US2113363A - Grinding machine - Google Patents

Description

April 5, 1938. C, H, AMlDON 2,113,363

GRINDING MACHINE Filed Feb. e, 19:57

Patented Apr. 5, 1938 UNITED STATES GRINDING MACHINE Charles H. Amidon, Worcester, Mass., assignorgto Norton Company, Worcester, Mass., a rcorporation of Massachusetts Application February 6, 1937, Serial No. 124,450

Claims.

This invention relates to grindingmachines, and more particularly to a hydraulically operated cylindrical grinding machine.

One object of the invention is to provide a 5 simple, thoroughly practical hydraulically operated grinding machine. Another object of the invention is to provide an improved control mech` anism for a hydraulically operated grinding machine. Another object of the invention is to provide a hydraulically operated grinding machine with an interlocked fluid pressure and lmanual traverse control for the work table. Anotherobject of the invention is to provide a hydraulically operated grinding machine with an interlock between the control for the fluid pressure reciprocating mechanism and the manual traversing mechanism. Another object of the invention is to provide a fluid pressure reciprocating mechanism'for the work support which is controlled by a manually operable lever and arranged so that when the lever is thrown tol an operativerposition, the manual table traversing mechanism will be rendered inoperative. 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, andv the scope ofthe applicationof which will be in- 30 dicated in the following claims.

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

Fig. 1 is a iront elevation of the' improved grinding machine;

Fig. 2 is a fragmentary front view, on an enlarged scale, of the manual and hydraulic? table traverse controls, having parts broken away to show the interior construction;

Fig. 3 is a cross sectional'view, on an enlarged scale, taken approximately on'the line 3-3 ofv Fig. 1; and

Fig. 4 is a fragmentary diagrammatic 'pip-ing arrangement of the uid pressure table reciprocating mechanism.

A grinding machine embodying this invention comprises a base IJ=which supports a longitudinally movable table II on the usual V way (not shown) and a ii'at way 9 for a` longitudinal reciprocating movement relative to the base I0. A motor driven headstock I2 and a footstock I3 aremounted on the table II and are arranged rotatably to support a work piece on a headsto-ck center I4 and a footstockcenter I5 in operative Vrelation with arotatable grinding wheel 1G. The

grinding Wheel I6 is rotatably supported onta:- transversely movable wheel slide I1, of the vusualtype, such as for example'that shown in the ex-y plredUnited States patent to Norton No. 762,838l dated June 14, k1904. In the preferred form; an' 5,; electric motor 20 is mounted on the wheel slidel I1 and is provided with a pulley 2| which is con-4 nected by drivingbelts 22 with a pulley 23 on-the end of awheel spindle 24. f

A fluid pressure mechanism is provided tonre l mf ciprocate the table II. In the form illustrated; a cylinder 30 is lixedly mounted to the underside of the table I I. The cylinder-=3|l containsia piston 3| which is connected by apair of hollow-.piston rods 32jand 33, respectively, with a pair Aci? hollow 1;-,Y brackets`34-and 35,y respectively, which are fixed?1 on opposite ends of the base I0.

In the preferred construction, the base I lllsformed as Y al hollow, box-like yconstruction in i which the lower portion of the base serves' as a? reservoir 40 for the fluid pressure system. Fluid is drawn from--the-reservoir l40-through a pipe 4| by a pump 42 and is forced through a pipe 43 and;- a pipe 44 -to a table-control valve 45.` A fluidA pressure relief valve 46 is provided in thev pipe 43 andv ls arranged to allow Ifluid under pressure to x pass through a -pipe'4'l and returntothe reservoir 40in'case the luidpressure within the system increases above a desired pressure.

The control valve`45'has 4been illustratedonly 30 diagrammatically, since'this featureis lnot considered to be part of the present invention; For a detailed disclosure of the control valve 45 andl also theuid pressure system, reference may be had tothe United States Patent No. 2,071,677 to 35.

