US2352428A - External-internal cylindrical grinding machine - Google Patents

Description

June 27, 1944. J. I. GARSIDE V EXTERNAL-INTERNAL CYLINDRICAL GRINDING MACHINE Filed Nov. 9, 1943 3 Sheets-Sheet 1 3mm JOHN ,I. GARE/13E 93 3% RN mm June 27, 1944. J. I. GARSIDE' EXTERNAL-INTERNAL CYLINDRICAL GRINDING MACHINE Filed Nov. 9, 1943 3 Sheets-Sheet 2 Q mm Q NR. QN U mum QON QZDDI m k. mmmwimhm .JUHN I. GAR-SIDE June 27, 1944. J. I. GARSIDE EXTERNAL-INTERNAL CYLINDRICAL GRINDING MACHINE Filed Nov. 9, 1943 s Sheets-Sheet s \k\ mxqmnim U \QN E m M 5 mm R Q /V QQ N QQN PM NN mill! III. N Q UQNN \Q SN H I w H D RN MN R 9.3 mm mm k Patented June 27, 1944 UNITED STATES PATENT OFFICE EXTERNAL-IN TERN AL CYLINDRICAL GRINDING MACHINE John I. Garside, West Boylston, Mass, assignor to Norton Company, Worcester, Mass., a cor- .poration of .Massachusetts Application November 9', 1943, Serial No. 509,580

.(Cl. '51 s) 12 Claims.

The invention relates to grinding machines, and more particularly to a grinding machine for grinding both external and internal surfaces of a Work piece.

One object of the invention is to provide a simple and thoroughly practical hydraulically operated grinding machine for successively grinding external and internal cylindrical surfaces on a work piece. Another object of-the invention is to provide a hydraulically operated external-internal grinding machine with two independent. hand operated table traversing mechanisms, one for traversing the table when in an external. grinding position, and the other for operating the table when in an internal grinding position.

Another object of the. invention is to provide an interlock whereby the hydraulic feed is rendered inoperative when the internal hand traverse mechanism is operative. Another object of the invention is. to provide an interlock whereby the external hand traverse mechanism is rendered inoperative when the internal hand traverse mechanism is operative.

Another object of the invention is to provide an interlock which prevents initiation of a forward feeding movement of the external grinding wheel and wheel slide when the table is in an internal grinding positions Another. object of the invention is to provide an interlock whereby the internal hand traverse mechanism is rendered inoperative when the work table is in an external grinding position.

A further object of the invention is to provide an electrically controlled interlock whereby the solenoid for actuating the wheel feed control valve is rendered inoperative when the work table is moved toward an internal grinding position. A further object or this invention is to provide a hydraulically operated interlock between the external hand traverse mechanism and the internal hand traverse mechanism whereby only one of said mechanisms is in an operative position.

A further object of the invention is to provide a hydraulic interlock mechanism between the external hand traverse mechanism and the internal hand traverse mechanism whereby the internal traversc'mechanism is rendered inoperative when the table is in an external grinding position, and

to render the external hand traverse mechanism inoperative and the internal hand traverse mechanism operative when the table is moved into an internal grinding position. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, as will be exemplified in the structure to be hereinafter described, and the scope of the application of which will be indicated inthe following claims. 7

- In the accompanying drawings in which is shown one of various possible embodiments of the mechanical features of this invention,

Fig. 1 is a front elevation of the improved external-internal cylindrical grinding machine;

Fig. 2 is a plan view of the grinding'machine, as shown in Fig. l;

Fig. 3 is an electrical wiring and hydraulic piping diagram illustrating the hydraulic actuating and the electrical controlling mechanisms of the grinding machine;

Fig. 4 is a fragmentary cross-sectional view, on an enlarged scale,takenapproximately on the line 4-4 of Fig; 1, showing the external hand traverse mechanism; and

'Fig. 5 is a fragmentary longitudinal sectional view, on an enlarged scale, taken approximately on the line 55 of Fig. 2, showing a portion of the headstock in cross section.

A combined external-internal grinding. machine has been illustrated in the drawings, in which a base IE) serves as a support for a longitu dinally'reciprocable work supporting table II, as shown in Fig. 4 The table I I is arranged to slide longitudinally on a V-way I2 and flat way I3 formed on the upper surface of the base I0. The work table I I serves as a support for a head stock I5 which rotatably supports a work piece l6 mounted on a face plate for an external and internal grinding operation (Fig. 5).

A rotatable grinding wheel I! is supported on a wheel spindle (not shown) which is in turn journalled in suitabl bearings within a transversely movable wheel slide I8. The wheel slide the grinding wheel driving motor 2 I.

' The headstock I5 is provided with a rotatable headstock spindle 26 which is journalled in suitable bearings within the headstock I5 (Fig. 5). A variable speed D. C. motor 27 is mounted on the upper surface of the headstock I5 on a platen 28 rheostat 33 is also provided on the front of the machine base III which is operatively connected in the control circuit for the motor 21 to facilitate regulation of the speed of rotation of the headstock spindle 26.

