US2170304A - Truing attachment - Google Patents

Description

-Aug. 22, 1939. c. HERFURTH mums ATTACHMENT Filed Dec. 6, 1937 6 Sheets-Sheet 1 BIC O 1 fl- 1939- c. HERFURTH TRUING ATTACHMENT 6 Sheets-Sheet 2 Filed Dec. 6, 1937 INVENIOR. C HA ELES HER'FUR TH WW.

ATTORNEY.

Aug. 22, 1939. Q mH 2,170,304

' TRUING ATTACHMENT jsFiled Dec. 6, 1.937 14 6 Sheets-Sheet 4 AI/I. v ////V" INVENTOR. CHARLES HERFURTH BY WWW ATTORNEY.

Aug. 22, 1939. v c. HERFURTH 2,170,304

I mums ATTACHMENT I Filed Dec. 6: 1937 6 Sheets-Sheet 5 v INVENTOR.

6 HA IZLES HERFl/l? TH I ATTO EY.

0 t n\\ Or m fiw fi .mw 7 1 1 9 w NE 2 w H. a 6 M H Cr H w Tn Run um w Y FM B m GD Hm v GEM N am Aug. 22, 1939.

ATTORNEY.

Patented Aug. 22, 1939 TRUING ATTACHMENT Charles Heriurth, Cincinnati, Ohio, assignor to Cincinnati Grinders Incorporated, Cincinnati. Ohio, a corporation of Ohio Application December 6, 1937, Serial No. 178,225

3 Claims.

This invention relates to grinding machines and more particularly to improvements in truing attachments therefor.

One of the objects of this invention is to provide an improved compact truing attachment for grinding machines.

Another object of this invention is to provide an improved operating and control mechanism for a truing attachment which is self-contained in the attachment.

A further object of this invention is to provide a simplified'power operable control mechanism for a truing attachment which-will execute one stroke at the will of the operator.

- An additional object of this invention is to provide an improved truing attachment which is angularly adjustable for producing straight beveled surfaces on the wheel, or which may be contour controlled for producing other than straight surfaces on the wheel.

Other objects and advantages of the present invention should be readily apparent by reference to the following specification considered in conjunction with the accompanying drawings illustrative of one embodiment thereof, but it will be understood that any modifications may be made" thereof.

Figure 3 is a section through the mechanism as viewed on the line 3-3-0! Figure 2.

Figure 4 is a section through the control valve mechanism as viewed on the line 4-4 of Figure 2.

Figure 5 is a section on the line 5-5 of Figure 2.

Figure 6 is a section on the line 6-6 of Figure 2.

Figure '7 is a section on the line 1-1 of Figure 2.

Figure 8 is a section on the line 8-8 of Figure 2..

Figure 9 is a section on the line 3-! of Figure 2.

Figure 10 is an elevational view of the contour control mechanism as viewed on the line il lfl of Figure 1.

Figure 11 -8. of Figure 10.

detail section on the line u Figure 12 is a diagrammatic view of the hydraulic control circuit.

Figure 13 is a section on the line I3l3 of Figure 5. I

Figure 14 is a section on the line ll of 5 Figure 5.

Referring to Figure 1 of the drawings, the reference numeral Iii indicates a fixed part of a machine tool, having a guide surface ll, upon which is adjustably mounted a bracket l2. A 10 pair of T-bolts i3, mounted in a T-slot it formed in the support II, and passing through "the bracket l2, serve to secure the bracket'to the fixed part ill of the'machine. By means of this arrangement, the bracket may be adjusted to- 5 wards and from the axis i5 of a grinding wheel IS.