Wallace H. Wood dated February 23, 1937. The reversing valve 45 is arranged to combine the functions of a reversing valve and Va pilot valve, so that a lever actuated by thetablemovement serves to move the valve only to a center position 40 and then fluid under pressure serves to move the reverse valve into a reverse position, producing a smooth reversal of the table without the necessity of providing a complicated series of valve mecha# nisms and pipe connections: A pivotally mount- 45- through the bracket 35 and the hollow piston rod 55 33 and into a cylinder chamber 62 to move the cylinder 30 an-d the table toward the right (Fig. 4) During the movement of the table toward the right, fluid exhausts from a cylinder chamber 63, through the hollow piston rod 32, a pipe 64, a pipe 65, into a chamber 66 in the control valve 45, and out through a pipe 61, through a throttle port 68 in a control valve 69, and exhausts through a pipe 10 into the reservoir 40. A valve piston 1| in the control valve 68 has an angled-off end face which may be rotated to regf ulate the aperture of the port 68 so as toV control the speed of movement of the table A valve stem 12 of the valve 69 is provided with a control knob 13 by which the valve may be rotated to control the table speed. The valvestem 12 is arranged so that the valve may be moved endwise from a stop to a start position by means of a control lever 15 which is pivotally mounted on a stud 16. The lever 15 is connected to the valve stem 12 so that the valve stem 12 may be moved endwise to open or close the port 68 to. stop or start the fluid pressure movement of the table When the control valve 69 is moved toward the left (Fig. 4) to stop the fluid pressure movement of the table, a by-pass groove 18 in the valve 69 connects the pipe 65 with ther pipe 6| to permit by-passing of fluid between the cylinder chambers 62 and 63 to facilitate manual traversing of the table when desired.

A manually operable table traverse mechanism is provided for manually traversing the table longitudinally relative to the base I0. This mechanism, as illustrated, is preferably of a two-speed type, such as that disclosed in the prior United States Patent No. 1,299,765 to Norton and Turner dated April 8, 1919. The table is provided with a depending rack bar which meshes with a gear 8| slidably keyed to a rotatable shaft 82. The shaft 82 is supported in bearings 83 and 84 in the apron 52. A large gear 85 is keyed to the outer end of the shaft 82. A manually operable hand traverse wheel 86 is rotatably mounted on an outwardly extending shaft 81 which is fixed to the apron 52. The hand wheel 86 carries a rotatable shaft 88 having formed integrally thereon a gear 89 which meshes with an internal gear 90. The gear 90 is mounted on the hub of a gear 9| which is rotatably mounted on the shaft 81. The shaft 88 rotatably supports a gear 92 meshing with a non-rotatable internal gear 93 which is fixed relative to the apron 52. When the hand wheel 86 is rotated to traverse the table this motion is transmitted through the gear 89 to rotate the gear 90 at the same speed at which the hand wheel 86 is rotated to transmit a rotary motion through the gear 9| and through the gear 85 to rotate the shaft 82 and the gear 8| to cause a longitudinal traversing movement of the table The outer face of the .gear 92 is provided with clutch teeth (not shown) which are arranged to be engaged by a clutch member 94 which is actuated by a knob 95. The clutch member 94 is slidably keyed to the shaft 88 and is arranged to be moved into and out of operative engagement with the clutch teeth on gear 92 by means of the knob 95. If a slow traversing movement of the table is desired, such as for traversing a diamond or truing tool at a slow uniform rate across the fac'e of the grinding wheel I6, the knob 95 is pushed toward the left (Fig. 3) so that the clutch member 94 is thrown into engagement with the clutch teeth on the gear 92. In this position of lthe parts, rotation of the hand wheel 86 revolves the gears 89 and 92 and the shaft 88. The pinion 92 meshing with the fixed internal gear 93 is thereby forced to rotate, turning the gear 89 with it, which in turn rotates the internal gear 90 and causes a differential movement between 5 the parts, this movement being transmitted to the gears 9| and 85 to rotate the shaft 82 at a slow speed, which motion is transmitted through the gear 8| to the rack 80. Full details of this mechanism have not been illustrated or described in the present case, since this feature in itself is not considered part of the present invention. For complete details of construction of the manually operable table traverse mechanism, reference may be had to the above-mentioned United States 15 Patent No. 1,299,765.

It is desirable to provide a suitable interconnection between the hydraulically operated table reciprocating mechanism and the manually operable traverse mechanism so that when the table ls reciprocated by means of the table control fluid pressure mechanism, the manually operable traverse mechanism will be rendered inoperative so that the manually operable traverse wheel 86 remains stationary during the power reciprocation of the table I. This is preferably accomplished by slidably keying the gear 8| on the shaft 82 so that it rotates therewith but may be moved endwise into and out of mesh with the rack bar 80. A spring |00 surrounds the shaft 82 and ls interposed between the gear 48| and a flange |0| on the shaft 82. The compression spring |00 normally holds the gear 8| in mesh with the rack 80. A head |02 on the end of the shaft 82 serves to locate the gear 8| relative to the rack 88 and to limit its motion when thrown into mesh therewith.