A transversely movable internal grinding wheel slide 35 is mounted for a transverse adjustment relative to the base It] on a V-way 36 and a fiat way 31. The slide 35 serves as a support for a rotatable wheel spindle 38 which supports an internal grinding wheel 39. An electric motor 49 is adjustably mounted on the upper surface of the internal grinding wheel slide 35. The motor 49 is provided with a driving pulley 4| which is connected by a driving belt 42 with a pulley 43 mounted adjacent to the right-hand end of the internal grindingwheel spindle 38. A push button switch 44 is provided on the front of the machine base It to facilitate starting or stopping the internal grinding wheel driving mo tor 40.

The external grinding wheel slide I8 is arranged to be adjusted transversely relative to the machine base I 9 by means of a rotatable cross feed screw 45 which is engaged by a half nut 46 depending from the wheel slide l8 '(Fig. 3). A manually operable feed wheel 41 is provided on the front of the machine base I!) to facilitate a manual transverse adjustment of the wheel slidel8 toward or from the work piece It to be externally ground.

A manually operable feed wheel 48 is rotatably supported in a horizontally extending casing 49 which is connected by bevel. gears (not shown) with a vertical shaft contained within the vertical housing 50 which is supported on the upper surface of the internal grinding wheel slide 35. The manually operable feed wheel 48 is operatively'connected in the conventional manner to r move the internal grinding wheel slide 35 transversely relative to the base It! to adjust the position of the internal grinding wheel 39 relative to the work piece 66 for internal grinding.

Manual I table traverse The table II is arranged to be traversed longitudinally relative to the base It) by means of a manually operable traverse mechanism comprising a manually operable hand wheel 55 which is rotatably supported on a fixed shaft 56 (Fig. 4). A small gear 51 is connected to rotate with the hand wheel 55 and meshes with a gear 58 which is keyed to a shaft 59 which is in turn rotatably journalled in ball bearings mounted in an apron 62 which is fixedly mounted on the front of the machine base I9. A gear 63 is rotatably mounted adjacent to the right-hand end of the shaft 59. The gear 63 meshes with a rack plate 64 depending from the under side of the table H. The gear 63 is provided with clutch teeth on its left-hand side face (Fig. 4) which are arranged to be engaged by a slidably mounted clutch member 65 which is slidably keyed to the shaft 59. A compression spring 66 normally maintains the clutch member 65 in engagement with the clutch teeth on the gear 63. To facilitate disengagement of the clutch member 65, a bell crank lever 61 is pivotally supported on a rock shaft 68. The vertical arms of the bell crank lever 67 are provided with studs which engage shoes sliding in a groove in the clutch member 65. An integral horizontally extending arm of the bell crank lever 61 is arranged to be engaged by the head of a screw 69 which is adjustably mounted on the upper end of a piston rod 70. The lower end of the piston rod is formed as a piston H which is slidably mounted brackets 95 and 96,

within a cylinder F2 integral with the apron 62. A compression spring '13 normally tends to hold the piston ll in a downward position (Fig. 4). When it is desired to disengage the clutch 65, fluid under pressure is admitted in a manner to be hereinafter described through a pipe 14 into a cylinder chamber I5 formed in the lower portion of the cylinder 1'2. The manually operable traverse mechanism just described serves to .facilitate a manual adjustment of the table II when it is in an external grinding position,

such as that shown in Figs. 1 and 2.

Auxiliary manual table traverse When the work table. II is moved toward the right into an internal grinding position, it is desirable to pr'ovide an auxiliary table traversing mechanism adjacent to the controls for the internal grinding wheel 39. An auxiliary manually operable feeding mechanism is provided comprising a manually operable hand wheel (Figs. 1 and 2'). The auxiliary manually operable table traversing mechanism is identical with the manual traverse mechanism just described and illustrated in Fig. 4; consequently this aux-" iliary mechanism has not been illustrated in.

detail. A fluid pressure mechanism is provided for disengaging the clutch in the auxiliary table traversing mechanism comprising a cylinder Bl which is integrally contained within an apron 82 which is fixedly mounted on the front of the machine base H). A slidably mounted piston 83 is contained within the cylnder 8|. A compression spring 88 normally tends to hold the piston 83 in a downward position to engage the clutch teeth. The piston 83 is provided with an upwardly extending piston rod 84 which is provided with an adjustably mounted screw 85 which engages a bell crank lever (not shown) for actuat ing the clutch to disengage the auxiliary traversing mechanism contained within the apron 82. When it is desired to render inoperative the auxiliary traversing mechanism, fluid under pressure is admitted through a pipe 86 in a manner to be hereinafter described into a cylinder chamber 81 to cause an upward movement of the piston 83 which serves to disengage the clutch (not shown) which is identical with that shown in Fig. 4, to render the auxiliary manually operable traverse wheel 89 inoperative.

Work table control The table II is preferably reciprocated by a hydraulically operated mechanism comprising a cylinder 99 which is supported in fixed relation with the under side of the table II. A pair of spaced pistons 9| and 92 are slidably mounted within the cylinder and are connected by hollow piston rods 93 and 94, respectively. The hollow piston rods 93 and 94 are connected to hollow respectively, which are mounted in fixed relationwith the opposite ends of the base I0.

