US2132953A

US2132953A - Grinding machine table reciprocating mechanism

Info

Publication number: US2132953A
Application number: US118460A
Authority: US
Inventors: Herbert S Indge
Original assignee: Norton Co
Current assignee: Saint Gobain Abrasives Inc
Priority date: 1936-12-31
Filing date: 1936-12-31
Publication date: 1938-10-11
Anticipated expiration: 1955-10-11

Description

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Oct. l1, 1938.

H. S. INDGE GRINDING MACHINE TABLE RECIPROCATING MECHANISM Oct. l1, 1938.

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Patented Oct. 11, 1938 UNITED s'rArEs G RlNDli-YG MACHINE TABLE RECIPRGCA'II-` ENG MECHANISM herbert s. Inage, westboro, Mass., signor-.to Norton Company, Worcester, Mass., a corporation of Massachusetts applicati@ December 31,' 1936, semi No. 118,460 ,l

'I s' (C1. 517233) p This invention relates to machine tools, and more particularly to a table traverse mechanism.

One object of this invention is to provide a simple, thoroughly practical machine tool table traverse mechanism. Another object of this invention is to provide a manually controlled table traverse mechanism by which the table may be traversed easily Without undue exertion.- Another object of the invention'is to provide a manually controlled, hydraulically operated table traversing mechanism. Another object of the invention is to provide a manually controlled, hydraulically actuated table traversing mechanism in which the speed of movement of the control member, such as the rotation of a hand Wheel, serves to control the rate of traversing movement of the table. A further object of the invention is to providea combined manually operable rack and gear and hydraulic traverse mechanism which'is so arranged that rotation of the manually operable table traverse wheel `serves to actuate and` control the position of a hydraulic control valveto control the traversing` movement of the table. 'Other objects will be in part obvious or in part pointed out hereinafter.

'Ihe invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts,l as will be exemplined in the structure to be hereinafter described, and the scope of the application of which will be indicated in the following claims.

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

. Fig; 1 is a fragmentary piping diagram of the fluid pressure system for automatically reciprocating and manually traversing the table;

Fig. 2 is a fragmentary sectional view, on a reduced scale, taken approximately on the line 2-2 of Fig. 5;

Fig. 3 is a front elevation of a grinding machine embodying this invention;

Fig. 4 is a fragmentary vertical sectional view, on an enlarged scale, taken approximately on the line 4--4 of Fig..3, 'showing the stop and start valve; and j Fi'g.l 5 i's a fragmentary cross. sectionalview, on an enlarged scale, taken approximately on the line 5 5 of Fig. 3. l.;

A cylindrical grinding machine has been illus-y trated in the drawings having a base I which is provided with, a Wheel slideI-I slidable transversely on the usual V and flat ways (not shown) A rotatable grinding wheel I2 is mounted on a Wheel spindle I3 which is supported for rotation in ,bearings (not shown) on the wheel slide II. The grinding wheel lI2 may be rotated from any suitable source of power, either by means of a driving belt from an overhead countershaft,or it 4may be driven by an electric motor I4 mounted 5 0n the wheel slide II. The motor I4 is provided j with an armature shaft I whichsupports val pull'ey I6. The pulley I6 is connected by a driving belt I1 with a pulley I8 mounted on the outer end ofthe wheel spindle I3. y

A work piece is rotatably supported on a headstock center r`2I carried by a headstock 22.

The other end of the work piece 20 issupported by a-footstock center 23 carried by a footstock center 24. 'I'he headstock 22 and footstock are mounted on a longitudinally movable table 25 which slides on a nat way 26 and a V way 21 on the base I0. J

The grindingwheel slide II is arranged for a transverse feeding movement to cause the 20 grinding wheel I2 to approach or recede from the workpiece 20 so as to grind the same to the desired extent. A suitable feeding mecha- A nism is provided which may comprise the wellknown half nut\ and rotatable cross feed screw 25 (not shown) which are actuatedwby a manually operable feed wheel which is rotatably sup. ported 'on the front of the machine base. Thel feeding wheel 30 is provided with a micrometer adjusting mechanism 3l, and is arranged to be 30 rotatedautomatically by means of a reciprocable picker or ratchet pawl 32. The details of the grinding wheel feeding mechanism have not been illustrated in the present case'since they are not considered part of the present invention. The 35,

Wheel feedingmechanism utilized is a well-known, wheel feeding mechanism such as, for example, that shown, in the prior United` States patent to C. H. Norton, No. 762,838, dated June,..14, 1904.

