US2170494A - Grinding machine - Google Patents

Description

Aug. 22, 1939. HUERNST ET AL GRINDING MACHINE 6 Sheets-Sheet 1 Filed Oct 20, 1936 ATTORNTY.

Aug. 22, 1939. H. ERNST ET AL GBINDING MACHINE Filed Oct. 20, 1936 6 Sheets-$heet 2 ATTORNEY.

6 sneets sneez 3 Zia]? H. ERNST ET AL GRINDING MACHINE Filed Oct. 20, 1935 INVENTOR. fim" ffl/Xfi" aim/1M1 ATTORNEY.

Ila-5 Aug. 22,- 1939. H E NST ETAL 2,170,494

GRINDING MACHINE Filq on; 20, 19:56 6 Sheets-Sheet 4 ATTORNEY.

Aug. 22, 1939. H. ERNST El AL 2,170,494

GRINDING MACHINE Filed Oct. 20, 1936 6 Sheets-Sheet 6 I flaw/$5241 Wm llllll. u ii] INVENTOR. fikm" fin.

A'I'I'ORNEY.

h k\- l-.-t i v @QQ w NM 0 RM 5 ANN kw QM mm v EN www a. a MN QM a? g mm v. uu Q Q \m m Q 3 R Q m Q Q Q. QWN a v v S N a v .Q, &w J \Qw mama Q0 \\N N .QN .QN Q v 5 m. a W M\ RR v \NN QNN QN N 7 Q Nk k n EN QN Q Q R v 5 RN 3 .& ww N w\ R g i Z Q 2N wm m .RN MM Na 7 \N Q1 Patented Aug. 22, 1939 UNITED STATES aim-194 GRINDING MACHINE- Hans Ernst, Cincinnati, and Albert H. Dali, Silverton, Ohio, assignors to Cincinnati Grinders Incorporated, Cincinnati, Ohio, a corporation-o! Ohio Application v(lctobcr 20, 1936, Serial No. 106.596

22 Claims.

This invention relates to machine tools and more particularly to improvements in the transmission and control mechanism thereof.

One of the objects of this invention is to provide an improved transmission and control mechanism which is especially adaptable for controlling the relative movements of a grinding wheel in a machine having capacity for relatively large work and in which the movements of the wheel must necessarily be relatively large.

Another object of this invention is to provide a transmissiion and control mechanism for the purposes described which is comparatively simple in construction, but which is capable of yielding all the desirable control eiiects necessary to the successful operation of a machine of the above character.

A further object oi this invention is to provide a transmission and control mechanism which is.

capable of yielding a plurality of ranges of feed rates, all in continuous succession, together with infinite variation throughout all ranges.

Other objects and advantages of the present invention should be readily apparent by reference to the following specification, considered in conjunction with the accompanying drawings forming a part thereof and it is to be understood that any modifications may be made in the exact structural details there shown and described, within the scope of the appended claims, without departing from or exceeding the spirit of the invention.

Referring to the drawings in which like reference numerals indicate like or similar parts: Figure 1 is a plan view of a machine embodying the principles of this invention. I

Figure 2 is an end elevation of the machine in the direction indicated by the arrows 2-2 .in Figure 1. s

'40 Figure 3 is an enlarged cross sectional view through the wheel slide showing the means for adjusting the wheel toward and from the work support.

Figure 4 is a cross sectional view through the 45 wheel head carried carriage taken along the line 4-4 of Figure 1 and showing the final driving means for traversing the carriage,

Figure 5 is a detailed section on-the line 5-5 of Figured showing the means for selecting be- 50. tween manual and powertraverse oi the wheel head and for selecting between the high and low source of feed rates.

Figure 6 is a detailed section on the line 66 of Figure 3 showing the means for clamping the cross slide to the traversing slide.

Figure 7 is a fragmentary view with parts broken away looking in the direction of the arrows 1--1 of Figure 6.

Figure 8 is a section on the line 8-8 oi Figure 2.

Figure 9 is a detailed section taken on the line 5 9-9 of Figure l.

Figure 10 is a detailed sectional view taken on the line i0l0 of Figure 9.

Figure 11 is a detailed view taken on the line H-ll of Figure 9. I 10 Figure 12 is a sectional view taken on the line l2l2 of Figure 11.

Figure 13 is a diagrammatic view of the transmission and control mechanism of the machine.

Figure 14 is a plan view of the guide plate as 10 viewed on line H-H of Figure 5.

Figure 15 is a detail view of the variable delivery pump control.

Figure 161s a. plan view of the control shown in Figure 15. 20

This invention has been illustrated in connection with a roll grinding machine of the type .shown in Figures 1 and 2 which consists oi. an

elongated fixed bed I0 on which is mounted a headstock ii and a tailstock l2, the latter of 25 which is adjustable toward and from the headstock for set-up purposes. There is also provided a pair of guideways i3 and I4 upon which is slideably mounted a traversing caniage. I! which, in turn, supports a transversely movable 30 wheel head carriage l6,

This invention is concerned with an improved transmission and control mechanism for controlling'the transverse movements of the wheel head and the feeding and traversing movements of as the carriage 85.