Fluid under pressure is supplied from a suitable source, such'as a reservoir 91 .formed in a box-like portion of the base I0. 'A motor. driven fluid pump 98 is controlled by a push "button switch 99 on the front of the machine base 18. The pump 88 draws fluid through a pipe I from the reservoir 91 and forces fluidunder pressure through a pipe 'IOI to a table reversing valve I02. An adjustable relief valve I03 is'connected in the pipe line IOI to allow excess fluid under-pressure to exhaust directly .intothe reservoir 91.

The control valve I02 is preferably a two-part valve, one part of which slides relative to the other. A slidably mounted valve stem I04 is provided with a pair of spaced valve pistons I05 and I06. A reduced cylindrical portion IIl'I of the valve stem I04 passes through a central aperture formed in a slidably mounted reversing valve member I08. The reversing valve member I08 is provided with a; plurality of spaced, integrally formed valve pistons I09, H0 and III. In the position of the valve parts as shown in Fig. 3, fluid under pressure passing through the pipe IOI enters a passage H2 in thevalve'casin'g and passes through the ports H3 into a valve chamber H4 and outwardly through a pipe H5, a pipe H6, through the hollow bracket 98, through the hollow piston rod 94 and the'hollors piston 92, into 'a cylinder chamber III "formed at the right-hand end of the cylinder 90 to cause a movement of the table II toward the right.

During this movement fluid within a. cylinder chamber H8 formed at the left-hand end of the cylinder 90 exhausts outwardly through the ho]- low piston rod 93, through the hollow bracket 95, through a pipe H9 and a passage I, into a V valve chamber I2I' formed between'the valve pistons I89 and H0. Fluid exhausting into the valve chamber I2I passes outwardlythrough an exhaust pipe I22 which in the normal table operating position passes fluid through an exhaust pipe I23 into the reservoir 91'.

A reversing lever I24 is mounted on the forward end of a rock shaft. I25. The rock shaft I25 supports a downwardly extending lever I26 the lower end of which is operatively connected to thefvalve stem I 04.. The reversing lever I24 may be shifted either manuallyor by table actuated dogs (not shown) to change the direction of movement of the table] I.

A combined start and stop and speed control valve I2'I is provided which is preferably formed integral with the control valve I02, but for the sake of simplicity of illustration, it has been illustrated diagrammatically in Fig. 3 as a separate valve. The valve 12! is preferably located in the exhaust side of the system so as to maintain a'uniform pressure on the operating side of the main cylinder 90 during the entire reciproca tory stroke of the cylinder 90 relative .to the pis-' tons 9| and 92. The valve I21 comprises a valve stem I28 having formed integrally therewith a plurality of valvepistons I29, l30 and I3I. The

control valve I21 is arranged so that it may be shifted longitudinally and also rotarily adjusted by means of acontrol knob I32. The right-hand end face of the valve piston I31 is formed as an angular plane face I33. By rotarily adjusting the valve stem I 28, the positionof the angular plane end face'I33 may be adjusted to open or close 'a V-port I34 'tothe desired and predetermined extent when the valve stem is'in a table operating position, that is, moved toward the left (Fig. 3). This rotary adjustment'of the valve stem- I28 serves as a fine adjustment to'cut off more or less of the V-port I34, thereby-controlling the exhausting fluid from the table cylinder precisely to regulate the reciprocatory movement of the table II.

In order that the valve piston I3l maybe maintained in the desired adjusted position dur= ing the starting and stopping of the table II, a serrated portion I35 is formed integral with the valve stem I28. An arrow-pointed spring pressed plunger I36 is supported by the casing of' the valve I27 and is maintained in engage mentwi'th .theserrated portion I35 so that the valve stem I28 may be moved endwise to start and stop the table movement without changing the speed adjustment thereof.

A manually operable stop and start lever I31 is pivotally mounted on a stud I38. The stud I38 is supported by a boss I39 which is formed as an integral projection of an apron I40 which is in turn fixedly mounted to the front of the machine base l0. The control lever I3! is provided with a clearance aperture I4I Which surrounds a sleeve I42. The sleeve I42 is supported o'nithe valve stem I28 and is provided with a pair of diagrammatically opposed parallel grooves I43 which areengaged by a pair of diagrammatically opposed studs I44 carried by the control lever I31. It will be readily apparent from the force going disclosure that when the control lever I31 is positioned as indicated in Fig. 3, the V-port I34 is closed, thus preventing exhaust of fluid from the table cylinder 90 and maintaining the table II in a stopped position.

When it is desired to start the reciprocating movement of the-table I I, the control lever I337 is shifted in a counter-clockwise direction (Fig.