For further details ofthe feedingmechanism, 40

reference may be had to the above-mentioned patent.

In a cylindrical grinding machine, it is desirable to provide a suitable power operated traversing orf-reciprocating mechanism to cause a relative longitudinal traversing movement between-'j the rotatable work piece and the rotatable grindl 1 ing wheel so as to grind the work piece to the required cylindrical form. In the preferred form,

'a fluid pressure operated mechanism is provided 50 Comprising ajuid pressure cylinder 40 which is preferablyA fixed to the base- III of the machine. A piston 4I is slidably mounted withinthe cylinder 40 and is provided with a double end piston rod 42 which extends through the opposite ends 55 of the cylinder 48 and is fastened to depending brackets 43, only one of which has been illustrated in the drawings. 'I'he brackets 43 depend from the opposite ends of the longitudinally movable work table 25 and are either formed integral therewith -or rigidly fixed thereto. A control or reverse valve 45 is provided to control the direc` tion of movement oi the -piston 4| and the table 25. The valve 45 is preferably a piston type valve comprising a valve stem 46 having valve pistons 41, 48 and 49 integrally formed therewith.

A fluid reservoir 50 is'located preferably within the base |8 of the machine. Fluid is pumped from the reservoir 58, through a pipe 5|, by means of a fluid pressure pump 52, and is forced through a pipe 53 and a pipe 54 and through ports 55 and 56, respectively, in the control valve 45. As shown in the position of the parts illustrated in Fig. 1, fluid under pressure passing through the pipe 54 and port 56 enters a valve' chamber 51 located between the valve pistons 48 and 49 and passes outwardly through a port 58 and a pipe 59 into a' cylinder chamber 68 to cause the piston 4| and table 25 to move in a direction toward the left (Fig. l). During the' movement of the piston 4| and table 25 toward the left, fluid is exhausted from a cylinder chamber 6| through a pipe 62, a port 63, into a valve chamber 64 located between the valve pistons 41 and 48, and passes out through an exhaust port 65 and a pipe 66, into the reservoir 58.

When it is' desired to reversethe direction of movement of the table 25, the valve stern 46 is moved toward the left (Fig. 1) so as to reverse the ow of iiuid pressure to and from the cyl- 'inder 48. In this position of the valve, fluid under pressure passing through the pipe 53, the DOrt 55, enters the valve chamber 64 between the valve pistons 41 and 48, and passes outwardly through the port 63, the pipe 62, into the cylinder chamber 6|, to move the piston 4| and table 25 toward the right, as viewed in Fig. 1. During this movement of the table, fluid within the cylinder chamber 68 is exhausted through the pipe 59, the port 58, into the valve chamber' 51, and out through the port 65 and the pipe 66, into the reservoir 58. The reverse or control valve 45 is preferably actuated automatically in timed relation with the movement of the work table 25. A reversing lever 18 is pivotally mounted on a stud 1| and its upper end is arranged in the path of

adjustable dogs

12 and 13 carried by the table 25. The reversing lever 18 is operatively connected to shift the reversing valve 45 in the desired timed relationship with the reciprocation of the table 25.

In order to control the speed or rate of movement of the reciprocable work table 25, a speed control or throttle valve 80 is provided. The speed control or throttle valve 80 is preferably arranged in the exhaust side of the fluid pressure system so that fluid under pressure exhausting from thel cylinder 48. is throttled'tovcontrol the speed of movement of the table. The throttle valve 88 is preferably of a piston type having a slidably mounted piston 8| within the valve casing 88. The valve piston 8| is provided with an angular planel end face 82 which is arranged to open or close a V-port 83 in the exhaust pipe 66 lso as to stop and start the flow of fluid in the table traversing mechanism or, when rotated in an open position, the angular plane end face 182 serves to vary the aperture of the V-port 83 so that the traversing speed of the table l25 may be readily varied, as desired. Fluid under pressure exhausting from the cylinder 48, through pipe 66, enters a chamber 84 in the valve 88 and exhausts therefrom, through a pipe 85, into the reservoir 0r sump 58.' In the full line position (Fig. 4), the valve piston 8| is in an operating position, with the V-port 83 uncovered.