As shown in Figures 3 and 13, the cross slide I6 is actuated by a piston I! connected by a piston rod I8 to the slide l6 and .slideabl y mounted in a cylinder is. The opposite ends of this cylinder. are connected by channels 20 and 2| to ports 22v and 23 of a manually operable reversing valveil. This valve has a pressure port 25 connected to the delivery of a constant displacement pump 26 which has an intake 21 through which fluid is withdrawn from a reservoir, indicated generally by the reference numeral 28. The reversing valve 24 has an additional pair of ports 29 and 30 connected to a returnline 3|.

The plunger 32 of the reversing valve is connected by a crank 33 to an operating handle 3. When the plunger 32 is shifted to the right, as viewed in Figure 13, the pressure port 25 is connected to port 23 whereby fluid is delivered to.

one end of cylinder I! to cause the wheel head i l6 to move toward the work support and when the plunger 32 is shifted to the left of the posimoved by power.

grinding wheel for set-up purposes, and since, as

a matter of fact, each roll that is ground is usually of a diflerent size it becomes necessary to adjust the grinding wheel for practically every piece of work.

To insure, however, that thegrlnding wheel maintains a definite position with respect to the slide l5 and that there is no creepage due to the slight variations in pressure in the opposite end of cylinder I9, a clamping mechanism has been provided for securing the slide l6 to the slide 15.

The details of this clamping mechanism, which are more particularly shown in Figures 6, "I and 8, comprise a pair of pull rods 35 and 36 located on opposite sides of the V guide-way 31 and the are threaded to receive lock nuts 40. The lower upper ends of these rods pass through L-shaped clamping members 38 and 39 respectively and ends of these rods are connected to an equalizer bar 4| .which is adapted to be engaged in the middle by a pivoted clamping lever 42.

This lever, as shown in Figure '1, is pivotally mounted at one end on a fixed stud 43 and at the other end rotatably supports a cam 44 which is actuated by the ball-ended crank 45. The cam 44, which is circular, is eccentrically supported on the shaft 46 and when the parts are in the clamping position shown in Figure 'l, the largest radius of the cam engages the undersurface of the block 41, thereby holding the lever 42 downward which thereby applies pressure on the equalizer bar 4| and rods and 36 to cause the'clamping members 38 and 39 to hold the slide in a fixed position. The cam is moved into this position by the application of fluid pressure on the end of the piston 48 and the clamps are released by applying fluid pressure on the end of the piston .49. As shown, these pistons bear on' the ball-shaped crank 45, piston 48 tending to rotate the parts in a counter-clockwise direction and the piston 49 tending to rotate the parts in a clockwise direc-' tion. The pistons 48 and 49 are contained in cylinders 50 and 5| respectively and these cylinders are connected by channels 52 and 53 respectively to ports 54 and 55 of a reversing valve 56 having a central pressure port '51 and return ports 59 and 59 on opposite sides thereof. The plunger 60 of this reversing valve is urged by-a spring 6! in such a direction that the pressure port 51 is connected to the port 54 leading to cylinder 59 whereby the cross slide I6 is clamped to the traversing slide 15. Pressure is supplied to the port 51 from a branch line 62 which is supplied with fluid from the constant displacement pump 26. 3

It is, of course, obvious that the clamping mechanism should be released before the slide is moved and to this end means have been provided whereby the lever 34 will actuate the reversing valve of the clamping control mechanism, before it finally shifts the plunger 32 into a position to effect pressure connections to the cross slide actuating cylinder l9. This mechanism comprises a lever 63 having one end pivoted at 64 and the other end engaging the plunger 60. An intermediate V-shaped portion 65 of the lever is adapted to engage a notch 66 .in the periphery of a plate 61 fixed for movement with the lever 34. The notch permits the spring 6| to shift the plunger 60 into the position shown in Figure 13, whereby pressure is connected to cylinder 50. Upon movement of the lever 34 in either direction from the central position in .which it is shown, the lever 63 will be moved ,in a clockwise direction about its pivot 64 and shift the plunger 60 to the right and thereby causefluid pressure to be connected to cylinder 5| with a resultant release of the clamping. mechanism. As the lever 34 moves'to shift the plunger 69 it is also moving the reversing valve plunger 32, but this plunger has sufficient overlap with respect to its ports that appreciable movement may be efiected before pressure is connected into lines 20 and 2|. Since a certain time element is involved in effecting unclamping and to prevent dissipation of the pressure, which would happen if the operator moved the lever 34 quickly to either of its extreme positions, an interlock has been provided which limits the movement of the valve plunger 32 so that it will not attain an operative position until the clamping mechanism has been released.

This mechanism includes a notched plate 68 integrally connected for movement by the handle 34, and a spring-pressed'pawl 69 adapted to be held in engagement with said notch, the notch being of suflicient width to allow a certain amount of lost motion between the pawl and the plate whereby the lever 34 may be moved a sumcient amount to cause shifting of the reversing valve 60 to a clamp unlocking position while still preventing movement of the plunger 32 to a slide actuating position. The pawl 69 is pivoted at an intermediate point 10, and a fluid actuaated plunger 1| engages the other end of the pawl for withdrawing the same from engagement with the plate 68. The plunger 1| is slideably mounted in a cylinder 12 which is connected by a channel 13 to a port 14 located in the cylinder 5!. When the plunger 49 has'moved a sufficient distance to release the clamp, the channel 53 which supplies fluid pressure to cylinder 5|, is interconnected with port 14 whereby the fluid pressure will be connected to cylinder 12 to cause withdrawal of the pawl and permit further movement of the lever 34. Upon return movement of the lever 34 to its central position, the plunger 48 will be actuated to move the crank 45 into a clamping position, a cannelure 15 formed in the plunger 49 will interconnect port 14 with exhaust port 16, wherebya spring 69' may return lever 69 into an interlocking position and effect retraction of piston -1l.

