US2244643A

US2244643A - Grinding machine-swivel table adjustment

Info

Publication number: US2244643A
Application number: US233912A
Authority: US
Inventors: Carl G Flygare
Original assignee: Norton Co
Current assignee: Saint Gobain Abrasives Inc
Priority date: 1938-10-08
Filing date: 1938-10-08
Publication date: 1941-06-03
Anticipated expiration: 1958-06-03

Description

'June 3, 1941. c. G. FLYGARE 2,244,543

' GRINDINQ MACHINE =S WIVEL TABLE ADJUSTMENT Filed Oct. 3, 1938 s Shee ts-Sheet 1 FIEJ 3 EHRLGF'LYGHRE 5 Sheeis-Sheet 2 w, W.. W, 1W 7 M C. G. FLYGARE Filed Oct. 8, 1938 GRINDING MACHINE SWIVEL TABLE ADJUSTMENT June 3, 1941.

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June 3,1941;

- c. e. FLYGARE Q A 2,244,643

GRINDING MACHINE SWIVEL TABLE ADJUSTMENT Filed oc t. s, 1938 s Sheets-Sheet 3 'FIaS 14 1mm rm n n nu mumm CHRL GFLYGHRE- Patented June 3, 1941 GRINDING MACHINE'SWIVEL TABLE ADJUSTMENT Carl G. Flygare, Worcester, Mass, assignor to Norton Company, Worcester, Mass, a corporation of Massachusetts Application Qctober 8, @1938, Serial No. 236,912

:5 Claims.

adjusting mechanism. Another object of the in-' Vention is to provide an electric motor driven mechanism for adjusting the swivel table of a large cylindrical grinding machine of the roll grinding type. A further object of the invention is to provide a power operated swivel adjustment for a swivel table and to provide an intermediate adjusting means between the power mechanism and the pivot of the table for compensating for flexing of the table during adjustment.

A further object of the invention is to provide an electric motor driven swivel adjusting mechanism for one end of a swivel table and to provide a manual adjustment at a point midway between the power mechanism and the pivot of the table. A further object of the invention is to provide a suitable interlock between the power and manual adjustments. 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 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 plan view of a grinding machine embodying the improved swivel adjusting mechanism for the swivel table;

Fig. 2 is a cross sectional view, on anenlarged scale, taken approximately on the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary cross sectional view, on an enlarged scale, taken approximately on the line 3-3 of Fig. 1, showing the vernier scale mechanism for the intermediate swivel adjusting mechanism;

Fig. 4 is a fragmentary sectional View, on an enlarged scale, taken approximately on the line 4-4 of Fig. 1;

Fig. 5 is a horizontal sectional view, taken approximately on the line 5-5 of Fig. 4;

.Fig. 6 is an electric wiring diagram, showing the connections for operating the electric mqtor for the swivel mechanism together with the starting and interlock switches;

Fig. 7 is a fragmentary plan view, on an enlarged scale, of the Vernier scale at the end of the swivel table; and

Fig. 8 is a fragmentary plan view, on an enlarged scale, of the Vernier scale associated with the intermediate swivel adjusting mechanism.

This invention is particularly applicable to a large massive cylindrical grinding machine of the roll grinding type which may be either one of two types, namely, a work traverse type machine or a wheel traverse type machine. In either case the work piece is supported for rotation on the work sup-porting swivel table which swivels so that the work axis may be adjusted so that it is parallel to; the relative longitudinal reciprocatory movement between the grinding wheel and work to grind so that either a true cylindrical surface on the work piece may be ground or, if desired, the swivel table may be adjusted angularly so that the axisof the work is at an angle to. the relative traversing movement between the wheel and work to facilitate the grinding of tapered work pieces.

A cylindrical grinding machine of the Wheel traverse type has been illustrated in the drawings comprising a base it which supports a longitudinally reciprocable wheel carriage II on the usual V-way l2 and flat way IS. The longitudinally reciprocable grinding wheel carriage ll serves as a support for a transversely movable wheel slide it. The wheel slide it serves as a support for a rotatable wheel spindle which in turn supports on its outer end a grinding wheel It. A power driven mechanism is provided for rotating the grinding wheel 18 comprising an electric motor ll which is mounted on the upper surface of the wheel slide it. The motor ii is connected to rotate the wheel spindle l5 by means of a multiple V-belt drive l8 which is contained within a guard is supported on the wheel slide It. i

A suitable power operated grinding wheel carriage reciprocating mechanism (not shown) is provided to reciprocate the grinding wheel It longitudinally through a distance substantially equal to the work piece being ground. This mechanism has not been illustrated in the present case, since it is not considered to be part of the present invention. This mechanism may be of the type shown in the prior patent to Norton No. 1,696,188 dated May 12, 1914, to which reference may be had for details of disclosure of a wheel carriage reciprocating mechanism.