3) which movement shifts the valve stem I28 from the cylinder chamber 15 and a valve cham-' ber I4I connects the pipe I4 with a pipe I48 which is connected to the fluid pressure pipe I0 I, thereby admitting fluid under pressure through the pipe I4 into the cylinder chamber 15 in the cylinder I2. This raises thepiston II so that the screw 69 in the valve stem I0 engages the lower arm of the forked bell crank lever 61 to disengage the teeth on the clutch member 65 from the clutch teeth on the gear 63. This makes the manually operable traverse mechanism operated by the hand wheel 55 neutral or inoperative during the hydraulic actuation of the table II. When the table II is stopped by shifting the valve stem I28 toward the right (Fig. 3), the released tension of the springs'13 and 66 will move the piston II downwardly, exhausting fluid in the cylinder chamber I5 through the pipe I4. The released tension of the spring 66 will move the clutch member 65 to engage the clutch teeth on the gear 65 so that the hand wheel 55 may be used to traverse the table II manually.

'When the throttle valve I2! is in a. closed position (Fig. 3). it is desirable to provide a suitable by-pass whereby fluid ma-y readily pass from the'cylinder chamber I 1 into the cylinder chamber H8 and vice versa to facilitate a manual traversing movement of the table II.

v A pipe I45- is-connected between the valve I02 and the valve I21. Similarly, a pipe I46 is connected between the valve I02 and'the valve I21. In the position of the valve I21, the pipes I45 and I46 are con nected by the valve chamber I41 formed between the valve pistons I38 and I3I. It will be readily apparent from the foregoing disclosure that fluid may readily pass from the cylinder chamber II1 through the pipe II6, the pipe I46, through the valve chamber I41, through the pipe I45 and the pipe H9, into the cylinder chamber IIILso that the table II may be readily traversed longitudinally by a manually operable traversing mechanism to be hereinafter described without meeting any resistance from the fluid within the system.

Wheel feeding mechanism l The cross feed screw 45 previously described is slidably keyed within a hollow portion of a rotatable shaft I50. The shaft I 50 is journalled at one end in a bearing II in a wheel slide base I52 which serves as a support for the forward end of the feed screw'45. The rear end of the feed screw 45 is journalled in a bearing contained within a slidably mounted sleeve i53 which is slidably supported within a cylindrical aperture in the wheel slide base I52 which is fastened to the base I8. It will be readily apparent from the foregoing disclosure that a rotary motion of the manually operated feed wheel 41 may be imparted to rotate the feed screw 45 to transmit a feeding movement through the half nut 45 to the wheel slide It and the'grinding wheel I1.

' In order to facilitate a'rapid'movement of the external grinding wheel slide I8 to and from an operative position, a hydraulically operated mechanism is provided for moving the feed screw 45 in an axial direction. This mechanism may comprise ahydraulic cylinder I54 which is arranged in axial alignment with the feed screw 45. A slidably mounted piston I55 is contained within the cylinder I54. A double end piston rod I56 is fixedly connected to the piston I55 and is connected at its left-hand end (Fig. 3) to the slidably mounted sleeve I53. It will be read ily apparent from the foregoing disclosure that when fluid under pressure is admitted to 9. cylinder chamber I51 to cause the piston I55 to move toward the left, it will impart a forward approaching or feeding movement through the feed screw 45 to move the external grinding wheel slide III'and grinding wheel I1. Similarly, as fluid under pressure is admitted to a cylinder chamber I58 to cause the piston I55 to move toward the right into the position illustrated in Fig. 3, a rearward movement of the grinding whee1'I1 may be obtained.

A reversing or feed control valve I60 is provided for controlling the-admission to and exhaust of fluid fronrthe feed cylinder I54. The valve I66 is a piston type valve comprising a valve stem IEI having formed integrally therewith valve pistons I62, I63, I64 and I65. A compression spring I56 normally serves to hold the valve stem IGI inits right-hand end position (Fig. 3). An electric push type solenoid I01 is operatively connected to the valve stem I6I so that when energized, the solenoid I61 will move the valve stem- I6I toward the left against the compression of the spring I66 to reverse the flow of fluid under pressure to the cylinder I54.

Fluid under pressure from the pump 98 passing through the pipe IOI passes through a-pipe I68, into a valve chamber located between the valve pistons I63 and I54,and through a pas-v sage I69 into the cylinder chamber I58 to move the piston I55 rearwardly, that is, toward the right (Fig. 3) into the position illustrated. During this movement, fluid within the cylinder chamber I51 exhausts through a passage I10, into a valve chamber located between the valve pistons I62 and I63, and passes outwardly through an exhaust pipe I1I into the reservoir 91. A throttle valve I12 is provided in the exhaust pipe line I1I whereby the rate of exhaust of fluid from the feed cylinder I54 may be regulated as desired so as to control the transverse feeding movement ofthe grinding wheel I1. The mechanism above described produces a comparatively rapid or reduced forward feeding movement of the grinding wheel I1.