Thus, the first part of the movement of the lever 34 from its central position shifts the reversing valve 60 into a position to cause unclamping of the slide by connecting pressure to line 53; and completion of the unclamping operation automatically releases the lever 34 for by clamping of the slide and resetting of the locking pawl.

In roll grindersit is desirable to have a transmission which is infinitely variable over a comparatively wide range, and with this requirement in view, a transinission and control mechanism 7 has been provided which will yield a minimum rate of approximately 1" travel of the slide per minute and a fast rate'of approximately 120" per minute, together with the feature of variation between these limits.

It is also desirable that this transmission be of a type which readily lends itself to manual operation.

A careful selection of the elements making up this transmission has been made, in view of the fact that a piston and cylinder type of motor does not readily lend itself to manual operation of the slide, and because an electric motor of the variable speed type is limited to a range of 1 to 3 so far as infinite variation of speed is concerned. The units of the transmission, therefore, consist of a variable delivery pump and a variable speed fluid motor, which makes it possible to obtain an infinite range from 1 to 20, which makes possible.

infinite variations of travel from 1" to 20" per minute of the slide. Additional variation is obtained by combining a constant delivery pump having an output equal to the maximum output of the variable delivery pump whereby the range may be increased to obtain infinite variation of rate from 20 to. 40" of travel a minute. In either of the above cases, the variable speed hydraulic motor is connected by reduction gearing to the final output, and 'by reducing this reductionby the factor 4, the first range is increased to yield infinite variation of rate over a third range from 40" to 80", and the second range increased to yield an infinite variation of rate .over a fourth range from 80" to 120" per minute and all in continuous succession.

The transmission and control mechanism for traversing the wheel head relative to the work support will now be described. The fixed bed 18 on which the guide ways I3 and I4 are mounted for supporting the carriage I5 is provided with a rack 18 which is engaged by a pinion 88, as shown in Figure 4, secured to the end of a vertical shaft 8|. The shaft 8| is journaled in the carriage I5 on anti-friction bearings and is rotated by a worm wheel 82 which is, in turn, driven by a worm 83 Referring to Figure 5, the worm 83 is supported on a shaft 84 which has mounted for free rotation thereon a pair of spur gears85 and 86, gear 85 being larger in diameter than gear 86. These gears are in constant mesh with gears 81 and 88 respectively keyed to shaft 88. This shaft is directly connected for rotation by an hydraulic motor 88. The gear train 81--85 effects in this case a rate reduction of four times that effected by train 8886, but it is to be understood that other reductions could be utilized.

The clutch 8| is. splined on shaft 84 intermediate gears 85 and 86 and has clutch teeth formed on opposite faces for engagement with simiarly formed clutch teeth on the opposing faces of the gears. Since the gear 85 is continuously driven at a slower rate than the gear" 86, and since the motor 88 can be driven at a plurality of rates it will be apparent that the clutch member 88 serves to select between a high series and a low series of feed rates,

The clutch 8| is shifted by a shifter fork 82 fixed on the shifter rod 83. The shaft 84 has a gear 84 fixed to the end thereof and adapted to be interengaged by a shiftable gear 85 for manual rotation of the worm 83. The gear 85 is splined on a shaft 86 to the end of which is secured a large sprocket wheel 81 and connected by a chain 88 to a sprocket pinion 88. This pinion is keyed to effect translation of the carriage I5.

The gear 85 is shifted by a fork I83 which is secured to a shifter rod I84. In order to prevent conflict between manual and power operation of the worm 83, the shifter rods 83 and I84 are arranged side by side and a common control lever I85 is provided, and provision made whereby this lever can only shift the clutch 8| or the gear 85 into an operative position at a time. In other words, the lever I85 is pivotally mounted at an intermediate point by means of a ballshaped portion I86 and a guide plate I81 is provided in which is formed a. slot I88 having a shape such as that shown in Figure 14. The lever I85 is moved laterally through the portion I88 of the slot to select which shifter rod is to be moved and is movable through the portion I I8 to shift the clutch 8| into either one of its two positions and through the portion I I I to shift the gear 85 into engagementwith gear 84.

Operating fluid is supplied to the motor 98 by a variable displacement pump 2 having intake and delivery ports H3 and H4 respectively which are operatively connectible by channels H5 and H6 to ports H1 and H8 of a stop valve H8. The plunger I28 of this valve is shown ina stop position in Figure 13, but when the same is shifted to the right of that position thecannelure I2I interconnects port 8 with port I22, and thereby through channel I23 to port I24 of a re-' versing vave 25. In addition the cannelure I26 interconnects port I I1 with port I21, thereby through channel I28 to ports I28 and I38 of reversing valve I25. The reversing valve also has a pair of ports |3I and I32 to which are connected channels I33 and I34 respectively through which fluid is supplied to the motor 88. when the reversing valve plunger I35 is in its right hand position, as shown, the pressure is delivered into channel I33 from the delivery port II 4 of the pump H2 and the fluid returning through channel I34 is returned by way of port I38, channel I28, ports I21 and I "of the stop valve and channel I I5 to the intake port 3 of the variable delivery pump. It wilbe seen that this is in effect a closed circuit with the intake and delivery ports of the pump connected directly to the two ports of the motor.