The base of a large roll grinding machine of this type is preferably made in two or more parts, one part being arranged to support the reciprocable grinding wheel carriage and the other part being arranged to serve as a support for the work piece to be ground. As illustrated in the drawings, the base ill which supports the grinding wheel carriage H has a rear base its attached thereto which supports the work supporting mechanism. In a grinding machine of this type, it is desirable to provide a swivel support for the work piece so that the axis of the work piece may be adjusted into a position parallel to the path of travel of the wheel carriage to grind a true cylindrical work piece, or may be adjusted so that the axis of the work is at an angle relative to the path of travel of the grinding wheel to produce a tapered surface on the work piece.

A swivel table 25 is provided with a lower plane surface which bears on a plane upper surface on the rear base 85a. The swivel table 25 is pivotally connected thereto by means of a pivot stud 26 (Fig. 1). The swivel table 25 serves as a support for a headstock 21 and a footstock 28 which are provided with a headstock center 29 and a footstock center 35, respectively, rotatably to support a work piece 39 therebetween.

In grinding large tapered work pieces as well a cylindrical work pieces in a machine of this type where the work piece is relatively long, it is desirable to utilize one or more steadyrests of the well known types to steady and support the periphery of the work piece during the grinding operation so as to maintain its axis of rotation in alignment with the work supporting centers 29 and 35, respectively.

In a large machine of this type where extremely long tapered work pieces are to be ground, it is necessary to swivel the table through a considerable distance to obtain the desired range of tapers. The swivel table together with the massive headstock and footstock together with the work piece weigh several tons, thus: requiring movement of a large mass to obtain the precise swivel adjustment required. A power operated mechanism is provided for swivelling the table to adjust the position of the work axis relative to the path of travel of the grinding wheel. This mechanism comprises a reversible electric motor ll] which is supported on a bracket 4! projecting from the rear of the rear base ma. The motor M! is connected through a speed reduction unit 42 which is one of the common speed reducing units comprising a worm 43 and worm gear l l meshing therewith, such as manufactured by the Boston Gear Works and others. A. shaft 45 connects the motor with the worm 43. The worm gear M is supported on a rotatable shaft 55 which is in turn connected to a rotatable shaft ll having a screw threaded portion 48 which meshes with a nut 49. The nut 49 is connected to the swivel table 25 in a manner to be hereinafter described.

The screw 48 is rotatably supported by an anti-friction bearing 50 which is supported in a frame 5!. The frame 5| is located within a transversely extending slot 52 formed in the upper surface of the base Illa. The nut 49 is slidably mounted within the frame 5| and moves longitudinally therein when the screw 49 is rotated.

The swivel table 25 is provided with a vertical stud 52 which projects below the under surface of the swivel table 25 and fits within an aperture 53 in a transversely movable slide block 54. The slide block 5t is arranged slidably to fit in a transversely arranged slideway 55 formed in the upper surface of the nut 45. This slide block construction above described serves to facilitate relative movement between the stud 52 and nut 49 when the swivel table 25 is moved to change the relationship of the work axis relative to the path of travel of the grinding wheel.

To prevent grit and water from the grinding operation from splashing or dripping onto the screw and other parts of the swivel mechanism, a telescopic guard is provided comprising the sections 58, 59 and 8%) which are arranged to telescope, one over the other, when the swivel table is moved so as to at all times protect the nut and screw mechanism.

In order to facilitate precise swivel adjustment of the swivel table 25, a vernier scale is provided adjacent to the left-hand end thereof (Fig. 1). A vernier scale 5! is fixed to a slide block 62 which slides on a scale 63 (Fig. '7). The scale 63 is fixedly mounted on the base Illa. A yokeshaped bracket 64 is fixedly mounted on the end of the swivel table 25, and is arranged to straddle a vertical stud 65 fixedly mounted on the upper surface of the slide 6 2. It will be readily apparent from the foregoing that when the swivel table 25 is adjusted, the pin 65 will move the vernier slide 6| along the scale 63 and the table 25 may be swiveled to produce the desired taper.