Dash pot feeding mechanism A suitable fluid pressure control or feed regulating mechanism is provided for modifying the rapid approaching movement caused by the piston I55 to obtain a controlled and predetermined grinding feed of the grinding wheel I1. A selfcontained dash pot feed regulator is provided comprising a pair of dash pot cylinders I15 and I16 which contain slidably mounted dash pot pistons I11 and I18. The dash pot pistons and cylinders are arranged with their axes parallel to each other and are spaced on diagrammatically opposite sides of the axis of the piston rod I56. The dash pot pistons I11 and I18 are normally held in a rearward or right-hand position by means of the compression springs. An adjustable stop screw I19 serves to limit the rearward movement of the dash pot pistons I11 and I18. A slidably mounted sleeve I surrounds and is supported on the rearwardly extending portion of the piston rod I56. The sleeve I80 is provided with a flanged portion I8I which is either formed integral with or fixedly secured to the sleeve I80. The flange I8I is arranged to engage the right-hand end face of the dash pot pistons I11 and I18, respectively. The stop screw I19 engages the flange I8I and thereby serves to limit the rearward movement of the dash pot pistons I11 and I18.

The rapid approaching or forward feeding movement of the grinding wheel I1 and the wheel slide I8 continues until an adjustable nut I82 on a threaded portion I83 of the rearwardly extending portion of the piston rod I56 engages the right-hand end of the sleeve I80. Continued movement of the piston rod I56 moves the sleeve I80 and the flange IBI toward the left to move both of the pistons I11 and I18 also toward the left. When the flange 'I8I engages the ends of the dash pot pistons I11 and I18 respectively, the rapid approaching feeding movement of the grinding wheel I1 toward the work piece I6 is reduced to a slower, predetermined grinding feed due to the fact that fluid compressed within the dash pot cylinders I15 and I16 respectively which are interconnected exhausts through a passage I84, a needle valve I85, through a pipe I86, into a reservoir I81. By adjusting the aperture of the needle valve 35,. a desired and predetermined infeeding movement of the grinding wheel I1 may be obtained.-

When fluid is admitted to the cylinder chamber I58 to cause a rearward movement of the piston I55, the sleeve I88 together with the flange IBI is moved rearwardly by means of the released compression of the springs within the dash pot cylinders I15 and I16 which returns the dash pot pistons I11 and I18 respectively to their rearward position and moves the flange I80 into engagement with the stop screw I19. The rearward movement of the dash pot pistons I11 and I18 serves to draw fluid from the reservoir I 81, through a pipe I88'and a ball check valve I89, to fill the dash pot cylinders I15 and I16 for the necessary infeeding movement of the grinding wheel I 1. During the infeeding movement of the dash pot pistons I11 and I18, fluid within the dash pot cylinders I15 and I16 servesto hold the ball check valve I89 closed so that fluidwithin the dash pot cylinders I15 and I16 is forced out through the needle valve I85.

A throttle needle valve I90 is connected by the pipe I88 to a chamber I9I to facilitate exhaust of fluid from the dash pot cylinders'l15 and I18 as the passage I84 is closed by the dash pot piston I 11. If desired, the throttle valve I90 may be used to produce a very fine, final feeding movement of the grinding wheel I1 just prior to the engagement of a stop surface I93 by an adjustable positive stop I92 which positively limits the forward feeding movement of the grinding wheel I1 toward the work piece I6. In the latter case, two distinct feeds of the grinding wheel I1 may be obtained; manipulation of the needle valve I85 combined with the opening of the needle valve I90 iscontinued until the passage I84 is cut off, after which the needle valve I90 controlsthe rate of advance of the grinding wheel I1.

Electrical control An electrical control circuit is provided for stopping and starting the grinding cycle, comprising a pivotally mounted control lever 200 which is pivotally-supported on a bracket in a fixed relationship with the front of the machine base Ill. The control lever 200 is arranged when moved in a counterclockwise direction (Fig. 3) to actuate a push button starter switch 20I or when rocked in a clockwise direction to. actuate a push button stop'swit'ch'202 whereby-the grinding cycle may be started or interrupted when desired. Each push button switch 20I and 202 is connected through a magnetic starter or relay switch 203 to control the energizing and deenergizing of the push type solenoid I61 so as to actuate the feed control valve I60-as desired. A normally closed limit switch .204 is mounted on the headstock I5 and is arranged to be actuated by a cam plate 205 which is fixedly mounted relative to the base I0 (Fig. 4) When the table II is traversed toward the right into an internal grinding position, an actuating roller 206 of the limit switch 204 rides onto the cam plate 205 which opens the contacts of thelimit switch 204 and thus opens a circuit to deenergize or to prevent energization of the solenoid I61 so as to prevent an infeeding movement of the external grinding wheel I1 and the wheel slide I8 while the table II is in an internal grinding position. This prevents the grinding wheel I1 from being fed accidentally into the rear side of the headstock I5. I v

A control valve 208 is provided for controlling the passage of fluid under pressure to the cylinders 12 and 8|, respectively, to render the manually operable traverse wheels 55 and 80 together with their respective mechanisms inoperative in a a manner to be hereinafter described. The. control valve 208 is a piston type valve comprising a valve stem 209 having formed integrally therewith valve pistons 2I0, 2II, 2|-2 when energized it will shift the valve stem 209 toward the left (Fig. 3) to change the direction of flow of fluid under pressure. In the position illustrated in Fig. 3, fluid under pressure from the pump 98 passing through the pipe IOI passes through a pipe 2I6 into a valve chamber located between the valve pistons 2H and 2I2and passes outwardly through the pipe 86 into the cylinder chamber 81 of the cylinder BI to move the valve p ston 83 upwardly, and thus to disconnect the clutch on the auxiliary table traverse mechanism so as to render the hand traverse wheel inoperative.

