US2121730A - Grinding machine-work loading and driving mechanism - Google Patents

Description

June 21, 1938. COLE 2,121,730

GRINDING MACHINE-WORK LOADING AND DRIVING MECHANISM Filed Nov. 29, 1937 2 Sheets-Sheet 1 RAYMOND A. COLE June 21, 1938. R. A. COLE 2,121,730

GRINDING MACHINE-WORK LOADING AND DRIVING MECHANISM Filled Nov. 29, 1937 2 Sheets-Sheet 2 RAYMOND A. COLE Patented June 21, 1938 PATENT OFFICE GRINDING MACHINE-WORK LOADING AND DRIVING MECHANISM Raymond A. Cole, Worcester, Mass., assignor to Norton Company, Worcester, Mass, a corporation of Massachusetts Application November 29, 1937, Serial No. 177,019

10 Claims.

The invention relates to grinding machines, and more particularly to a work loading and driving mechanism for a cylindrical grinding machine.

One object of the invention is to provide a simple, thoroughly practical work loading and driving-mechanism for a cylindrical grinding machine whereby the work piece may be driven from its center portion while the two end portions thereof are ground by a pair of spaced rotatable grinding wheels. Another object of the invention is to provide a work loading and driving attachment having a pivotally mounted work driver and carrier which is arranged to swing to and from an operating position to facilitate loading and unloading work pieces therein. It is another object of this invention to provide a work loading and driving attachment for a cylindrical grinder which may be adjustably positioned on a standard cylindrical grinding machine. A further object of the invention is to provide a work loading and driving attachment comprising a hollow driving member which is adapted to receive a work piece to be ground and having driving means carried thereby for engaging a central portion of the work piece to drive the same during a grinding operation.

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 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 cross sectional View through a cylindrical grinding machine, showing the improved work loading and driving mechanism;

Fig. 2 is a longitudinal sectional view, on an enlarged scale, taken approximately on the line 2-2 of Fig. 1, showing the work loader and driver in an operating position and showing the driving mechanism /for rotating the work piece;

Fig. 3 is a fragmentary view on a reduced scale, showing the grinding wheel feed mechanism;

Fig. 4 is a cross sectional view, taken approximately on the line 4-4 of Fig. 2, showing the work loading and driving mechanism in an operating position;

Fig. 5 is a fragmentary sectional view, on an enlarged scale, taken approximately on the line 5-5 of Fig. 4, showing the work receiving portion of the work loader and driving member;

Fig. 6 is a cross sectional view, on an enlarged scale, taken approximately on the line 6-6 of Fig. 4, showing the locking mechanism for maintaining the work loader and driver in an operating position;

Fig. 7 is a fragmentary sectional view, taken approximately on the line 1-1 of Fig. 6, showing the parts of the locking mechanism in elevation;

Fig. 8 is a plan view of a modified form of the work driving mechanism; and

Fig. 9 is a sectional view taken approximately on the line 9-9 of Fig. 8, showing the work driving dogin elevation.

A grinding machine has been illustrated in the drawings comprising a base In which supports a longitudinally movable work supporting table H on the usual V-way i2 and fiat way IS. The table ll may be traversed longitudinally relative to the base M1 to position a work piece supported on said table in the proper relation with the grinding element. The table I I may be traversed either mechanically, as shown in the expired U. S. Patent No. 762,838 dated June 14, 1904, or it may be traversed manually, as shown in Fig. 1 of the drawings, by means of a manually operable traverse wheel I I which is supported on the outer end of a rotatable shaft 15. The shaft I5 is supported in a bearing IS on the base I II and carries at its inner end a gear I! which meshes with a rack bar l8 depending from the table II.

A rotatable grinding wheel 20 is supported on a wheel spindle 2| which is rotatably supported in bearings (not shown) in a transversely movable wheel slide 22 supported on the usual V and fiatways on the base In of the machine. The grinding wheel 20 and its supporting spindle 2| may be rotated by a pulley 23 mounted on the outer end of the spindle 2| which is driven by means of a belt 24 from a suitable source of power, such as a motor (not shown) mounted on the upper surface of the wheel slide 22.