The reversing valve plunger I35 is power shifted by fluid operable pilot circuit comprising a pilot valve I36 having a pressure port I31 connected by channel I38 to the delivery channel 6 of the variable delivery pump II 2. Also, the pilot valve has a pair of return ports I38 and I48 which are connected .to channel I leading to the intake line II5 of the variable delivery pump. In

addition, the pilot valve has a second pair of ports I42 and I43 which are connected by chan-- nels I44 and I45 respectively to opposite ends of the reversing valve I25. When the plunger I46 of the pilot valve is in its right hand position, as shown in Figure 13, pressure from port I31 will flow to the left end of valve I25 shifting.

plunger I35 into its right hand position and when the pilot valve piunger I46 is shifted to the left, pressure from port I31 will then be delivered to the righthand end of valve I25, shifting plunger I 85 to its left hand position.

The pilot valve plunger I46 is connected by a bell crank I41, shown in Figure 12, to a vertical movable slide I48 in which is formed a slot for receiving one arm I49 of the bell crank. The slide I48 is provided with a T slot I50 to which maybe secured a pair of adjustable dogs II. The slide is guided by an elongated gib I52. on one side and a pair of short gibs I53 located on the other side.

Due to the extremely long traversing movement of the wheel head, mechanism has been provided for proportionately shortening this move ment so that it is unnecessary to provide a long dog carrying slot, and furthermore to make it possible to provide a tripping mechanism which may be self-contained in the slide. To this end a screw I54 is rotatably supported adjacent to and parallel to the dog carrying slide I48, and has threaded thereon a trip member I55 which has a projecting portion on one side adapted to engage the dogs I5I and a guiding portion I56 on the other side which is engaged by a gib I51 to prevent rotation of the nut member. I One end of the screw is operatively connected to a sprocket wheel I58 which is connected by a chain I59 to a sprocket pinion I60 secured to the upper end'of shaft 8|, as more particularly shown in Figure 4. It should now be apparent that as the shaft 8| rotates, it rotates the screw I54, causing the nut member I55 to travel along the screw. The front of the housing I6I in which this tripping mechanism is contained is provided with a door I62 on one side and supported on hinges I63 whereby the operator may have ready access to the dog carrying slide, butstill permitting the entire mechanism to be enclosed and protected. I

The pilot valve plunger I46 may also be shifted manually at will by means of the control lever I64 which is keyed to the shaft I65 to which, in

turn, is connected the bell crank I41. Thus, the

pilot valve may be shifted manually at will, or automatically actuated from they moving car- 'rlage. The stop valve plunger I is operated by the manual control lever I66 which is fixed to shaft I61 journaled in the upper .part of the casing I6I and provided on the lower end with a. crank arm I68 engaging a cross slot formed in the end of plunger I20.

Means have been provided for obtaining a tarry at each reversal of the wheel carriage and this mechanism is interposed between the direction control valve; I25 and the hydraulic motor 90.

The mechanism comprises a double resistance throttle valve I69 in which is contained a plunger I10. This plunger has a pair of annular grooves HI and I12 formed therein and adapted to lie opposite ports I13 and I14 respectively, which ports are connected by .channels I15 and I16 toopposite ends of a shuttle valve I11. The grooves HI and I12 are provided with tapered portions I18 and I19'which lie opposite ports I and I8I and serve to form variable hydraulic resistances. The ports I80 and I8I are connected to channels I33 and I34 which come from the reversing valve I25. Since the channels I33and I34 are alternately connected to pressure and exhaust it will be apparent that in the position of the parts shown and with pressure in line I33 that fluid will flow through port I80 and hydraulic resistance I18, groove I1I, port I13, and channel I15 to the left end of valve I11, while the opposite end is connected to exhaust. This means that the plunger I82 should be shifted to the right in the position as shown. When the re- It will now be seen that versing valve shifts, however, the pressure in line I34 must pass through the resistance I19 and eventually build up a pressure in the right hand end of valve housing I11 and the fluid in the other end must be forced outward through resistance I18. The amount of time that this will take will depend, of course, upon the value of the resstances I18 and I19. and these may be varied to obtain various lengths of tarry.

The mechanism for effecting this adjustment consists of a spring I83 which acts on one end of plunger I10 to shift it in a direction to reduce the valve of the hydraulic resistances and an adjustable pin I84 for limiting the movement. As shown in Figure 10, the pin I84 abuts the end of a crank I85 secured to a rotatable shaft I86. This shaft carries a forked lever I81 in the end of which is pivotally connected a nut I88 threaded on an adjusting screw I89. This adjusting screw has an operating handle I90 on one end whereby the screw may be rotated to variably position the stop pin I84. In order to insure that pressure built up in either channel I33 or I34 when the same is connected to pressure and to prevent operation of the hydraulic motor 90 until the proper amountof time has elapsed, the plunger I82 is provided with a pair of self-contained check valves, indicated generally by the reference numerals I9I and I92. The plunger I82 is provided with annular grooves I93 and I94 whereby when the plunger I82 is shifted to the right the groove I93 will interconnect port I95 with motor line I96 and when shifted to the left the groove I94 will interconnect port I91 with motor line I98. In other words, the pressure fluid delivered by pump II4 will pass through either groove I93 or groove I94. It will be noted that the ports I95 and I91 are connected to the channels I33 and I34 which lead from the reversing valve.

