US1940214A - Truing device - Google Patents

Description

Dec. 19, 1933. H. w. HOLMES 'TRUING DEVICE Filed Aug. 14, 1926 35.\ H 118 @(56 4 lll 4o 75 62 70 'Ik @4 4' 4 3h92 I. 1 1%- ;9 7? y f :j

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. nr-*"1"* nl un- L 101 50 Ja 1- 9j/nj 1 1* a i l Patented Dec. 19, 1933 TRUING' DEVICE Harold W. Holmes, Detroit, Mich., maar, by

mesne assignments, to Cincinnati Grinders `Incorporated, Cincinnati, Ohio, a corporation oi.

Ohio

Application August 14, 1926. Serial No. 129,185

4 claims. (ci. 12s- 11) 'I'his invention relates to grinding machines and more particularly to devices for useI in conjunction with grinding machines for truing the surface of abrasive wheels. This application is a l continuation in part of my co-pending application Serial No. 672,844 filed November 5, 1923 for Centerless grinder.

It is the object of the present invention to provide a grinding machine arranged with a device l. which is readily accessible for accurately truing the surface of the abrasive wheel therein, and particularly suchy a device which is arranged for properly shaping the surface of the regulating wheel of a two wheel centerless grinding machine 1| from a position other than upon the line of contact between the work and the regulating wheel. Another object of the invention is to provide a mechanism for dressing or truing the surface oi an abrasive wheel which is of simple construction 20 and thoroughly practical. Another object is to provide a mechanism of this nature which is eilicient inaction and conveniently adjustable to meet the varying requirements of practical use. Other objects will be in part obvious or in part 25 pointed out hereinafter.

The invention accordingly consists in the features of construction, combinationsof elements, and arrangements of parts as will be exempliiled in the structure to be hereinafterdescribed and 340 the scope of the applicationoi which will be indicated in the following claims.

In the accompanying drawing in which Iis shown' one of 'the various possible embodiments' of this invention, 35 Fig. 1 is a sectional side elevational view or a portion of a grinding machine embodying the invention;

Fig. 2 is a front elevational view of a portion of the same; mg. a 1s a. detail pimview if` a poi-non of the same partly in section; and

Fig. 4 is an end, elevational viewy of the parts shown in Fig. 3.

In the drawing the invention is illustrated as embodied in a'two wheel centerless grinding machine comprising a base having a hollow cylindrical portion adapted to receive a cylindrical column 11 which is slidably mounted therein. A support 12 is mounted on the top of the column 11 to turn about the pivot 13 and may be secured in any desired position thereon by bolts 14 en gaging threaded holes in the column and passing through arcuate slots 15 in the support. A spindle 16 is mounted in suitable bearings li in 55 the support l2 and carries a regulating wheel 18 of any suitable'material, such as abrasive material, mounted for rotation therewith. A grinding wheel 20 is mounted upon a spindle (not shown) for rapid rotation in suitable bearings held in the frame of the machine. Suitable holding means such as members or plates and 26, for example,are provided for maintaining a work piece 27 in proper position between the grinding Wheel and the regulating wheel and, preferably, these are adjustably mounted upon the column 11. l

A water pan 30 is adjustably mounted upon a flange 31 of the column 11 by bolts 32 threaded into the pan and passing through arcuate slots 33 in the flange. The water pan 3 0 is provided with a fiat bearing surface 34 upon-which a su'pport or male slide 35 is mounted'to turn about a pivot 36 having a shoulder 37 resting against the water pan and held thereagainst by a nut 38 engaging a threaded portion o! the pivot 36. The slide 35 may be adjusted angularly about the pivot pin 36 and secured in any desired angular position by bolts 40 passing through arcuate slots 41 into threaded holes 42 in the water pan 30. The extent of adjustment of the slide 35 may be indicated by a scale 43 (Figure 2) thereupon.

By means of the bolts 32 operating in the arcuate slots 33 the water pan 30 and the complete truing-mechanismwhich is carried thereby are adjusted angularly in position with respect to the axis of the regulating wheel. When the bolts 32 are loosened and the water pan is swung for' adjustment, the truing mechanism swings therewith about the axis 13 around which the regulating wheel is pivoted and about which the latter may be adjusted to give the desired angular relation between the axis of the regulating wheel and the axis of the work, which angular relation causes the regulating wheel to feed the work along. Preferably, in ordinary operation, the water .pan is adjusted about-the pivot 13 so that i the surface 34 thereof lies in a plane which is substantially parallel to a plane passing through the axis of the regulating wheel.

A slide. 44 having suitable slideways 45 for engagement with similar slideways` 46 upon Vthe male slide 35 is provided with a cylindrical portion 47 passing through a hole 48 in the water pan. The cylindrical portion 47 of the slide is provided with a hole 49 to receive a cylindrical slide 50 keyed to move freely therein towards and from the regulating wheel and extending beyondthe cylindrical portion and carrying a cover cap 51 secured thereto by a pin 52 and overlapping one end of the cylindrical portion 47. A A dresser 110 55 on the cap 51 by a nut 56.