The bracket is provided with a top supporting surface l'l upon which is mounted a saddle ii. i As shown in Figure 3, a pivot pin is is fixed in the bracket i2 and projectsinto a hole formed 20 in the under side of the saddle to serve as a pivot point about which the saddle may be moved for changing the angular relation of the guide surfaces 2! formed on the top side of the saddle with respect to the axis i5 of the grinding 2 wheel. Clamping screws 22 passing through elongated slots 23, in the saddle and threaded in the bracket i2 serve to clamp the saddle in different angular positions. As shown in Figure 2, graduation marks 24 are formed on the rear of the bracket i2 for cooperation with a zero mark 25 formed on the saddle to indicate the amount of angular adjustment.

it slide 26, having guide surfaces 21 shaped to cooperate with the guideways 2|, is mounted z on the saddle for relative sliding movement in l a rectilinear path. The slide 26 has a bore 28 formed therein for receiving a tubular member.

29 which carries the truing'tooljll. The tubular member 29 is adapted to slide crosswise relative to the slide 26 and to this endls normally urged in one direction by a spring 3i which is interposed between a lug 32, integral with the tubular member, and a lug 33 integral with the slide 26.

To control this movement the slide 26 has a de- 5 pending bracket 3, in which is rotatably mounted a roller 35 cooperating with an adjustable cam bar 36 carried by the saddle it. The spring Sl continuously maintains the roller 35 5 l in contact with the cam bar. As shown in Figure 11, the cam bar 35 is held in place by a pair of clamping members 31, which have radially extending lugs 38 which overlapreduced portionson the ends of the cam bar. Clamping screws 3! pass through the clamping members and are '55 threaded in a longitudinally adjustable cam bar carrier 40. l

The cam bar is made flexible so that it may be adjusted to impart difierent degrees of curvature or camber to the face of the grinding Wheel. This adjustment is efiected by a bolt 4| which is threaded in the carrier 40 about midway between the ends of the cam bar and so that the head oi the bolt will engage the cam bar and deflect or bend the same. A recess 42 is formed in the carrier 40 around the head of the bolt 4| to permit insertion of a suitable tool for rotating the nut.

Since different widths of grinding wheels may be applied to the spindle within certain limits, and since it is usually desirable that the high point of a camber should be in the center of the grinding wheel, the carrier 40 is adjustable so that the axis of the bolt 4| will lie in a plane passing through the central plane of the grinding wheel regardless of its width. This adjustment is accomplished by providing elongated slots 43 in each end of the carrier through which clamping bolts 44 threaded in the saddle l8 will pass, so that when these bolts are loosened, the carrier may be adjusted longitudinally. To facilitate large adjustments additional threaded holes 45 may be provided in the saddle 18 for receiving thebolts 44. To assist the operator in making these adjustments, the carrier 40 is provided with a depending pointer 46, which cooperates with a suitably marked scale 41 attached to the saddle l8, as shown in Figure 10. It.will now be evident that when the camber determining screw 4| is adjusted out of engagement with the cam bar 36, that the same will be straight, and that the diamond tool will travel a rectilinear path; and that when the screw is adjusted to flex the camber bar 36, that the tool will travel a curved path, the spring 3| always holding the follower 35 against the cam bar.

Power operable means have been provided for reciprocating the slide 26 relative to the saddle Hi. This power operable means is hydraulic in nature, and the actuating and control means are very compactly arranged in the saddle. This compact arrangement is obtained by providing a longitudinal bore 48 in the saddle substantially midway between its top and bottom surfaces and extending longitudinally through the same in parallel relation to the guide surfaces formed thereon. This bore is divided into a cylinder por-- tion and a valve portion. Within the cylinder portion is a piston 49 which is connected by a piston rod 58 to a bracket depending from the slide 26. Cylinder head 52 is fitted in one end of the bore 48 for closing the same and for supporting the piston rod 58 which passes through it.

A valve housing 53 having a solid end 54 is inserted in the other end of the bore 48, and serves as a closure for that end of the bore in order to form a closed cylinder for operation of the piston 49.

The valve housing includes a tubular member 55 which fits tightly in the bore 48 and has a series of annular grooves 56, 51, 58, 59 and 69 formed in its periphery. A generally cylindrical valve member 6| is rotatably mounted within the sleeve and this valve member has portions cut away midway of its length to form two intersecting vanes 62 and 63 which divide the valve into four quadrants 64, 65, B6 and 61. The groove 58 is connected by an interdrilled passage 58, as shown in Figures 6 and 14, to an external pressure supply pipe 69. As diagrammatically shown in Figure 12, this pipe may be supplied with fluid pressure from a suitably located pump lllhaving an intake H through which fluid is withdrawn from a reservoir 12.