In addition, the plunger I 82 is provided with a second pair of grooves I99 and 200 which are always exhaust grooves. In other words, when the plunger I82 is in its right hand position the groove'200 receives the exhaust flow from the motor 90 through channel I98, and when the plunger is in its left hand position the groove I99 receives the exhaust flow from motor channel I96. The grooves I99 and 200 have cross bores 20I and 202 respectively formed therein which intersect longitudinal bores 203 and 204 respectively. The bore 203 is enlarged totreceive a spring pressed ball check 205 which is adapted to be opened when the groove I99 is in communication with motor channel I96, but which through port I95,'but when port I95 is a pressure port the incoming fluid cannot be forced past the check valve. The same construction is provided in the other end of the valve plunger whereby the exhaust. fluid may be passed from channel I98 to part I91 but when port I91 is a pressure port the fluid cannot escape past the check valve. with the parts in the position shown if the reversing valve be shifted to make port I9 a. pressure port, fluid would'not be able to pass the checkvalve into annular groove 200 which means that the pressure would rise and pass through the resistance I19 into the right hand end of valve I11 and continue to rise until the valve plunger I82 is shifted into its left hand position, at which time the groove I94 would then directly connect port I91 to motor line I98.

If no tarry is desired it will be apparent that as shown in Figure 12, which is attached to the.

the plunger I10 may be adjusted to its extreme left hand position whereby the shuttle valve plunger will immediately shift upon reversal in the direction of flow and without delay.

As previously mentioned; the variable delivery pump H2 has a certain range, and in order to increase this range and maintain the infinite variation feature, use is made of the constant delivery pump 26, which has adisplacement equal to the maximum displacement of the variable delivery pump, and the output of the constant displacement pump is combined with the other pump by'means of valve 201. In order to make the supply from pump 26 available for this purpose, when it is not being utilized for clamping purposes, an interlock 208, Figure 13, is provided, and this valve serves to connect channel 52 to channel 2| 1. It will be noted that when the plunger 2l3 of the interlock valve is in its left hand position, as shown, that the line 52 which is under pressure at this time .is connected to port 2I0, whereby the port 2| 2 of valve 20! becomes a pressure port and will remain a pressure port at all times when the cross slide is clamped.

The valve 208 is really connected across the lines 52 and 53; and has one end port connected by branch 203 to channel 52, and the other end port connected by a check valve 2 to line 53, whereby, when channel 52 is under pressure the plunger 213 will be shifted'to the left, as viewed in Figure 13; and when channel 53 is under'pressure the plunger 2 [3 will be shifted to the right. During normal operation of the machine, the plunger 2 I3 is in the position shown in Figure 13, with pressure existing in line 52. Whenthe reversing valve 56 is moved to a position to effect unclamping of the cross slide, it is necessary that the plunger 2l3 be immediately shifted to the right, which the'check valve 2 M permits, so that when pressure is reconnected to channel 52 the circuit will be' in a, condition to cause sufficient pressure to build up in channel 52 to operate the clamping mechanism. It is, therefore, necessary to prevent dissipation of pressure through the channel 2 I I, which might be connected to the reservoir at any time, and to this end, means have been provided for preventing immediate shifting of plunger 2l3 into its left hand position, consisting of the choke coil 2l5 and the valve associated with plunger H. i In other words, the plunger H has a cannelure 2|! which, when the plunger H has been retracted by'the spring 69' acting on the lever 69,- serves to interconnect port 2I6, to which the outlet of the choke coil 2 I 5 is connected, with the exhaust port 2 It. The choke coil and valve act as a delay means to prevent shifting of the plunger 2l3 until the slide has been securely clamped. When the plunger 2l3 has completed its shifting movement to the left it interconnects branchv line 209 to port H and channel 2| I, thereby rendering the output of the constant displacement pump available for use in the supply circuit for motor 90.

It will be noted that when valve plunger 2l9 is I to the right, as shown in Figure 13, the port 2l2 is connected by cannelure 220 to port 22f leading to the exhaust 1ine,222. This permits the constant delivery pump 26 to be by-passed to reservoir, but since the fluid must pass through the relief valve 223 it will be apparent that .the system will be maintained full of oil at a low pressure.

The plunger 2l9 is shifted by a crank arm 224 thesame time, a cannelure 230 interconnects a branch 23! of return line I28 to the return line 222. This is necessarybecause it must be remembered that the variable displacement pump is connected in practically a closed circuit to the hydraulic motor 90 and when the fluid from the constant displacement pump is added to one side of this closed circuit, there will be an extra quantity being returned to the pump H4 which cannot be accommodated. Therefore, this connection permits the excess fluid to be by-passed to reservoir through the check valve 223and thereby replenish the supply to the constant delivery pump.

In Figures 15 and 16, there is shown the means for controlling the displacement of the variable delivery pump H2, and this means comprises a cam 232 attached to the lower end of shaft 233 against which is adapted to bear the pintle 234 of the variable delivery pump. A handle 235 is secured to the upper end of shaft 233 whereby the-cam may berot-ated to vary the displacement of the pump.