In order to throw the gear 8| out of mesh with the rack 80 when desired, a bell crank lever |05 is pivotally mounted on a stud |06 within the base |0 of the machine. The upper end of an arm |01 of the bell crank lever |05 is formed as a yoked member |08 which straddles a hub on the gear 8|. The yoked member |08 is provided with diametrically opposed, inwardly projecting pins |09 which ride in a groove ||0 in the hub of the-gear 8|. It will be readily appreciated that when the bell crank lever |05 is rocked in a clockwise direction (Fig. 3), gear 8| will be moved against the compression of the spring |00 into dottedline position 8|a, out of mesh with the rack bar 80.

In order to disengage the gear 8| when the control lever 15 is thrown into the position illustrated in Fig. 4 to start the table traverse under uid pressure, a cam mechanism is provided which is actuated by the control lever 15. A lever |20 (Fig. 3) is mounted on the stud 16 and is either formed integral with or fixed to the lever 15 so that when the lever 15 is shifted, the lever |20 will be moved through acorresponding extent. A cam |2| is formed on the upper end of a lever |22 which is pivotally mounted on a stud |23 carried by the base |0. 'I'he cam |2| is arranged to engage a follower roller |24 carried on an armi 65 |25 of the beu crank |05. The lower end of the' lever |22 is connected by a stud |26 with one end of a link |21. The other end of the link |21 is connected by a stud |28 with the lower end of the lever |20. When the lever 15 is moved in a clockwise direction (Fig. 2) to open the control valve 69 and start the movement of the table under control of the iiuid pressure mechanism, the lever |20 is also rocked in a clockwise direction, causing the link |21 to move toward the left (Fig. 3), thereby rocking the lever |22 on its supporting stud |23 in a clockwise direction. This movement causes the cam |2| to move in a clockwise direction, which in turn transmits a clockwise'rocking movement ofthe bell crank |05 to throw the gear 8| out of mesh with the rack 80, thereby rendering the manually operable hand wheel 86 inoperative and allowing it to remain stationary during the fluid pressure traversing or reciprocating movement of the table The cam |2| is so shaped that when the lever |22 is I'noved in a clockwise direction (Fig. 3), the rise on the cam causes the bell crank lever |05 to be rapidly moved in a clockwise direction, thereby quickly disengaging the gear 8| from the rack 80. The cam |2| is provided with a portion which is concentric with the stud |23 which serves to lock the bell crank' |05 against the compression of the spring so as to hold the gear 8| out of mesh with the rack 80 until the control lever 'l5 is again shifted to stop the fluid pressure reciprocating movement of the table The grinding wheel slide and grinding wheel I6 are arranged for a transverse feeding movement to feed the wheel toward or from the work piece being ground to produce the desired feeding action. A manually operable feed wheel |20 is mounted on the front of the machine base and is operatively connected through a gear mecha- `nism and nut and screw mechanism (not shown) to feed the grinding wheel transversely as desired. The details of this mechanism have not been fully illustrated in the present application since this feeding mechanism is not considered a part of the present invention. 'Ihis feed is substantially identical to that shown in the prior United States patent to Norton No. 762,838 dated June 14, 1904. to which reference may be had for further details of construction. The feed wheel |20 may be operated manually or, if desired, it may be actuated by means of a feed pawl |2I.

The operation of this mechanism will be readily apparent from the foregoing disclosure. When it is desired to traverse the table manually, the

control lever 'l5 is positioned as illustrated in Fig. 3, so that the gear 8| is in mesh with the rack '|0. In this position of the parts, the hand wheel 86 may be rotated and through the two-speed mechanism above described, the table may be traversed either at a comparatively slow rate or at a fast rate, as desired. When it is desired to traverse or reciprocate the table by the fluid pressure mechanism, the control lever 15 is rocked in a clockwise direction from the position illustrated in Fig. 3 into the position illustrated diagrammatically in Fig. 4, which serves to open the port 68, thereby starting the table reciprocation by il'uid under pressure. During the shifting movement of the control lever 15, the cam |2| rocking in a clockwise direction rocks the bell crank lever |05 also in a clockwise direction to disenga-ge the gear 8| from the rack 80, thereby rendering the manually operable traverse mechanism inoperative and allowing the hand wheel to remain stationary during the power traverse of the table.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinbefore set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made n the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown inthe accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