Referring to Figure 7, the annular groove 59 is connected by an interdrilled passage 13 to port 14 located in the right hand end of the cylinder portion. The, annular groove 50, shown in Figure 8, is connected by an interdrilled passage 15, which is more particularly shown in Figure 13, to port 16 located in the left hand end of the cylinder portion.

The vanes of the valve are normally held in the position in which they are shown in Figures 5, 6, 7 and 8 by a detent mechanism which is more particularly shown in Figure 9. The plunger is provided with a reduced operating stem H which extends through the head 18 and provided with an operating handle 19. Between the head 18 and the enlarged portion of the plunger is keyed a detent plate 89 which has Vshaped notches 8| formed in opposite sides of its periphery. A pair of spring pressed detent plungers 82 are slidably mounted in sleeves 83 which are inserted in opposite sides of the saddle l8 and secured in place by screws 84. The detent plate is keyed to the shaft 11 in the proper angular relation so that when the detent plungers engage the bottom of the V's, as shown in Figure 9, the vanes of the plunger are in the position shown in Figures 5, 6, 'l and 8.

To limit rotation of the valve plunger, a limiting groove 85 is cut in the top of the detent plate and a stop screw' 86 is threaded in the sleeve 55 with a reduced portion projecting into the groove whereby after a predetermined angle of rotation of the valve, the reduced portion will contact one end or the other of the groove.

The pressure groove 58, shown in Figure 6, has a pair of diametrically opposed radial ports 8'! which, it will be noted, lie in a vertical plane and in alignment with opposite ends of the vane 62. The annular groove 59, shown in Figure '7, has a pair of opposed radial ports 89 which lie in a plane substantially 45 out of phase with the plane of the ports shown in Figure 6 and in a clockwise direction. The annular groove 68 shown in Figure 8 has a pair of opposed ports 98 lying substantially 45 out of phase with the pane of the ports shown in Figure 6 but in a counterclockwise direction. It will now be apparent that if the valve is rotated in a clockwise direction, as viewed in Figures 6, 7 and 8, that the pressure ports 87 will be connected through quadrantgrooves 65 and 5l.to port 99 whereby fluid pressure will flow through port 76 to the cylinder; and if the valve is rotated in a counterclockwise direction, the ports 81 will be connected by quadrant grooves 64 and 66 to ports 89 whereby pressure fluid will flow to port I4 of the cylinder.

Additionally, when the valve is rotated clockwise, the quadrant grooves 64 and 66 will connect the ports 90 to a pair of diametrically opposed ports 9| which, as shown in Figure 5, communicate with annular groove 51; and when the valve is rotated counterclockwise, the quadrant grooves 65 and 6! will connect the diametrically opposed ports 90 leading from the right hand end of the cylinder to ports 9| and thereby to annular groove 51.

As shown in Figure 5, the annular groove 51 is connected by a passage 92 to an adjustable throttle valve indicated generally by the reference numeral 93. It will be noted that this throttle valve extends at right angles to the axis thereto, and that the passage 92 is coincident with radial lines of the bore 48 and the valve.

The throttle valve plunger 94 is provided with a spool 95 which is adjustable'relative to the end of passage 92 and in the end of the spool is a. V-shaped notch 96 which, as it is adjusted toward the left as viewed in Figure 5,'increases the opening to annular groove 91 formed in the throttle valve plunger and as it is adjusted toward the right, decreases the opening to the annular groove. In other words, this groove serves to regulate the rate offlow from the exhaust end of the cylinder and thereby regulate the rate of movement of the truing tool across the face of the grinding wheel. The annular groove 91 is in constant communication with a port 98 which is connected by an interdrilled passage 99 to an external exhaust pipe I00, as more particularly shown in Figure 14. This exhaust line may have a check valve l| suitably placed therein for maintaining a small back pressure in the connecting lines and thereby maintaining the system full of fluid.