A serrated portion 86 formed on a, valve stem 81 cooperates with a spring-pressed pawl 88 to maintain the valve piston 8| in the desired rotary position. Due to the fact that the grooves in the serrated portion 86 are arranged parallel to the axis of the valve, the valve piston 8| may b e moved from a stop to a starting position without changing the rotary position of the feed control surface 82 of the piston 8|. The valve stem 81 is journalled in a bearing block 98, anda manually operable control knob 9| is mounted on the outer end of `the valve stem 81 to facilitate a rotary adjustment of the valve to produce the desired speed.

In order to move the valve piston 8| from a stop to a start position, a manually operable control lever 92 is pivotally mounted on a stud 93 supported in a bracket 94 projecting from the front of the machine base .|8. The lever 92 is provided with diametrically opposed pins 95 which ride in slots 96 on opposite sides of the bearing member 98 (only one of the pins and slots being shown in dotted lines in Fig. 4 of the drawings) The pins 95 and slots 96 facilitate endwise movement of the valve piston 8| and also permit a rotary adjustment of the piston 8| to control the speed of movement of the table 25. To stop the exhaust of uid from the system so as to stop the movement of the table 25, the manually operable control lever 92 is moved into position 92a (Fig. 4) which shifts the control valve piston 8| so that its speed controlling end face 82 is in position 82a, thereby closing the vport 83 Vand preventing further exhaust of fluid from the system.

To attain the primary object of this invention,

' it is desirable to provide a manually controlled table traverse mechanism whereby the table 25 may be traversed longitudinallywith'out undue effort on the part of the operator. It is desirable, therefore, to provide a manually controlled, hydraulically actuated table traversing mechanism in which the speed of movement of a control member;A such as the rotation of a hand wheel, serves to control the rate of traversing movement of the table. As illustrated in the` drawings, the fluid pressure system is provided with a manually operated control valve |88. This valve is preferably a piston type valve comprising a valve stem |8| having formed integrally therewith valve pistons |82 and |83. Fluid under pressure from the pump 52 passes through pipe 53 and a pipe4|84 into a valve chamber |85 between the valve pistons |82 and 83. From the valv\e chamber |85, the uid under pressure may i pass outwardly through a pipe |86, into the cylinder chamber 6|, or may pass through a pipe 81 into the cylinder chamber 68, depending upon the position of the .valve stem 8|.

During the manually controlled traverse of the table 25, fluid under pressure isexhausted from the cylinder chamber 68, through pipe |81, into a valve chamber Y|88 formed between the valve piston |83 and the end of the valve |88, andout through a pipe |89-, into the reservoir 58. Similarly, when the fluid is exhausted from the cylinder chamber 6|, it passes outward-ly through the pipe |86, into a valve chamber 8, between the valve piston |82 and the other end of the valve valve stem IOI is connected to a slide block |I2 which slides within a slide frame I |3 fixed to the base I of the machine. The other end of the slide block 'I I2is provided with a rod ||4 which extends outwardly tothe other end of the slide frame II3. The slide block |I2 is normally held in a central position, to hold the valve 00 also in a central or neutral position, by means of a pair of opposed springs and ||6 (Fig. 2).

The springs |I5 and IIS-surround the rods I0| and I4, respectively, and are interposed between the opposite ,ends of the slide block |I2 andthe adjacent ends of the slide frame H3..

It is desirable to provide a means for adjusting the compression of the springs |I5 and 'I I0 so that theA slide block I|2 and the valve |00 may be held in the desired central or neutral position.

As illustrated in Fig. 2, a pairof adjustable bushings ||1 and II8 are screw threaded into the f slide frame I'I3 and have their inner ends engaging the outer ends of the springs ||5 and IIB,

respectively. By adjusting the bushings |I1 and ||8, the compression ofthe springs I|5 and ||6 may be varied as desired.

In order manually to control the table travverse, it is desirable to provide a manually operable hand traverse wheel |20 which is mounted on the outer end of a rotatable shaft |2|. shaft |2| is rotatably supported inthe slide block ||2. The inner end of the shaft |2| carries a gear |22 which meshes with a rack bar |23 depending from the under side of the table 25.