This swivel mechanism is particularly applicable in a large massive grinding machine capable of grinding a work piece which is forty feet or more long and one foot or more in diameter. Therefore, the swivel table 25 of necessity is a long massive piece of metal to which is attached a heavy massive motor driven headstock and footstock which are capable of supporting a work piece which may weigh several tons. Due to the size and weight of the table and the distance between the pivot point and the power driven swivel screw mechanism above described and the fact that there is considerable friction between the swivel table 25 and the base Ilia, there may be a tendency on'the part of the swivel table to flex and not to remain in a straight line when power is applied to swivel the same. To reinforce the swivel table 25 and stiffen the same, a reinforcing rib 67 is formed integral with the swivel table 25.

In order to compensate for flexing of the swivel table 25 during theswivel adjustment of the same, it is desirable to provide a suitable compensating mechanism whereby theswivel table 25 may be adjusted at a point intermediate or midway between the pivot 26 and the power driven screw it. This mechanism may comprise an auxiliary screw Til which is preferably located at a point substantially midway between the pivot 26 and the motor driven adjusting screw 44. The inner end of the screw 15 is provided with an enlarged head H having an aperture 12 which is engaged by a stud 13. The stud i3 is fixedly supported on the reinforcing rib 61 of the swivel ta ble 25. a

A substantially U-shaped bracket 14 is fixedly mounted on the rear base 15a and is provided with a clearance hole 15 through which the screw it passes. A pair of nuts 76 and 11 are screw threaded onto the adjusting screw 10 and are arranged on opposite sides of the U-shaped bracket is and serve as push and pull nuts sc -that the swivel table 25 may be adjusted at a point midway between the pivot stud 26 and the power operated screw 48 to compensate for any flexingof the table during swivellingi' v acme s In order to facilitate manual adjustment at the midway point, a Vernier l8 and a scale 19 (Figs. 3 and 8) are provided at a point adjacent to the screw iii. The Vernier scale i8 is fixed to a slide 88 which is arranged to slide along the scale B9. A bracket 8! fixedly mounted on the rib 61' of the table 25 is connected by means of a stud 82 to move the slide 88 and Vernier scale l8 when the table is swivelled. This Vernier l8 and the scale it are graduated proportionately to the vernier 6i and scale 63 so that when the swivel table 25 is adjusted so that each Vernier and scale read the same taper, the swivel table 25 will be in a straight line position to insure absolute alignment of the head and footstock centers and spindles.

An interlock is provided between the midway swivel adjusting mechanism and the motor driven swivel adjusting mechanism above described since without such an interlock, if the motor (ill were started when both of the push and pull nut 76 and El were locked in position against the opposed faces of the U-shaped bracket l -i, some of the parts of the machine would be damaged or broken. A normally closed limit switch 85 which is fastened to the rear face of the U-shaped bracket l i is provided with an actuating roller 86 which is arranged to be engaged by the nut '55. In the position of the nut W, the switch 85 is opened. A similar limit switch 87 is mounted on the inner surface of the U-shaped bracket 13. The limit switch S'lis provided with an actuating roller 88 which is arranged to be engaged by the nut 11. In the position of the nut ll (Fig. the switch 8'! is opened.

The reversible motor it is connected with a reverse magnetic starter switch 95. The starter switch 95 is arranged to rotate the motor 40 in either direction and is connected to a source of power indicated by the power lines 95 and a main control switch 9'5. To control the rotation of the motor 453, a pair of push button switches 98 and 99 are interconnected between the limit switches a? and 85 respectively and the reversible magnetic starter switch 95. The push buttons 93 and 99 are of the type which remain normally open and are closed only as long as the button is being pushed by the operator.

The switches 85 and 81 are interconnected in the electric circuit between the push button switches 98 and 99 in such a manner that when either of the limit switches 85 or 8'! are opened, the motor cannot be started to rotate the screw in one direction, thus eliminating the danger of jamming or breaking of the parts. In the position of the parts shown in Fig. 5, before any power driven swivelling of the table may be obtained, either one or both of the nuts 15 or H must be slackened off sufficiently so that the limit switch 85 or the limit switch Bl respectively closes before the motor 40 may be started.

In order to prevent the swivelling of the table in a clockwise direction (Fig. 1) to too great an extent, a limit switch 96 is mounted on the base 60a. The limit switch 9B is provided with an actuating roller 3! which is arranged in the path of the nut Tl so that if the nut H is unscrewed away from the U-shaped bracket 74 and the table 25 is swivelled by power, the nut Ti engaging the roller 9! of the limit switch 90 will open a circuit and thereby stop the rotation of the motor 49 before the nut ll jams against the rear base Illa.