The wheel slide 22 is arranged to be fed toward and from the table II by means of a feeding mechanism which comprises a half nut 25 depending from the under side of the slide 22 which meshes with or engages a rotatable feed screw 26 journalled in suitable bearings 21 and 28 in the base ill of the machine. The feed screw 26 carries a gear 29 at its forward end which meshes with a pinion 30 mounted on the inner end of a rotatable shaft 3|. The outer end of the shaft 3| supports a gear 32 which meshes with a gear 33 mounted on the inner end of a rotatable shaft 34. The shaft 34 carries a manually operable feed wheel 35 on its outer end. The feed wheel is provided with a micrometer adjusting mechanism 36 to facilitate fine adjustment of the infeeding movement of the grinding wheel. The feed wheel 35 and micrometer mechanism 36 are substantially identical to that shown in the prior patent above mentioned, to which reference may be had for further details of disclosure not contained herein. The feed wheel 35 may be actuated manually or may be actuated mechanically by a reciprocating pawl mechanism, such as is shown in the prior Patent ported by the wheel spindle 2|.

No. 1,443,924. This mechanism is not considered to be a part of the present invention and consequently it has not been shown in detail.

This 'mproved mechanism is particularly adapted for grinding portions adjacent each end of a work piece to the desired cylindrical size and form and the grinding element 26 preferably comprises two spaced grinding wheels 20 and 20a, as shown in Fig. 2. The wheels 26 and 20a are preferably mounted on asleeve 38 which is sup- A spacing sleeve 39 carried by the wheel sleeve 38 is of the proper length to space the wheels 26 and 26a the required distance apart for grinding the desired portions of a work piece.

A work piece such as a motor armature shaft 40 having an armature 4| mounted thereon is arranged to be supported on a headstock center 42 and a footstock center 43. The footstock center 43 is mounted on a footstock (not shown) which is supported on the work table II. This footstock is not considered to be a part of the present invention and consequently it has not been illustrated in detail. This footstock may be of the type shown in the prior mentioned expired U. S. Patent No. 762,838 dated June 14, 1904.

The headstock center 42 is mounted within a headstock spindle 44 which is in turn supported in a headstock- 45 which is mounted on the work table i I. In the preferred construction the headstock is of a dead center type, that is, it is so constructed and arranged that the center 42 and its supporting spindle 45 do not rotate during the grinding operation.

' A face plate 46 is rotatably supported and in the preferred construction is fixedly mounted to rotate with a driven pulley 41 which is rotatably supported on a bearing 48. The face plate is arranged so that it may be positively rotated during the grinding operation to transmit a rotary motion to the workpiece 40. In the preferred form of this mechanism, a motor driven headstock is employed having an electric motor 51 mounted on the upper surface of the headstock 45. The motor 51 is provided with a pulley 49 which is connected by a multiple vbelt 50 with a pulley 51 which is keyed to a rotatable sleeve 52. The sleeve 52 is rotatably supported on a rotatable shaft 53 which is journailed in a bearing 54 within the headstock frame 45 at one end. The other end of the shaft 53 rotates within the sleeve 52 as a bearing. A pulley 55 is keyed to the end of the shaft 53 and is connected by a multiple V-belt 56 with the pulley 41 which drives the face plate 46.

In order to facilitate ready stopping and starting of the face plate 40, a clutch mechanism is provided which may be manually operated in the manner shown in the prior U. S. patent to Belden No. 1,631,458 dated June '7, 1927, to which reference may be had for further details of disclosure. As illustrated in Fig. 2 of the drawing's, the clutch comprises an outer clutch member 60 which is formed integral with the sleeve 52 and an inner clutch member 6| which is formed integral with a sleeve 62 which is slidably keyed to the shaft 53. The clutch member 60 has an internal frusto-conical clutching surface which is arranged to mate with an external frusto-conical surface on the periphery of the clutch member 6|. It will be readily apparent from this disclosure that when the clutch member 6| is in the position illustrated in Fig. 2, power from the motor 51 will be transmitted through the belt drive above described to rotate the clutch member 60 which in turn rotates the clutch member 6! and the shaft 53 to transmit a rotary motion to the face plate 46. A yoked member 64 actuated by a manually operable lever 63 (Fig. 1) serves to engage a clutch shifting ring 65 which slides within a groove 66 between the clutch member 6| and a flanged member 61 supported on the sleeve 62.

A compression spring 68 surrounding the shaft 53 and interposed between the end of the sleeve 62 and a collar 69 pinned to the shaft 53 serves normally to hold the clutch member 61 in driving engagement with the clutch member 60. The yoked member 64 is shifted to move the ring 65 toward the right (Fig. 2), thus compressing the spring 68 and withdrawing the clutch member 6| from engagement with the clutch member 66 to disconnect the drive of the motor and thereby stop the rotation of the face plate 46. A friction ring is interposed between the ring 65 and the flange 61, which serves to retard the rotation of the shaft 53 so as quickly to stop the rotation of the face plate 46.