In the above position of the valve 203, fluid within the cylinder chamber 15 formed in the cylinder 12 may exhaust through the pipe 14, through a valve chamber 2 I 1 formed between the valve pistons l29 and I30 in the control valve I21, and pass outwardly through a pipe 2I9 into a valve chamber located between the valve pistons H0 and 2H of the valve 208. Fluid exhausting through the valve chamber located between thevalve pistons 2I0 and 2H exhausts through a pipe 220 into the reservoir 91.

When the solenoid 2I5 is energized toshift the valve stem 209 into a left-hand end position, fluid under pressure passing from the pipe 2I6 into a valve chamber located between the valve pistons 2H and 2I2 may pass outwardly through the pipe 2I9, through the valve chamber 2I1 in the control, valve I21, intothe cylinder chamber 15 to move the piston 1I upwardly so as to move the clutch member 65 out of engagement with the clutch teeth formed on the gear 63, thus rendering. inoperative the manually operable table traverse mechanism contained in the apron 62 which traverses the table II during an external grinding operation.

A push type solenoid 225 is operatively connected by a link228 with a stud 221 which is supported at the lower end of the control lever I31. Assuming the control lever I31 is ,to be rocked in a counterclockwise direction from the position illustrated in Fig. 3 during the hydraulic traversing movement of the table II, when the solenoid 225 is energized the link 226 will be moved toward the left to rock the control lever I31 in'a clockwise direction to close the'V-port I34 and thus stop the hydraulic movement of the table I I.

,It is desirable automatically to control the energization of the solenoids 2I5 and 225 in timed relation with the movement of the table I I .to an internal grinding position. A snap action, single pole, double-throw switch 228 is mounted on the base ID of the machine. An-actuating lever 229 of the switch 228 is arranged in the path of a longitudinally adjustable table dog 230 which is supported by the T-slot 23I formed in the front edge of the table II. The dog 230 is arranged so that when the table II is moved toward the right into an internal grinding position, the dog 230 engages the actuating lever 229 of the switch 228 and rocks it from the dotted line position (Fig. 3) to the dot-dash position 229a and snaps the electrical contact prongs in a closed position which serves to energize the solenoids .2I5 and 225 The energization of the solenoid 215 serves to. shift the valve stem 209 toward the left so that fluid contained within the cylinder chamber 81 may exhaust through the pipe 86 into a valve chamber located between the valve pistons 2I2 and 2I3 and pass outwardly through the exhaust pipe 220 into the reservoir 91, thus allowing the piston 83 to move downwardly under the released compression of the spring 88 which surrounds the piston rod 84. This movement of the piston 83 serves to render operative the auxiliary manually operable table traverse mechanism as controlled by the hand wheel 80 so that the table I I may be traversed longitudinally during the internal grinding operation from a point adjacent to the operator's station during this operation.

At the same time as the solenoid 2I5 is energized, the solenoid 225 is also energized to shift the control lever I3I into the position illustrated in Fig. 3, thus closing the V-port I34 to stop the hydraulic traverse of the table I I and at the same time allowing fluid under pressure from the valve 208 to pass through the pipe 2I9 through the valve chamber 2I'I and in the valve I2'I, into the cylinder chamber I5, to cause an upward movement of the piston II, thus shifting the clutch member 65 toward the left (Fig. 4) into a disengaged position, thus rendering the normal table traversing mechanism as governed by the manually operable hand wheel 55 inoperative during the internal grinding operation.

After the internal grinding operation, the table II is again shifted toward the left into position for an external grinding operation. The initial movement of the table II toward the left is manually controlled until the lever 229 is rocked by the dog 230 and snaps the switch 228 to the open position. Then the table I I may be shifted hydraulically to the desired loading position.

Operation The operation of the improved external and internal cylindrical grinding machine will be readily apparent from the foregoing disclosure. A work piece It to be ground is mounted on the face plate on the headstock spindle 26, after which the work table I I is moved longitudinally to position the external grinding wheel IT in operative relation with the external portion of the work piece I6 to be ground. The control lever I31 is shifted to open the V-port I34 to cause the desired longitudinal movement of the work table II.