It is desirable, during the power reciprocation of the table 25, to render the manually controlled traverse mechanism ineective.- VThis is preferably accomplished by arranging the shaft |2| and f the gear |22 so that they may be moved axially accomplished by providing a valve I40 I(Fig. 1)

It is desirable to provide a suitable means f or rendering inoperative the automatically power controlledvreversing valve 45. This is preferably which isconnected by a link |\4| with the rod |04. Thevalve |40 is provided with passages |42 and |43 which are arranged during the power traversing' movement toallow free passage of fluid through the ports 58` and 63 respectively, to allow unrestricted ow of iluid underl pressure between the cylinder 40 and through the pipes The' 59 and 62, respectively, and controlled reversing valve 45.

When it is desired to traverse the table under manual control, the operator pushes the hand wheel |20 toward the right (Fig. 5) to compress the spring |24 and to throw the gear. |22 into mesh with the rack bar |23. The hand wheel |20 may then be rotated'in either direction to throw the slide block II2 and valve |00 from a central or neutral position and allow iluid under pressure from the pipe |04 and valve chamber |05 to pass either through the pipe |06 or the pipe |01, into the cylinder chambers 6I or 50, respectively. At the same time the slide block II2 moves to throw the valve |00 oi! the center or from a neutral position, the rod |I4, through the link |4| (Fig. 1), moves'the valve |40 from the position iuustratep i Fig. 1 so as to close the ports'or passages 50 and i3, respectively, and

thereby render'the table operated reverse coning valve 45 so that the table is reciprocated through a definite reciprocatory path, as controlled by the reversing lever 10 -and table dogs 12 and. 13, respectively. When it is desired to 'traverse the table under manual control, the stop and start andvspeed control valve 00 is actuated by shifting the control lever 92 into position 92a (Fig. 4) which serves tov close the V-port 83 and thereby stop theexhaust of iluid from the cylinder 40. 'I'he hand wheel |20 is then moved toward the right (Rig. 5) to shift the gear |22 from dotted line position |22a into full line position |22, to throw the gear |22 into mesh with the rack bar |23. The hand wheel may then be rotated in either a clockwise o r counterclockwise direction. The Irotation of the wheel trans- 'mits a rotary motion to the gear |22. The rack bar |23 being stationary, the gear |22 rolls on the rack bar vand the slide block I2 is thrown oi center against the compression of the balanced springs I|5 and IIB to throw the valve |00 voil? a central or neutral position and admit fluid under pressure through pipe |00 or |01 into the cylinder chambers 6I or 00, respectively, thereby starting the movement of the table 25. The rate of manual rotation of the feedwheel |20 serves to control the aperture of the valve |00 and thereby to control the Arate of movement of the table 25 under manual control. The faster the hand wheel '|20 is rotated,- the slide block ||2 and valve |00 willbe thrown to a greaterA extent ofi center, thereby allowing agreater flow offluid through either pipe |06 or pipe |01. When the rotation of the handv wheel |20 is reduced or released by the operator, the released tension of the spring II5 or the spring IIS serves to shift the slide block ||2 and the valve |00 to a central or neutral position, thereby stopping the ilow of uid under pressure to the cylirder 40 and consequently stopping the manually-\c'ontrolled traversing movement of the table 25. At the same time the valve |00 andslide block SI2 return to a neutral position,'the valve |40 is shifted to the position indicatedin Fig. l, thereby rendering the table control reversing valve operative so that the table' 25 may thereafer be operated under the automatic control of the table movement. When thel hand wheel I|20 -is released the automatic' table i 25 under the control ofthe table actuated revers-4 I2! is released and the shaft I2I, gear |22 and hand wheel 120 are shifted toward the left (Fig. 5) so that the gear i22 moves into dotted line position I22a, out of mesh with the table rack |23 during the automatic table traversing` or reclprocating movement,

I t will thus be seen that'there has been provided by this invention apparatus in whichthe various objects hereinabove set forth vtogether with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the 'above invention and as many changes mi-ght be made in the embodiment above set forth, it is to be understoodmt'hat all matter hereinbefore set forth or shovvrA in the accompanying drawings is to be interpre illustrative and not in a limiting sense."`

I claim: A l A l. In a machine tool, a longitudinally movable table, a iluid pressure operated piston and 'cylinder operativelyconnected to move said table longitudinally in either direction, and a manually operable table traversing mechanism including a control valve operatively connected to admit fluid under pressure to either end of said cylinder, yieldable means to hold said control valve in a central or neutral position, a manually operable control member which is movable bodily and is operatively connected to actuate said valve, and means including a rotatable gear connected with said member and a rack bar ixedly, connected with said table whereby the control Valve is actuated by' and the position thereof is controlled by the rate of movement of said control member.

