine tool or the like the combination of a support, a carrier movable thereon, hydraulically actuated means for driving said carrier, a variable delivery pump, a hydraulic circuit fed by said pump for driving said means, a control element, means actuated by said `element for varying the rate of pump delivery to thereby regulate the-'rate of flow in said circuit, fluid actuated means controlled by said element for reversing the direction of flow in said circuit, and means actuated by movement oi' said carrier for controlling said element.

3. In a. machine tool or the like the combinafed by said pump for driving said means, a. control element, means actuated by said element for varying the rate of pump delivery to thereby regulate the rate of i'low n said circuit, a uid actuated valve controlled by said element for reversing the direction of flow in said circuit, and means controlled by said carrier for controlling said element.

4. In a machine tool or the like the combination of a support, a carrier 'movable thereon, hydraulically actuated means for advancing and retracting said carrier, a reversible hydraulic circuit for energizing' said means, an auxiliary carrier, a second hydraulically actuated means for advancing and retracting said auxiliary carrier, and valve mechanism controlled by said ilrst named carrier independently of said auxiliary carrier for rendering said rst named hydraulically actuated means inactive and connecting said second hydraulically actuated means in .driving relation with said circuit.

5. In a machine tool or the like the combination of a support, a carrier movable thereon, hydraulically actuated means for advancing and retracting said carrier, a reversible hydraulic circuit for energizing said means, an auxiliary carrier, a second hydraulically actuated means for advancing and retracting said auxiliary carrier, a third hydraulically actuated means for shifting said auxiliary carrier transversely of lthe direction of advance thereof, means controlled by said carrier for interrupting the action of said first named hydraulically actuated means and connecting said second and third hydraulically actuated means in driving relation with said circuit, and means automatically operable to determine the sequence of operation of said second and third hydraulically actuated means.

6. In a machine tool of the like the combination of a support, a carrier movable thereon, hydraulically actuated means for advancing and retracting said carrier, a reversible -hydraulic circuit for energizing said means, and auxiliary carrier, a second hydraulically actuated means for advancing and retracting said auxiliary carrier, a third hydraulically actuated means for shifting said auxiliary carrier transversely of the direction of advance thereof, means automatically operable to interrupt the advance of said carrier and to connect said second and third hydraulically actuated means to said circuit to thereby operate said auxiliary carrier duringthe inactive condition of said rst named can'ier, means automatically operable to renew the advance of said iirst named carrier, means controlled by said iirst named carrier for reversing said hydraulic circuit, and means automatically operable to determine the sequence of operation of said three hydraulically actuated means after reversal of said circuit.

" WALTER FERRIS.

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