In grinding a work piece having two end portions to be ground. it is not feasible to drive the same from the headstock end in the usual manner since there is no way of clamping a driving dog on the end of the work piece. In order to obtain the main object of this invention it is, therefore, desirable to provide a work loading and driving attachment whereby the work may be readily moved into an operating position with the centers 42 and 43 and may be rotated by a driving element which engages a central portion of the work piece to be ground. As illustrated in the drawings, a work loading and driving attachment 16 is adjustably mounted on a bracket 1| which is clamped to the upper surface of the table II. The attachment 10 is provided with elongated slots through which clamping bolts 12 pass. These clamping bolts are screw threaded into the bracket 1! and are arranged to clamp the attachment and bracket in adjusted position. The frame 10 of the attachment is provided with an upwardly extending housing 13 within which is journalled a rotatable sleeve 14 having formed integral therewith an outwardly extending arm 15. The arm 15 in turn supports a bracket 16 by means of clamping screws which pass through elongated slots in the bracket 16 and are screw threaded into the arm 15. The end of the bracket 16 is provided with a longitudinal extending boss 11 which has a central aperture 18 of sufficient size to receive an armature shaft 46 therewithin. The sleeve 11 supports an'anti-friction ball bearing 19 which in turn supports a pulley 80. The pulley 80 may be driven by a V-belt 8| from a pulley 82 supported on a rotatable shaft 83 which is journalled at one end in a bearing 64 within the sleeve 14 and at the other end in a bearing 85 which is supported in the housing 13. The other end of the shaft 83 carries a pulley 86 which is connected by a V-belt 81 with a V-pulley 88 fixedly mounted on the face plate 46. The bracket 16 may be'adjusted relative to the arm 15 to provide the desired tension on the V-belt 8I.

It will be readily apparent from the foregoing disclosure that the sleeve 14 and the arm 15 formed integral therewith and bracket 16 may be readily swung from a full line position (Fig. 4) into a broken line position 16a (Fig. 4) without affecting the drive to the pulley 88. It will be readily apparent from the foregoing disclosure that power from the motor 51 will be transmitted through the clutch 68,6I, the shaft 53, the belts 56, to the face plate 46, and from the face plate, by the pulley 88 and belt 81, to the pulley 86 on the shaft 83 which in turn rotates the pulley 82 and the pulley 88 which surrounds the work piece to be ground.

In order to rotate the work piece during the grinding operation, it is desirable to provide a suitable work driving mechanism which may be rotated with the pulley 88 and which is arranged to transmit a rotary motion to the armature shaft 48. In the preferred form, a driving plate 98 is mounted on the side face of the pulley 88. The driving plate 98 is provided with enlarged holes 9I and 92 through which the screws 93 and 94 pass. The screws 93 and 94 pass through apertures in a plate 95 and are screw threaded into a plate 96 which is supported in a recessed portion on the opposite side of the pulley 88. By means of the screws 93 arid-94, the plates 95 and 98 may be clamped rigidly in place to support the pulley 88 on the outer race of the anti-friction bearing 19. Nuts 91 are mounted on the outer ends of the screws 93 and 94 and serve to hold the driving plate loosely in position on the side face of the collar 96. Due to the looseness of -the adjustment of the nuts 91, and also to the enlarged holes 9I and 92, the driving plate 98 is free to move relative to the pulley 88. i

The driving plate 98 is preferably provided with suitable work engaging members which drivingly engage a portion of x the work piece, either by clamping the driving plate 98 thereto or, as iilustrated in Fig. 5, bymeans of two diametrically opposed driving pins 98 and 99 which are fixedly mounted on or formed integral with the driving plate 98. As illustrated in Fig. 5, the driving pins 98 and 99 engage apertures I88 and IM within the armature 4| carried by the armature shaft- 48 so that when the pulley 88 is rotated, the rotary motion will be transmitted through the driving plate 98 and the driving pins 98 and 99 to rotate the work piece or armature shaft 48. Due to the floating arrangement of the driving plate 98, the drive of the driving element on the work will be equalized at diametrically opposite points, thereby eliminating any tendency to deflect the work piece from its normal rotation during grinding.

It is desirable to provide a suitable latch mechanism whereby the work loader may be locked in an operating position. The arm 15 is pref erably provided with an upwardly extending. portion I82 which supports a boss I83. The boss I83 carries a rotatable stud I84, the other end of a which carries a rod I and anactuating knob I86.