By manipulation of the lever I24, the direction of movement of the table I I may be readily controlled. When the work table I I has been moved to the predetermined external grinding position, the control lever 200 may be shifted in a counterclockwise direction (Fig. 3) to energize the solenoid H51 in a manner above described to shift the valve stem I6I so as to admit fluid under pressure to the cylinder chamber I51 to initiate a forward feeding movement of the external grinding wheel I1 and its supporting wheel slide I8. The forward feeding movement of the grinding wheel I! is continued until the contact collar of the positive stop I92 engages the positive stop surface I93 after which the control lever 200 may be rocked in a clockwise direction to actuate the push button switch 202 to break the circuit, thus deenergizing the solenoid I61 which allows the released compression of the spring I66 to return the valve stem I6I into the position illustrated in Fig, 3 so that fluid under pressure is admitted to the cylinder chamber I58 to cause a rearward movement of the external grinding wheel I! to an inoperative position,

When it is desired to move the table II into an internal grinding position, the control lever I3! is moved in a counterclockwise direction (Fig. 3) to shift the valve stem I28 toward the left to open the V-port I34 so as to allow fluid to exhaust from the table cylinder 90, thus starting a hydraulic traversing movement of the table II. Thetable II moves toward the right into an internal grinding position until the table dog 230 engages and actuates the snap switch 228 to close a circuit, thus energizing the solenoids 2I5 and 225 to shift the valve stem 209 toward the left (Fig. 3) and to move the start and stop valve I21 into the position illustrated in Fig. 3. This movement allows the piston 83 to move downwardly so as to render operative the auxiliary manual traverse mechanism as governed by the hand Wheel so that the table II may be traversed manually during an internal grinding operation. During the internal grinding operation, the internal grinding wheel 39 together with its supporting slide 35 may be moved transversely by means of the manually operable feed wheel 48.

When the table. II is moved toward the right into the internal grinding position, the cam plate 205 which is fixed relative to the base I0 engages the roller 206 to actuate and open the limit switch 204 so as to open the circuit and prevent energization of the solenoid I61, thus preventing an infeeding movement of the exfeeding movement of the external grinding wheel I! inoperative when the table I I is in an internal grinding position. An interlock is provided also to render the auxiliary table traverse wheel 80 inoperative when the table II is in an external grinding position. An interlock is also provided to render the auxiliary traverse wheel 80 operative and the manually operable traverse wheel 55 inoperative while the work table II is in an internal grinding position.

The manually operable hand traverse mechanisms for traversing the work table II when inan external and an internal grinding position, respectively, are preferably two-speed hand traverse mechanisms, such as that disclosed in the expired U. S. patent to C. H. Norton, et al. No. 1,299,765 dated April 8, 1919, to which reference may be had for details of disclosure not contained herein. Control knobs 235 and 236 are provided on the hand wheels 55 and 80, respectively, for shifting the speeds of the traverse mechanisms.

In grinding relatively short work pieces, the headstock I5 is positioned as indicated in Figs. 1 and 2 for an external operation, after which the headstock I5 is shifted longitudinally on the table II into engagement with a stop 234 for an internal grinding operation. While the headstock is thus positioned, the table II is moved toward the right into an internal grinding position.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As various possible embodiments might be made of the mechanical features of the above invention and as the art herein described might be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinbefore set forth or shown in the accompanying gages drawings is to be interpreted as illustrative and not in alimiting sense.

I claim:

1. In a grinding machine having a base, a longitudinally movable Work table thereon, a rotatable work support on said table, a rotatable grinding wheel, a transversely movable slide therefor, a second rotatable grinding wheel, a transversely movable slide therefor which is spaced from said first slide, means to'move said first grinding Wheel slide transversely, means including a solenoid operatively connected to initiate an 'infeeding' movement of the first grinding wheel,means to traverse said table to a second grinding position;

and an interlock including an electric switch which is automatically actuated by movementof the table to control an electric circuit and prevent actuation of the solenoid to initiate an in,- feeding movement of the first grinding wheel while the table is in a second grinding position.

2. In a grinding machine having a base, a longitudinally movable work table thereon, a rotat able Work support on said table, an external rotatable grinding wheel, a transversely movable slide therefor, an internal rotatable grinding wheel, ,a transversely movable slide therefor which is spaced from said first slide, means to move said external grinding Wheel slide ransversely, means including a solenoid operatively connected to initiate an infeeding movement of the external grinding wheel, manually operable means to traverse said table to an internal grinding position, and an interlock including an electric switch which is automatically actuated by movement Of the table to control an electric circuit and prevent actuation of the solenoid to initiate an infeeding movement of the external grinding wheel while the table is in an internal grinding position.

3. In a grinding machine having a base, a longitudinally movable work table thereon, a rotatable work support on said table, an external ro tatable grinding wheel, a transversely movable slide therefor, an internal rotatable grinding wheel, a transversely movable slide therefor which is spaced from said first slide, a hydraulic piston and cylinder to move said external grinding wheel slide transversely, a control valve therefor, means normally to maintain said valve in a position to move and maintain said slide in a rearward or inoperative position, a solenoidoperatively connected to shift said valve to initiate an infeeding movement of the external grinding wheel, manually operable means to traverse said table to an internal grinding position, and an interlock including a normally closed switch which is automatically opened by movement of the table to break a circuit and prevent energization of the solenoid while the table is in an internal grinding position. I

4. In a grinding machine having a longitudinally movable work table, a transversely movable rotatable grinding wheel, a manually operable traverse mechanism for traversing said table when in a first grinding position, means including a clutch to render said mechanism operative or inoperative, a secondmanually operable traverse mechanism which is spaced from the first for traversing said table when in a second grinding position, means including a clutch to render said second traverse mechanism operative or inoperative, and means including an interlock whereby one of said clutches may be engaged while the other is held disengaged.