As shown in Figure 16, a chart 236 is associated with the handle 235 upon which may be placed suitable indicia whereby the operator may determine the feed rate for any given setting of the controls. There may be four concentric arcs, with the indicia on the first are indicating the rates available when the constant displacement 1 pump 26 is disconnected from the circuit, and

with the output .of the variable displacement pump; the indicia on the third are indicating the rates available when the constant displacement pump has been disconnected fro-m the circuit and the clutch 9| is shifted into its right hand position as shown in Figure 5; and the indicia on the fourth are indicating the rates available when both pumps have been combined to supply the motor 90, and the clutch 9| is in its right hand position. It will thus be apparent that there are four ranges of speed and each range is a continuation of the preceding one and without steps.

There has thus beenprovi'ded an improved transmission and control circuit which is especially adaptable for machines of the roll grinding type having long traversing movements and in which is incorporated in simplified form mechanism for obtaining all the desirable control functions.

What is claimed is:

1. In a machine tool having relatively movable work and tool supports, the combination of transmission means for effecting saidrelative movement including an hydraulic motor operatively.

connected to one of said supports, a conduit-system for supplying actuating medium to the motor including a reversing valve, a variable delivery having intake and delivery ports connected to said reversing valve, and means ineluding a shiftable valve interposed in the system between said reversing valve and said motor, and responsive to shifting of said reversing valve, to-decelerate, stop, and accelerate in an opposite direction the moving slide.

2. In a machine tool having relatively movable work and tool supports, the combination of transmission means for effecting said relative movement including an hydraulic motor operatively connected to one of said supports, a reversing valve, a variable delivery pump havingintake and delivery ports connected to said reversing valve, means interposed between said reversing valve and said motor and responsive to shifting thereof to decelerate, stop, and accelerate in an opposite direction the moving slide, said means including a delay valve and a valve having self-contained check valves effective to build up a shifting pressure when the flow is reversed to said -motor .to cause a slow movement of the lastmentioned valve and thereby a tarry of said motor.

3. In a machine tool having relatively mov able work and tool supports, the combination of transmission means for effecting said-movement including an hydraulic motor, a reversing valve,

a variable delivery pump having intake and delivery ports connected to-said valve, means in said valve for connecting said delivery port for reversible'operation of said motor, a constant delivery pump, selectively operable means for connecting delivery of said constant displacement pump for combination with the delivery of said variable displacement pump for increasing the movement of said motor to a rapid traverse rate, a stop valve interposed in the delivery channel of said variable delivery pump and eflective to connect the same to the intake of said variable de'- livery pump, and means for simultaneously connecting the constant delivery pump output to reservoir.

, 4. In. a grinding machine having relatively movable tool and work supports and an hydraulic motor for effecting said movement, the combination of a tarry mechanism including a shiftable plunger having a pair of self-contained check valves, a pair of ports connected tosaid motor, a'second pair of ports alternatively connectible to intake and delivery ports of a variable delive y pump, said check valves being effective to pass return fluid from said motor and block delivery of fluid to said motor, and means responsive to the pressure of said blocked fluid to shift said plunger into a position by-passing said check valve when subject to pressure.

5. In a machine tool having a work support and a tool support, the combination with hydraulic means for effecting relative translation between the-supports including an hydraulic motor and a reversing valve therefor, of a tarry valve interposed between the reversing valve and the motor, said tarry valve including a shiftable plunger, a pair of ports connected to said reversing valve and adapted to be alternately subjected to pressure thereby, branch connections from each of said ports to the respective ends of said valve, saidconnections havingvariable resistancestherein, means in the valve responsive to reversal of flow therethrough to block the pressure flow to said motor, and simultaneously cause a slow increase in pressure on one end of said valve to effect shifting of the same, and means effective upon completion of said shifting movement to connect the pressure flow to said motor.

6. In a grinding machine having a work support and a grinding wheel support the combination of transmission mechanism for traversing one of said supports relative to the other at infinitely variable rates including a rotary hydraulic motor, a variable displacement pump, a constant first-named pump to produce a second range of speeds, and means to adjust said rate changer to produce a plurality of other ranges of speeds;

"7. In a grinding machinehaving a work support and a grinding wheel'support, the combination of a transmission .for effecting relative movement between the supports including a final drive shaft operatively connected to the moving support, a rotary hydraulic motor, different ratio gear trains continuously driven by said motor, a

plurality of pumps selectively connectible in different combinations to said motor to yield a plurality of rates of actuation thereof, a manual actuator for said final shaft, means to couple selectively said manual actuator to said shaft, means to couple selectively either of said gear trainsto said shaft, said last-named means also. being. operable to disconnect simultaneously both of said gear trains from said shaft, and a common control for all of said coupling means.

8. In a grinding machine having a work support and a grinding wheel support, the combination of a transmission for effecting relative movement between the supports including a final drive shaft operatively connected to the moving support, a rotary hydraulic motor, different ratio gear trains continuously driven by said motor, a plurality of pumps selectively connectible in different combinations to said motor to yield a plurality of rates of actuation thereof, a manual actuator for said final shaft, means to couple selectively said manual actuator to said shaft, means to couple selectively either of said gear trains to said shaft, said last-named means also being operable to disconnect simultaneously both of said gear trains from said shaft, a common control lever for all of said coupling means, and an interlocking guide plate for said lever whereby when said manual actuator is connected to the final shaft, said motor will be disconnected therefrom and vice versa.