The nut Hi is preferably arranged so that it cannot be unscrewed from the screw thread 10 for grinding a true cylindrical surface.

during the normal use of the mechanism. A stop collar lfill is fixedly mounted on the end of the screw it and serves to limit the adjustment of the nut It.

The operation of the improved swivelling mechanism is readily apparent from the foregoing disclosure. Assuming it is desired to adjust the swivel table 25 for grinding a predetermined ta per on the work piece 31, the nut ll is rotated on the screw l0 to withdraw th nut H from engagement with the U-shaped frame 74, thus serving to close the limit switch iii. In this position of the parts, the push button 98 may then be manually closed by the operator to start rotation of the motor &8 and the swivelling adjusting screw 48 to swivel the table 25 relative to the base Illa. This swivelling movement is continued until the Vernier 6.! and the scale 63 read the desired taper. The operator then reads the intermediate Vernier it and scale 19 to determine whether or not the table has flexed during the adjustment. By manipulation of the push and pull nuts "it and ill, the midway adjustment of the swivel table is obtained so that the Vernier i8 and scale as read the same taper as that shown on the Vernier iii and scale 63 at the end of the table. After the adjustments have been made, a clamping screw iii! is adjusted to clamp the end of the swivel table 25 rigidly in position on the base Mia. The table may be either adjusted in a manner above described so that the work axis is at an angle to the path of travel between the grinding wheel and work for grinding a tapered periphery on the work piece, or it may be swivelled so that the work axis is parallel to the path of travel between the grinding wheel and work If it is desired to swivel the table 25 in the opposite direction, this adjustment is obtained by closing the push button switch 99 which operates through the magnetic starter switch 95 to start the motor ill in the reverse direction.

As shown in Figs. 4 and 5, the nuts it and I? are clamped in adjusted position relative to the bracket it, thus opening both of the limit switches and 81, thus rendering the electric motor d8 inoperative until one or both of the nuts have been released to facilitate swivel adjustment of the table.

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 many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, 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 base, a swivel table thereon, pivotal connections between said base and one end of said table, a motor driven swivelling mechanism supported on said base and arranged to swivel the other end of said table, and an intermediate swivel table adjusting mechanism including a screw, a nut on said screw which serves to adjust the swivel table at a point substantially midway between said pivot and power swivelling mechanism whereby compensation may be made for flexing of the table during adjustment thereof.

2. In a grinding machine having a swivel table, a pivot therefor located adjacent to one end of said table, a motor driven swivelling mechanism adjacent to the other end of said table which is operatively connected to swivel said table about its pivot, an intermediate swivel mechanism including a nut and screw mechanism located between said pivot and said motor driven swivelling mechanism, and an electrical interlock between said motor driven swivel mechanism and said intermediate swivel mechanism whereby said motor is rendered inoperative except when the nut and screw mechanism is in position to allow a swivelling movement of the table.

3. In a grinding machine having a swivel table, a pivot therefor, a motor driven swivelling mechanism which is operatively connected to swivel said table about its pivot, an intermediate swivel table adjusting mechanism including a screw, a pair of nuts on said screw which serve to adjust the swivel table at a point substantially midway between said pivot and said motor driven mechanism, and an electrical interlock including a normally closed limit switch associated with each of said nuts to render said motor inoperative except when said nuts are in position to allow a swivelling movement of said table.

4. In a grinding machine having a swivel table, a pivot therefor adjacent to one end of said table, a motor driven swivel adjusting mechanism therefor located adjacent to the other end of said table, an intermediate swivelling mechanism including push and pull nuts and a screw located between said pivot and said motor driven mechanism, and an electrical interlock including a pair of normally closed limit switches each of which is actuated by one of said push and pull nuts whereby said switches are opened and said motor rendered inoperative when both of said nuts are in a locked adjusted position. 7

5. In a grinding machine having a swivel table, a pivot therefor, a motor driven swivel adjusting mechanism for said table including a reversible electric motor, a reversible magnetic starter switch to control said motor, an intermediate swivel mechanism including push and pull nuts and a screw located between said pivot and said motor driven mechanism, a pair of manually operable switches which are operatively connected to control said starter switch so as to start said motor in either direction, and an electrical interlock including a pair of normally closed limit switches each of which is actuated by one of said push and pull nuts whereby said switches are opened and said motor rendered inoperative when said nuts are in a locked adjusted position.

CARL G. FLYGARE.