A short arm I81 is either formed integral with or 7 arranged to move with the rod I85 and is arranged to be rocked therewith into a clamping position to lock the attachment in an operating position. The arm I81 carries an adjustable screw I88 which is arranged to be swung into engagement with a cam or wedge-shaped surface I89 formed in the upper surface of the attachment housing 13. In the position of the parts as shown in Fig. 6, the screw I88 is in locked engagement with the cam I89. After the grinding operation has been completed, the knob I88 is grasped by the operator and swung in a clockwise direction, moving rod I85 into position I85a which in turn serves to rock the arm I81 into position I81a (Fig. 6) to release the locking element, after which the knob I86 may be moved in a clockwise direction (Fig. 4) to swing the driving pulley 88 and its associated parts into position 88a to facilitate removal of the finish ground piece of work and insertion of a new piece of work therein.

The above described mechanism for driving a work piece is particularly intended for use in' driving work pieces having an enlarged central portion thereon which either is provided with holes passing therethrough, as illustrated in Fig. 5, or has projecting portions thereon which may be engaged by the driving pins 98 and 99. This work loading and driving attachment is not limited to this particular class of work but may be readily utilized for grinding the end portions of any cylindrical work piece. As shown in the modification illustrated in l igs. 8 and 9, a driving dog I28 may be clamped on the work piece 48 by means of a clamping screw I2I. The dog I28 has diametrically opposite projecting driving pins I22 and I23 which are of sufllcient length to be engaged by the driving pins 98 and 99, respectively. In the use of this driving dog I28, the dog is clamped on the work piece so that the projecting pins I22 and I23 will be located in the path of the driving pins 98 and 99, respectively, when the work piece is swung into an operative position and supported by the headstock center 42 and footstock center 43. It will be readily appreciated from the foregoing disclosure that practically any cylindrical work piece having opposed end portions to be ground simultaneously may be ground by means of this attachment.

The operation of this improved grinding attachment will be readily appreciated from the foregoing disclosure. A work piece such as an armature shaft 48 is inserted within the aperture 18 in the sleeve 11 with the driving pins 98 and '99 inserted within the holes I88 and I8I within the armature 4|, while the pulley 88 and its associated parts are in an inoperative position, as shown in dotted lines in Fig. 4, after which the knob I88 is moved from dotted line position I88a into full line position I86, which serves to swing the driving pulley 88 and its associated driving parts into an operating position, as illustrated in full lines in Fig. 4. An adjustable stop screw II2 carried by a boss II 3 formed integral with the bracket H is arranged in the path of the arm 15 and serves to determine the operating position of the sleeve 18 so as to position the armature shaft 48 substantially in alignment with the headstock center 42 and footstock center 49.

When the pulley 88 and the associated driving plate 98 is moved into an operating position, the rootstock center 43 may be moved into engagement with the end of the work so as to grip the work piece between the headstock center 42 and the rootstock center 43. The movable work driving clutch'member GI may then be thrown into engagement with the clutoh'member 68 to start the rotation of the armature shaft 48 through the driving mechanism previously described. The grinding wheels 28 and 28a as well as the wheel slide 22 may then be fed toward the work piece ly manually rotating the feed wheel 85 to grind a pair of spaced end portionsllll and Hi adjacent to the opposite ends of the armature shaft 40 to the desired predetermined size. After the portions H0 and Hi have been ground to the desired size, the grinding wheels are moved away from engagement with the work by means of the rotation of the feed wheel 35 and the footstock center is withdrawn and the work loader is then unlocked and rocked to a loading position so that the ground armature shaft 40 may be readily removed therefrom and a new work piece inserted therein.

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 drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:-

1. In a grinding machine having a pair of spaced rotatable grinding wheels arranged simultaneously to grind end portions of a cylindrical work piece, a rotatable work support including a headstock and footstock center, and a work loading and driving mechanism including a pivotally mounted arm, having a work receiving aperture adjacent to the end of said arm, a rotatable member supported on said arm and surrounding said aperture, and a work driver carried by said member which is arranged to drive the work piece at a point midway between its ends.

2. In a grinding machine having a plurality of spaced rotatable grinding wheels which are arranged simultaneously to grind spaced end portions on a work piece, a rotatable work support including a headstock and footstock center, and a work loading and driving mechanism including a pivotally mounted arm, an enlarged portion on the end of said arm having a work receiving aperture therein, a rotatable member rotatably supported on said portion, and a work driver carried by said member which is arranged to engage and drive a work piece, said rotatable member and work driver being located between said grinding wheels.