The slide 50 is provided with a threaded hole 60 to receive an adjusting screw 61. A cover cap 62 is mounted upon the outer end of the cylindrical portion 47 so as to rest against a shoulder 63 upon the screw 61 and is prevented from turning relative to the part 47 by a key engaging a slot 65 in the cap 62. A spring 66 surrounds the screw 61 and is adapted to engage an internal shoulder 67 upon the cylindrical portion 47 of the slide 44, the other end of the spring is arranged to engage the inner closed end of the cover cap 62. An adjusting knob 70 is provided with a slot 71 for engagement with a key 72 in the endvof the screw 61 and is held thereupon by a nut 73.,

One end of a forming bar 75 is pivoted by a pin 76 in a bracket 77 which is secured to the male slide 35 by screws 78. The other end of the forming bar 75 (Figure 3) is provided with a bearing 79 adapted to engage the inclined surface 80 of a block or wedge 81 adjustable in a bracket 82 which is secured to the male slide 35 by screws 83. The position of the block 81 Within the bracket 82 may be adjusted by turning a knob 86 resting against a shoulder 87 and engaging the threaded portion of a screwv 88 projecting from the block 81. Axial movement of the knob 86 in either direction is prevented by the provision of a U-shaped washer 89 engaging a groove 91 in the knob and secured to the bracket 82 by screws 90 (Figure 4). I

As shown in Figure 1, the cap 62 has on the underside thereof a boss 62a in which is held a downwardly projecting short shaft or spindle 62h. Upon the spindle 62h is a roller 62o which engages with the surface ofthe forming bar 75. The spring 66 urges the cap 62, and with it the members 61, 50 and the dressing tool 54, to the left, as Viewed in Figure l, or in a direction away from the surface of the regulating wheel 18. The action oi the spring 66 holds the roller or follower 62e against the surface of the forming bar 75. Thus, when the slide 44 is moved along the ways 46 of the adjustable plate 35, the roller 62 follows along the surface of the forming bar 75 and is constantly held thereagainst by the spring 66, the spring tending always to draw the dressing tool away from the wheel surface. The shape of the'forming bar 75 thus determines the path of movement of the dressing tool across the wheel surface. As shown herein, the operative sui-race of the forming bar 75 is-shown straight and hence the path of travel of the dressing tool follows a straight line. By turning the thumb wheel 86, the left-hand end of the forming bar, as viewed in Figures 2 and 3, is swung outwardly in a direction away from the regulating wheel surface, thus changing the angular position of the forming bar with respect to the regulating `wheel. Thus, by adjusting the position of the.

forming bar 75, the path of movement of the dressing tool is adjusted angularly in a plane approximately at right angles to the plane of angular adjustment effected by swinging the supporting plate 35.

The slide 44 is provided with a nut 100 integral therewith and adapted to engage a screw 101 mounted in a bearing 102 (Figure 2) upon the slide 35 and provided with a collar 103 adapted to rest against the bearing 102. A hand wheel 104 having a handle 105 is mounted upon the screw 101 so that its hub 106 rests against the other side of the bearing 102 and the hand holder 53 carrying a dresser 54 is held in a lug wheel is held upon the screw 101 by a nut 107. The screw 101 is thus held against axial movement and when it is turned by means of the hand wheel 104 the slide 44 is moved along the ways 46 and lengthwise of the angularly adjustable plate 35the follower 62e bearing against the forming bar 75 during this movement.

One end of the regulating wheel 13 is marked off into four equal segments by lines 108 positioned 90 degrees apart. When the work 27 is properly positioned between the wheels with its line oi" contact with the regulating wheel intersecting one of the lines 108, the dresser 54 preferably engages the surface of the regulating wheel at the intersection therewith of the next adjacent line 108. When it is desired to dress the regulating wheel the slide 44 is brought to the proper angular relation relative to the axis of the regulating wheel by loosening the bolts 40 and swinging the slide or plate 35 about the pivot 36 until the proper angular relation is indicatedL upon the scale 43. When the regulating wheel is inclined or tilted to effect an angle between the axis of the work and the axis of the regulating wheel, this angle should be equal to the "angle between the axis of the work 27 and the axis of the regulating wheel 18 when the dresser engages the regulating wheel on a line 90 degrees from the line of contact of the work therewith. With the dressing or truing mechanism thus adjusted, the dresser 54 is brought into contact with the surface of the regulating wheel at the point of intersection o one of the lines 108 by turning the knob 70. The slide 44 is then actuated to move the dresser 54 across the periphery of the regulating wheel by turning the hand wheel 104 to move the screw 101 within the nut 100.

With the wheel trued in this manner, the axis of the regulating wheel being at an angle to the axis of the grinding wheel and the axis of the work to exert a feeding component on the work, a concave peripheral surface is formed thereon so that, when the work 27 is properly positioned between the wheels with its axis parallel to the axis of the grinding wheel, it will contact with the surface of the regulating wheel along a straight line. Thus, the regulating wheei is provided with a surface such that it may dependably control the rotation of the work and dependably feed the work axially between the wheels.