5. In a grinding machine having a longitudinally movable work tablej a transversely mov able rotatable grinding .wheel, a manually operable'traverse mechanism for traversing said table when in a first grindingposition, mean s including a clutch to render said mechanism operative or inoperative, means including a fluid pressure piston and cylinder to disengage said clutch, a second manually operable traverse mechanism which is spaced from the first for traversing said table when ina second grindingposition, means including a clutch to render said second mecha nism operative or inoperative, a fluid pressure piston and cylinder to disengage said clutch, and a control valve to' controlthe admission, of fluid under pressure to one or the'other of said cy inders; i g I 6. In a grinding machine having a glongitudinally movable work table, a transversely movable rotatable grinding wheel, a second transversely movable rotatable grinding wheel spaced from jsaid first wheel, a'manually operable traverse mechanism for traversing said tabl'ejwhen in an operative position with relation to the first wheel, means including a clutch t render said 'mecha' nism operative or inoperative, m'eansii'icluding a fluid pressure piston and cylinder to engage said clutch; a secondmanually operabl traverse mechanism which is spaced from the first for traversing said'table when in an operative position relative to said second grinding wheel, means including a clutch to render said second mechanism operative or inoperative, a fluid pressure piston and cylinder to disengage said clutch, and a control valve to control the admission of fluid under pressure to either one or the other of said cylinders.

'7. In a grinding machine having a longitudinally movable work table, a transversely movable rotatable external grinding wheel, a transverse- 1y movable rotatable internal grinding wheel spaced from said first wheel, a manually operable traversing mechanism for traversing said table when in an external grinding position, means including a clutch to render said mechanism operative or inoperative, means including a. fluid pressure piston and cylinder to disengage said clutch, a manually operable traverse mechanism for traversing said table when in an internal grinding position, a clutch which is normally engaged to control said mechanism, a fluid pressure piston and cylinder to disengage said clutch, and a control valve to control the admission of fluid under pressure to either one or the other of said cylinders.

8. In a grinding machine having a longitudinally reciprocable table, a piston and cylinder to reciprocate said, table, a reversing Valve, a control valve operatively connected therewith, a pair of spaced hand traverse mechanisms whereby the table may be manually traversed from two spaced operating stations, a clutch in each of said mechanisms, a spring normally to maintain said clutches in engagement, a separate hydraulic piston and cylinder to disengage each of said clutches, and a solenoid actuated valve to admit fluid under pressure to one or the other of said clutch cylinders.

9. In a grinding machine having a longitudinally reciprocable table, a piston and cylinder to reciprocate said table, a reversing valve, a control valve operatively connected therewith, a pair of spaced hand traverse mechanisms, a normally engaged clutch in each of said mechanisms, a separate hydraulic piston and cylinder to disengage each of said clutches, a solenoid actuated valve to admit fluid under pressure to one or the other of said clutches, and fluid connections whereby both of said clutches are disengaged and both of the hand traverse mechanisms rendered inoperative during the hydraulic movement of said table.

10. In a grinding machine having a longitudinally reciprocable table, a piston and cylinder to reciprocate said table, a reversing valve, a control valve operatively connected therewith, a pair of spaced hand traverse mechanisms for manually traversing said table, one of said mechanisms serving to traverse the table when in an external grinding position and the other of said mechanisms serving to traverse said table when in an internal grinding position, a clutch in each of said mechanisms, a hydraulic piston and cylinder to disengage each of said clutches, and a solenoid actuated valve to admit fluid under pressure to one or the other of said cylinders, said solenoid valve normally being in a position to admit fluid under pressure to the clutch cylinder to render the internal manual traverse mechanism inoperative.

11. In a grinding machine having a longitudinally movable work table, a piston and cylinder to reciprocate said table, a reversing valve, 2. control valve operatively connected therewith, a pair of spaced hand traverse mechanisms for manually traversing said table from two spaced positions, separate hydraulic piston and cylinders to disengage each of said clutches, a solenoid actuated valve to admit fluid to one or the other of said clutch cylinders, and fluid connections between the control valve whereby fluid pressure is passed through a chamber in said control valve into the clutch cylinder to render the manually operable table traverse mechanism inoperative when the control valve is opened to start hydraulic traverse of the table.

12. In a grinding machine having a longitudinally reciprocable table, a piston and cylinder to reciprocate said table, a reversing valve, a control valve operatively connected therewith, a pair of spaced hand traverse mechanisms whereby the table may be manually traversed from two spaced stations, a clutch in each of said mechanisms, 2 separate hydraulic piston and cylinder to disengage each of said clutches, a solenoid actuated 20 valve to admit fluid under pressure to one or the other of said clutch cylinders, and an electric switch which is closed by movement of said table into an internal grinding position to actuate and shift said solenoid control valve so as to 5 admit fluid under pressure to render the manually operable traverse mechanism inoperative while the internal manually operable traverse mechanism is rendered operative.

JOHN I. GARSIDE.

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