The throttle valve plunger is shown in its greatest feed rate position in Figure 5, and as it is moved toward the right in that figure, it reduces the feed rate of the truing tool. This adjustment is effected by providing a threaded portion I02 on the plunger which interengages with threads I03 formed-in the end of the valve and rotating the same by means of a knurled operating knob I04. The operating knob I04 has a skirt portion I05 movable relative to a barrel portion I06 integral with -the end of the valve, and by providing suitable graduations on each, the rate of movement of the slide may be calibrated. A

spring I01 is interposed between the end of the valve and the end of the knob for removing any back lash between the screw I02 and the threads I03. It should now be evident that if the operator throws the lever I9 in either direction from its normal central position and holds it there against the action of the spring pressed detents, that the truing tool will be moved across the face of the grinding wheel at a rate determined by the setting of the throttle valve, and when he releases the handle the valve will return to a central position which will stop this movement. The direction of movement, of course, will be determined by the-direction in which the operator moves the handle I9 from its central position.

In order to prevent excessive pressure building up in the valve when the slide is not being used, the vane 62 is provided with a diametrical passage I08 which intersects a cross bore I09 that terminates in a second diametrical bore IIO. This bore terminates in the periphery of a spool I which lies opposite a pair of diametrical ports II2, as more particularly shown in Figure 4, which are in communication with an annular groove 56. The groove 56 is connected by an interdrilled passage H3 to the interdrilled passage 99, as more particularly shown in Figure 14 Thus the H-shaped passage formed in the interior of the valve plunger serves to connect the pump "to reservoir, audit will be noted in such a manner that the valve plunger is always under hydraulic balance due to the pairs of diametrically opposed ports.

There has thus been provided an improved compact truing mechanism which is designed to be built'as a self-contained unit including the necessary means for power reciprocating the truing tool, the necessary control means for determining the rate and direction of said movement and various adjustable means for determining the shape of the contour to be imparted to the wheel and regardless of variations in'the width of the face thereof.

What is claimed is:

1. In a truing attachment for a rotatable grinding wheel of a grinding machine, the com bination of a support having a guideway lying in a radial plane with respect to the axis of the grinding wheel, a bracket mounted on said guideway for adjustment in said radial plane, a truing tool carrier, means mounted on the bracket for supporting said carrier for axial movement in for power shifting said slide and carrier.

2. In a truing attachment for the grinding wheel of a grinding machine, the combination of a bracket having top and bottom surfaces which lie in planes that intersect, a saddle pivotally mounted on said top surface, guideways formed on the top surface of the saddle and-receiving a slide, and a truing tool carrier supported on the slide for axial adjustment transversely of the direction of slide movement, the carrier adjustment axis intersecting the plane of the bottom surface of said bracket in the axis of the grinding wheel whereby said attachment may be mounted on a surface of the machine which lies in a radial plane with respect to the axis of the grinding wheel and still position the axis of reciprocation of the truing tool in a second radial plane with respect to the axis of the grinding wheel.

3. In a truing attachment for a grinding machine, the combination of a Supp rting bracket, a truing tool carrying slide, a saddle interposed between the top surface of said bracket and said slide, said saddle having parallel top and bottom surfaces, one of which includes guideway means for said slide, a pivotal connection between the bottom surface of saidsaddleand the top surface of said bracket for angularly varying the path of reciprocation of said slide, said saddle having a bore passing tlnrough the same midway between the top and bottom surfaces thereof, means dividing said bore into a hydraulic cylinder and a valve housing, a piston reciprccably mounted in the cylinder and operatively connected to the slide, a valve mounted in said housing, interdrilled passages formed .in said saddle connecting said valve respectively .to opposite ends of the cylinder, to exhaust, and to a source of pressure, detent means normally positioning said valve to isolate the interdrilled passages leading to opposite ends of the cylinder and simultaneously to connect the pressure supplying passage with the exhaust passage, whereby the slide will remain at rest and manually operable means for moving said valve to effect hydraulic operation of said slide.

CHARLES HERFUR'I'H.

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