9. In a grinding machine having relatively movable tool and work supports and a fluid operable motor for effecting said movement in opposite directions, the combination with a pump for supplying fluid to said motor and a reversing valve, of a tarry mechanism including a shiftable plunger having a pair of self-contained check valves, a pair of motor channels, a second pair of channels adapted to be reversibly connected by said valve to the output of said pump, means interconnecting said plunger with all of said channels whereby said check valves are effective to pass return fluid from said motor and block delivery of fluid to said motor upon shifting of said reversing valve, .andmeans movable in response to the pressure of said blocked fluid to shift said plunger into a position rendering said check valves ineifective.

' 10. In a machine tool having a work support and a grinding wheel support, the combination of an hydraulic circuit for effecting relative movement between the supports including a fluid oper- 76 able motor operatively connected to the moving support, a variable delivery pump having intake and delivery channels connected thereto, a stop valve for interconnecting said channels to stop said motor, a reversing valve having pressure and return ports adapted to be separately connected to said pump channels by said'stop valve, variable automatic tarry mechanism interposed in the circuit connecting said reversing valve to said motor, and a pilot valve and control circuit for controlling the shifting of said reversing valve.

11. A machine tool having relatively movable work and tool supports, the combination of transmission means for effecting said movement including a' hydraulic motor, an actuating pump therefor and means for controlling the actuation of the motor by the pump including a pilot valve, a reversing valve operable by the pilot valve, an auxiliary reversing valve coupled with the first mentioned reversing valve and actuable thereby for determining the ultimate coupling of the actuating fluid from the pump to the motor, and an adjustable tarry mechanism coupled with said second reversing valve for controlling the rate of movement thereof.

12. A machine tool having relatively movable work and tool supports, the combination of transmission means for effecting said movement including a hydraulic motor an actuating pump therefor and means for controlling the actuation of the motor by the pump including a pilot valve, a reversing valve operable by the pilot valve, an auxiliary reversing valve coupled with the firstmentioned reversing valve and actuable thereby for determining the ultimate coupling of the actuating fluid from the pump to the motor, an adjustable tarry mechanism coupled with said second reversing valve for controlling the rate of movement thereof, and additional means for diverting the flow from said pump as respects said motor and valve mechanisms.

13. In a machine tool embodying a support and a plurality of members movable thereon with respect thereto, transmission means for efiecting movement of the supports including-hydraulic motors individual to the respective supports, a closed circuit including a first fluid pump individual to one of said motors for controlled actuation thereof, a second hydraulic pum, and means for selectively coupling said pump with'either of said motors, said means including discharge con- ;dults individual to the respective pumps, and valve means for coupling the respective conduits and simultaneously establishing a reservoir con nection for said first motor whereby the two pumps may be additively employedior actuation of one of said motors.

1 4. In a machine tool embodying a support and a plurality of members movable thereon with respect thereto, transmission'means for efiecting movement of the-supports including-hydraulic motors, individual to the respective supports, a closed circuit including a first fluid pump individual to one of said motors for controlled actuation thereof, a second hydraulic pump, and means ior selectively coupling saidpump with either of said motors, said means including discharge conduits individual to jthe respective pumps, and valve means for coupling the respective conduits and simultaneously establishing a reservoir connection for said first motor whereby the two pumps may be additivelycmployed for actuation of one ofsaid motors, and"selec'or means for rendering either or both of said pumps ineffecthe i'or actuation of said motors.

15. In a machine tool having relatively movable work and tool supports, means for clamping one of said supports and hydraulic actuators for effecting movements and clamping of the supports, means for effecting controlled hydraulic actuation'of said parts including a hydraulic pump selectively coupled with said support motors and operatively associated with the clamp mechanism, a plurailty of reversers individual to the motor and clamp mechanisms, a first interlock mechanism between the clamp control reverser and one of the motor reversers for determining the sequential operation of said parts, conduit means extending from the pump output to the second motor reverser, and a hydraulic interlock operatively associated with one of the first-named reversers for determining the flow through the conduit to said last-named reverser.

16. In a machine tool having relatively movable work and tool supports, means for clamping one of said supports and hydraulic actuators for effecting movement and clamping of the supports,

means for effecting controlled hydraulic actua- 1 second motor reverser, a hydraulic interlock operatively associated with one of the first-named reversers for determining the flow through the conduit to said last-named reverser, a first tarry mechanism for determining the flow condition in said interlock controlled conduit, and a second tarry mechanism for determining the time lag in directional reaction of the fluid transmitted by the conduit on the second support shifting motor in response to given adjustments of its reverser.

17.- A machine tool having relatively movable work and tool supports including means for shifting one of said supports and means for clamping said support against shifting movement, a first hydraulic motor for effecting shifting of the support, an additional hydraulic motor mechanism for controlling the clamp, and a hydraulic control and actuation system for said parts including a source of hydraulic fluid, a first reverser for coupling the hydraulic medium to actuate the support in reverse directions, a second reverser coupling the hydraulic fluid for movement of the clamp into engaging or releasing position, a single actuator controlling the movement of both reversers, an interlock between said reversers whereby coupling of hydraulic medium for actuation of the support is prevented when the clamp is engaged, and a delay mechanism for determining the sequential operation of the reversers by their common actuator.