2. In a grinding machine, a transversely movable rotatable grinding Wheel, a longitudinally movable table, a fluid pressure operated piston and cylinder operatively connected to move said ted ,as

y table longitudinally in either direction, and a v 'manually' operable table 'traversing mechanism including a control valve operatively connected to admit fluid under `pressure to either end of said cylinder, yieldable means to hold said control valve in a central or neutral position, `a manually operable rotatable hand wheel which is bodily movable and is connected toactuate said valve, and nieans including a rotatable gear connected Vwith said Wheel and a rack bar fixedly connected with said table whereby the control valve is actuated by and the position thereof is controlled by the rate'of rotation of' said hand wheel.

3. In a grinding machine, a transversely movable rotatable. grinding wheel, a longitudinally movable table, a fluid pressure operated piston and cylinder operatively connected to move said` table longitudinally in `either direction, and a manually operabletable traversing mechanism including a control valve operatively connected to admit fluid under pressure to either end of said cylinder,opposed balanced springs to hold said control valve in' a central or neutral position, a manually operable rotatable hand wheel, a movable support therefor which is connected to -actuate said valve, and means including a rotatable gear connected with said wheel which meshes with a rack bar xedly connected with said tablewhereby'the control valve is-actuated by and the position thereof is controlled by the rate of rotation of said hand wheel. A

4. In a grinding-machine, a transversely movable rotatable grinding Wheel, a longitudinally movablework table, a fluid pressure operated piston and cylinder operatively connected to move said table in either direction, and a manually operable table traversing mechanism including a control valve operatively connected to admit fluid under pressure to either end of said cylinder, a slide block operatively connected to move said control valve, a pair of opposed springsY able rotatable grinding Wheelfalongitudinally movable work table, a "fluid pressure operated piston land cylinder operatively: connected to move said table in either directiomand a manually'oper'able table traversing'mechanism including a control valve operatively connected to admit fluid under pressure to either end of said cylinder, a` slide block operatively connected to move said control valve, a pair of opposed springs to hold said slide block and said valve in a central or neutral position, a manually operable hand wheel rotatablyJ supported in said Vslide block, a gear operatively connected to rotate with said hand Wheel, a rack bar on saidtable, whereby the control valve is actuated by and the positicn'thereof is controlled by the rate of rotation of said hand wheel, and means to normally hold said gear out of mesh with said rack.

6. In a grinding machine, a base, a transversely movable grinding wheel, a longitudinallymovable table, a fluid pressure operated piston and cylinder to reciprocate saidtable, a reversing valve therefor, means including adjustable dogs on said tableautomatically to actnate said valve, a manually operable table reverse mechanism includ/ing a control valve operatively connected to admit fluid under pressure to either end of said cylinder, means to hold said control valve in a central or neutral position, means including a manually operable rotatable hand wheel whereby lthe control valve is actuated by and the -position thereof is controlled by the rate of rotation of the wheel, a shut-01T valve to render said reversing valve inoperative, and connections between the control valve and the shut-off valve whereby the reversing valve is rendered inoperative during the manual traverse of the table.

7. In a grinding' machine, a base, a transversely movable grinding wheel, a longitudinally movable table, a fluid pressure operated piston and cylinder to reciprocate said table, a reversing valve therefor, means including adjustable dogs -on said table automatically to actuate said valve,

a manually operable table traverse mechanism including a control valve operatively connected to admit fluid under pressure to either end of said cylinder, opposed balanced springs to hold said control valve in a central or neutral position, means including a manually operable rotatable hand wheel whereby the control valve is actuated by and the position thereof is controlledv by the rate of rotation of the hand Wheel, means to render said hand wheel inoperative during thel power reciprocation of the table, and connections betwen the control valve and the reverse -valve whereby thez'reverse valve is rendered inoperative during the manual traverse of the table.

8. In a grinding machine, a base, a transversely movable grinding Wheel, a longitudinallymovable table, a fluid pressure operated piston and 10 hand wheel whereby the control valve is actuated by and the position thereof is controlled by the rate of rotation of the hand wheel, means to render said hand wheel inoperative during the power reciprocation of the table, a shut-o valve torender said reversing valve inoperative. and connections between said control valve and shutoil valve whereby the reversing valve is renderd inelective during the manual traverse. of the table.

HERBERT s. rNDGEQ 1o