3. In a grinding machine having a plurality of spaced grinding wheels which are arranged simultaneously to grind a plurality of portions on a work piece, a rotatable work support including a headstock and footstock center, and a work loading and driving device including a pivotally mounted arm, a hollow end portion on said arm extending at right angles to said arm, having a work receiving aperture therein, a rotatable member supported on said end portion and sur rounding the work piece, a work driver carried by said member which is arranged drivingly to engage the work piece midway between said centers, and manually operable means to swing said arm into an operating position so that the work receiving aperture is in axial alignment with the centers.

4. In a grinding machine having a plurality of spaced grinding wheels which are arranged simultaneously to grind a plurality of portions of a work piece, a rotatable work support including a headstock and footstock center, and a work loading and driving device including a pivotally mounted arm, a hollow end portionon said arm extending at right angles to said arm, having a workreceiving aperture therein, a rotatable member supported on said 'end portion and surrounding the work piece, a work driver carried by said member which is arranged drivingly to engage the work piece midway between said centers, manually operable means to move said arm into an operating position with said aperture in axial alignment with said centers, and means positively to lock said arm in an operating position 5. In a grinding machine, a pair of spaced rotatable grinding wheels, a rotatable work support including a headstock and footstock center, means to feed said grinding wheels transversely toward and from said work support, and a work loading and driving device including a pivotally mounted arm, an enlarged end portion on said arm, having a work receiving aperture in said portion, an anti-friction bearing supported on said portion, a driving pulley carried by said bearing, and a driving plate carried by said pulley and having projections thereon which are arranged to engage a portion of said work-piece midway between said centers.

6. In a grinding machine, a pair of spaced rotatable grinding wheels, a rotatable work support including a headstock and footstock center, means to feed said grinding wheels transversely toward and from said work support, and a work loading and driving device including a pivotally mounted arm, an enlarged end portion on said arm, having a work receiving aperture in said portion, an anti-friction bearing supported on said portion, a driving pulley carried by said bearing, a driving plate carried by said pulley and having projections thereon which are arranged to engage a portion of said work piece midway between said centers, and manually operable means to swing said work loading device to a loading station to facilitate insertion and removal of work before and after grinding.

7. In a grinding machine, a pair of spaced rotatable grinding wheels, a rotatable work support including headstock and footstock centers, means to feed said wheels transversely toward and from said work support, and a work loading and driving device including a pivotally mounted arm which is arranged to swing from a loading to a grinding position in axial alignment with said centers, an enlarged end portion on said arm, having a work receiving aperture in said portion, a bearing on said portion, a driving pulley car ried by said bearing, a floating driving plate carried by said pulley which is arranged to engage and rotate said work piece, and means to rotate said pulley.

8. In a grinding machine, a pair of spaced rotatable grinding wheels, a rotatable work support including headstock and footstock centers, means to feed said wheels transversely toward and from said work support, and a Work loading and driving device including a pivotally mounted arm which is arranged to swing from a loading to a grinding position in axial alignment with said centers, an enlarged end portion on said arm, having a work receiving aperture in said portion, a bearing on said portion, a driving pulley carried by said bearing, a driving plate carried by said pulley which is arranged to engage and rotate said work piece, an electric motor, and driving connections between said motor and pulley to rotate said pulley and thereby rotate the work during the. grinding operation.

9. In a grinding machine, a pair of spaced rotatable grinding wheels, a rotatable work support including headstock and footstock centers, a rotatable face plate on said headstock, means including an electric motor to rotate said face plate, means to feed said grinding wheels transversely toward andfrom said work support, and a work loading and driving device including a pivotally mounted arm arranged to be swung from a loading to a grinding position, an enlarged end portion on said arm, having a work receiving aperture in said portion, a bearing supported on said portion, a driving pulley supported by said bearing, a driving plate driven by said pulley and having projections to drive a work piece midway between its centers, and driving connections between said face plate and said pulley for rotating the same during a grinding operation.

10. In a grinding machine, a pair of spaced rotatable grinding wheels, a rotatable work support including a headstock and footstock center, a rotatable face place on said headstock, means to rotate said face plate, means to feed said grinding wheels transversely toward and from said work support, and a work loading and driving device including a pivotally mounted arm, an enlarged end portion on said arm, having a work receiving aperture in said portion, an anti-friction bearing supported on said portion, a driving pulley carried by said bearing, a work driving plate carried by said pulley having projections thereon arranged to engage and drive a work piece midway between its ends, a rotatable shaft axially aligned with the pivot for said arm, driving connections between said face plate and said shaft, and driving connections between said shaft and the work driving pulley.

RAYMOND A. COLE.

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