I claim:-

1. In a grinding machine, a longitudinally movable table, a hydraulically operated reciprocating mechanism therefor, a stop and start valve Vto 'control the hydraulic mechanism, a manually operable control lever to actuate said valve, a manually operable table traverse mechanism including a rotatable hand wheel and a rack and gear mechanism, s aid gear being arranged to move into and out of mesh with said rack, yieldable means normally to maintain said gear in mesh with said rack, means including a pivotally mounted cam operatively connected to move said gear out of mesh with said rack, and connections between said lever and cam whereby the cam is moved to disengage said gear when the lever is moved to start the hydraulic table traversing mechanism, said cam being arranged t0 lock said gear out of engagement with said rack during the hydraulic traversing movement.

2. In a grinding machine, a longitudinally movable table, a hydraulically operated reciprocating mechanism therefor, a stop and start valve to control the hydraulic mechanism, a manually operable control lever to actuate said valve, a manually operable table traverse mechanism including a rotatable hand wheel and a rack and gear mechanism, said gear being slidably mounted so that it can be moved into or out of mesh with said rack, a spring normally to maintain said gear in mesh with said rack, a pivotally mounted bell crank lever, a yoke formed on one arm of said bell crank lever which is operatively connected to move said gear, a follower roller on the other arm of said bell crank lever, a pivotally mounted cam, and a link connecting said cam with said control lever whereby said cam rocks said bell crank lever to throw the gear out of mesh with the rack when the control lever is moved to start the hydraulic table traversing movement, said cam being arranged to lock said gear out of mesh with the rack during the hydraulic traversing movement.

3. In a grinding machine, a longitudinally movable table, a hydraulically operated reciprocating mechanism therefor, a stop and start valve to control the hydraulic mechanism, a manually operable control lever to actuate said valve, a manually operable table traverse mechanism including a rotatable hand wheel and a rack and gear mechanism, yieldable means normally to maintain said gear in mesh with the rack, means including a bell crank lever operatively connected to move said gear out of mesh with the rack, and means including a cam actuated by said lever to move said bell crank lever to shift the gear out of mesh with the rack when the hydraulic table reciprocation is started, said cam being so shaped and arranged as positively to lock said 'gear out of mesh with the rack during the hydraulic table traversing movement.

4. A grinding machine comprising a rotatable grinding wheel, a rotatable work support, a longitudinally movable table for said support, means to move said grinding wheel and Work support transversely relative to each other, manually operable means including a rack and gear mechanism to traverse said table longitudinally, yieldable means normally to maintain said gear in mesh with said rack, a fluid pressure system including a piston and cylinder operatively connected to reciprocate said table longitudinally,

means including a reversing valve to change the direction of movement of the table, a control valve which serves in one position to control the speed of movement of the table and in a second position to stop the flow of fluid to and from said table and to permit by-passing fluid from one end of the cylinder to the other, a manually operable lever to actuate said control Valve, and a cam actuated by said lever to throw said gear out of mesh with the rack when the control valve is opened to start the table movement.

5. A grinding machine comprising a rotatable grinding wheel, a rotatable Work support, a longitudinally movable table for said support, means to move said grinding Wheel and Work support transversely relative to each other, manually operable means including a rack and gear mechanism to traverse said table longitudinally, a spring normally to hold said gear in mesh with said rack, a uid pressure system including a piston and cylinderi operatively connected to reciprocate the table longitudinally, means including a reversing valve to change the direction of movement of the table, a control valve which serves in one position to control the exhaust of iiuid from said cylinder to regulate the power movement of said table and in a second position to shut off said uid flow and to permit a by-pass of fluid from one end of the cylinder to the other during a manual traverse of said table, a pivotally mounted bell crank lever operatively connected to move said gear against the tension of said spring, a manually operable lever operatively connected to actuate said valve, and a cam actuated by said lever to rock said bell crank when said control valve is moved to an open position to throw said gear out of mesh with said rack.

CHARLES H. AMIDON.

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