18. A machine tool having relatively movable work and tool supports including means for shifting one of said supports and means for clamping said support against shifting movement, a first hydraulic motor for effecting shifting of the support, an additional hydraulic motor mechanism for controlling the clamp, and a hydraulic control and actuation system for said parts including a source of hydraulic fluid, a first reverser for coupling the hydraulic medium to actuate the support in reverse directions, a second reverser coupling the hydraulic fluid for move-.

ment of the clamp into engaging or releasing position, a single actuator controlling the movement of both reversers, an interlock betweensaid reversers whereby coupling of hydraulic medium for actuation of the support is prevented when the clamp is engaged, a delay mechanism for determining .the sequential operation of the reversers by their common actuator, a second shiftable support, a hydraulic motor for actuation thereof, and means for conditioning the hydraulic circuit by way of one of said reversers whereby the hydraulic actuating medium is rendered available for actuation of said second support shifting motor. a

19. A machine tool having relatively movable work and tool supports including means for shifting one of said supports and means for clamping said support against shifting movement, a first hydraulic motor for effecting shifting of the support, an additional hydraulic motor mechanism for controlling the clamp, and a hydraulic control and actuation system for said parts including a source of hydraulic fluid, a first reverser for coupling the hydraulic medium to actuate the support in reverse directions, a second reverser coupling the hydraulic fluid for movement of the clamp into engaging or releasing. position, a single actuator controlling the movement of both reversers, an interlock between said reversers whereby coupling of hydraulic medium for actuation of the support is prevented when the clamp is engaged, a delay mechanism for determining the sequential operation of the reversers by their common actuator, a second shiftable support, a hydraulic motor for actuation thereof, means for conditioning the hydraulic circuit by way of one of said reversers whereby the hydraulic actuating medium is rendered available for actuation of said second support shifting motor, and an additional serially arranged reversing mechanism in said circuit for determining the direction of actuation of said second support motor.

20. A machine tool having relatively movable work and tool supports including means for shifting one of said supports and means for clamping said supportagainst shitting movement, a first hydraulic motor for efiecting shifting of the support, an additional hydraulic motor mechanism for controlling the clamp,- and a hydraulic control and actuation system for said parts including a source of hydraulic fluid, a first reverser for coupling the hydraulic medium to actuate the support in reverse directions, asecond reverser coupling the hydraulic fluid for movement of the clamp into engaging or. releasing position, a single actuator controlling the movement of both reversers, an interlock between said reversers whereby coupling of hydraulic medium for actuation of the support is prevented when the clamp is engaged, a delay mechanism for determining the sequential operation of the reversers bytheir common actuator, a second shiftable support, a hydraulic motor for actuation thereof,' means for conditioning the hydraulic circuit by way of one of said reversers whereby the hydraulic actuating, medium is rendered available ior actuation of said second support shitting motor, an additional serially arranged reversing mechanism in said circuit for determining the direction of actuation of said second support motor, and additional means for i'endering said available hydraulic medium ineflective as respects said second support shifting motor.

21. A machine tool having relatively movable work and tool supports including means for shirtin: one of said supports and means for clamping said support against shifting movement, a first hydraulic motor for effecting shifting of thesupport, an additional hydraulic motor mechanism for controlling the clamp, and a hydraulic control and actuation system for said parts including a' source of hydraulic fluid, a first reverser for coupling the hydraulic medium to actuate the support in reverse directions, a second reverser coupling the hydraulic fluid for movement of the clamp into engaging or releasing position, a single actuator controlling the movement of both reversers, an interlock between said reversers whereby coupling of hydraulic medium for actuation of the support is prevented when the clamp is engaged, a delay mechanism for determining the sequential operation of the reversers by their common actuator, a second shiftable support, a hydraulic motor for actuation thereof, means for conditioning the hydraulic circuit by way of one of said reversers whereby the hydraulic actuating medium is rendered available for actuation ,of said second support shifting motor, an additional serially arranged reversing mechanism in said circuit ior'detennining the direction of actuation of said second support motor, said mechanism including a primary and a secondary reversing valve, and additional delayed action combined decelerating and reversing valve actuable by the secondary reverser, and delay means for determining the responsiveness of the lastmentioned valve to the reverser in coupling the controlled hydraulic actuating medium to said second support shifting motor.

22. A machine tool having relatively movable work and tool supports including means for shifting onev of said supports and means for clamping said support against shifting movement, a first hydraulic motor for efiecting shifting of the support, an additional hydraulic motor mechanism for controlling the clamp, and a hydraulic control and actuation system for said parts including a source of hydraulic fluid, a first reverser for coupling the hydraulic medium to actuate the support in reverse directions, a second reverser coupling the hydraulic fluid for movement of the clamp into engaging or-releasing position, a single actuator controlling the movement of both reversers, an interlock between said reversers whereby coupling of hydraiilic medium for actuation of the support is prevented when the clamp is engaged, a delay mechanism for determining the sequential operation of the reversers by their common actuator, a second shiftable support,-a hydraulic motor for actuation thereof, means for conditioning the hydraulic circuit by way of one of said reversers whereby the hydraulic actuating medium is rendered available for actuation of said second support shifting motor, an additional serially arranged reversing mechanism in said circuit for determining the direction of actuation of said second support motor, said mechanism including a primary and a secondary reversing valve, and additional delayed action combined decelerating and reversing valve actuable by the secondary reverser, delay means for determining the responsiveness of the last-mentloned valve to the reverser in coupling the controlled hydraulic actuating medium to said second support shifting motor, and means in serial relation with said last-mentioned reversing mecha-.

nism for determining the effectiveness of the hydraulic medium as respects said second sup-v port motor.

HANS ERNST.

ALBERT H, BALL. 1

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