)in order to assure that the guiding surface of the forming bar 75 is properly positioned relative to the axis of the regulating wheel, one end of the forming bar is mounted'so that it may be adjusted toward or away from the surface or axis of the regulating wheel as above described. In practice, it is preferable to true the surface of the regulating wheel so that the distance between its surface and the peripheral surface of the grinding wheel is slightly greater at that end at which the work Venters therebetween. In order` to shape the surface of the regulating wheel in this manner the bearing 79 on one end of the forming bar 75 is moved towards or away from the surface of the regulating wheel by turning the knob 86 a desired amount prior to truing the wheel.

In grinding work which is not to be fed axially through the machine, the axis of the regulating wheel n not skewed but is positioned parallel with the axis of the grinding wheel. This may be accomplished by turning the support 12 about the pivot 13 and securing it in approprif ate position by the bolts I4 and 15. So also, when it is desired to true the regulating wheel when in this position, the slide V must be adjusted so as to'permit the dresser 54 to traverse the surface `of the regulating wheel along a line parallel with the axis of the grinding wheel.

While the invention has been illustrated by reference tov a device in which the dresser travels along a line positioned 90 degrees from the line of contact between the work and the regulating lWheel, it will be readily apparent to those skilled vin the art that the dresser may travel along a line positioned at some other angular distance from the line of contact between the work and the regulating wheel. Y

Having thus described my invention,` what I claim as new and desire to secure by Letters Patent is:

1. An apparatus for truing the peripheral op` erative surface of the regulating wheel of a centerless grinding machine in which there exists an inclination between the axis of rotation of the regulating wheel and the path of travel'of the work piece being ground so that the regulating wheel exerts a feeding component upon the work, including, in combination, a dressing tool, means mounting said tool for movement across the peripheral face of said regulating wheel in a path spaced about the regulating Wheel axis substantially 904 from the line of .contact of the work with said surface, means for moving said dressing tool across the wheel surface, and means supporting said mounting means and constructed so that the angular relation between the path of travel of the dressing tool and the axis of the regulating wheel may be varied at v Will and made substantially equal to the angular relation between the axis of the regulating wheel and the path of travel of the work so that the regulating wheel surface is concaved but presents a substantially straight line of contact tol the work.

2. An apparatus for truing the peripheral operative surface of the regulating Wheel of a centerless grinding machine in which there exists anVV inclination between the axis of rotation of the regulating wheel and the path of travel of the work piece being ground so thatA the regulating wheel exerts a feeding component upon. the work,

including, in combination, a dressing tool, a carriage, means mounting said dressing tool in said carriage adapted to permit adjustment of said dressing tool toward or away from the surface of said wheel, guiding means Vfor causing said carriage to move in a straight line and to carry said dressing tool across the face of said wheel, said guiding means being positioned so that the path of travel of the dressing-tool is spaced about the periphery of the regulating wheel substantially from the line of contact of the work with the regulating wheel surface, and means for adjusting said guiding means so that the angular relation between the path of travel of the dressing tool and the axis of theregulating wheel may bevsubstantially equal to the angular relation between the axis of the work and the axis of the regulating wheel.

3. An apparatus for truing the regulating wheel of a centerless grinding machine having a grinding wheel positioned above the regulating wheel, the regulating wheel being pivotally mounted upon a support therebeneath for adjustment of its axis into angular relation with respect to the axis of the work and having mounted thereabout a water pan, comprising in combination, a plate, means mounting said plate upon the Water pan for angular achustment about an axis transversely of the wheel axis, a slide mounted on said plate, a dressing tool carried by said slide, and means for moving said slide to carry said tool across the wheel surface, a forming bar vmounted upon said plate and adjustable inposition thereon, and means on said slide for cooperating with said forming bar to control the distance radially of said tool from the axis of said wheel during movementI of said tool.

4. An apparatus for truing the operative' sur- 105 face of the peripheral regulating wheel of a; centerless grinding machine in which the regulating wheel is adjustably mounted so that the angle between its axis and the axis of the work piece being operated upon may be changed at will to vary the rate of feeding movement of the work, comprising, in combination, a dressing tool,

a carriage for supporting said dressing tool, guiding means for said carriage to guide said carriage in a substantially straight line and in a direction cross wise of the face of said regulating wheel, said guiding means being positioned so that said dressing tool on the carriage operates upon the peripheral surface of the regulating wheel at a point spaced substantially 90 from 120 the line of contact of the work with the regulating wheel, means adjustably supporting said guiding means so that the latter and the carriage may be vgiven the same angular adjustment as is given to the regulating wheel, and means for compensating for the effect of said adjustment and including means for adjusting said guiding means to cause the path offtravel of the dressing tool to make substantially the Vsame angle with the axis of the regulating wheel 's as the latter makes with the axis of the work.

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