US2302921A - Dressing tool - Google Patents

Description

Nov. 24, 1942. SPENCER 2,302,921

DRES S ING TOOL Filed Aug. 25, 1940 Patented Nov.- 24 1942 UNITED STATES PATENT OFFICE mig'fiiffmifilfm... Application Allg'llat 23, 1940, Serial No. 353,944

2 Claims. (01. 125-11) My I invention relates to new and useful improvements in dressing tools for grinding wheels.

An important object of my invention is to pro- .vide a tool for dressing grinding wheels that is rugged and strong inits construction and that is uniquely assembled in a manner to be readily adjustable to meet any condition that may be encountered in dressing the working face of the wheel.

Another object of my invention is to provide a dressing tool of the above-mentioned character wherein any necessary adjustments that it is necessary to make in order to adapt the tool for a particular operation maybe easily and expeditiously effected with a minimum expenditure of time and labor.

Still another object of my invention is to provide a dressing tool of the above-mentioned character that may be readily applied, as a unit, to any of the conventional grinding machines, the devicebeing uniquely formed for accommodation in the socket provided for the diamond conventionally used by the machine and thus materially increase the adjustability of the machine as well as substantially benefit the operativeness thereof.

Yet another object, of my invention is to provide a dressing tool of the above-mentioned character which, in addition to its strength and durability, is essentially simple in its construction to promote easyoperation and inexpensive :manufacture thereof.

Other objects and advantages of my invention will be apparent during the course of the following description.

In the drawing, forming a part of this specification, and wherein like numerals are employed to designate like parts throughout the same,

Figure '1 is a longitudinal sectional view, showing parts in elevation, of a device embodying my invention, I

Figure 2 is a top plan view thereof,

Figure 3 is a rear elevation of my device,

Figure 4 isa side elevation of the same, and

Figure 5- is a perspective view of a handle member adapted to be detachably connected with my device.

In the accompanying drawing, wherein for the purpose of illustration is shown a preferred embodiment of my invention, the numeral ll designates a fragmentary part of the head stock or chuck of a conventional grinding machine. The

usual construction of the part I ll includes a tubuadapted to receive the shank ll of the dressing tool or diamond nib l2. 1

My toolis adapted to be fitted to any conventional grinding machine and inasmuch as the shank II is to be fitted within the socket normally occupied by the diamond nib it is preferably of a diameter equal to the diameter of the shank II .of the nib. Any suitable provision may be made for holding the shank within the mentioned socket'of the machine, however, in order that my invention may be used to the best advantage it is desirable that some form of connection be used which will hold theshank against longitudinal displacement but which will permit the same to rotate within the socket and relative to the machine. I have here illustrated one form of connection which I have found to,

be entirely satisfactory and, in the use of this connection it is necessary that the shank be provided with an annular groove ll. passage is drilled inthe sleeve III at a point which will bring the passage and groove into register when the shank has been inserted the full distance into the socket of the machine. The passage in the sleeve is tapped anda spherical object is dropp d into the passage 'so that the lower portion thereof will fit within the groove II. A suitable clamping screw is then fitted into the passage and its inner end moved into engagement with the upper surface of the sphere. A requisite pressure may then be directed against the sphere by the clamping screw so that the 'sleeve abuts against the rear face ii of a backing plate IS. The plate connects with the shank with its transverse and longitudinal center in register with the axis of the shank, the parts being fixedly connected by the fillister head screw I1 and the locking pin I8. The front. face IQ of the backing plate is countersunk, as at 20, to seat the head of the screw flush with the inner face of the plate and the threaded shank portion of the screw extends-through the plate and into the tapped bore 2| extending axially into the shank in the manner illustrated in Figure 1. In order that the screw may be prevented from rotating within the bore 2|, I suggest that an essentially small bore be drilled at the juncture of the periphery of the screw with the side wall of the bore 2|. The pin it is then pressed into lar sleeve or a casting having an internal bore the small bore and it will thereafter eifectively A radial prevent rotation of the screw within the bore 2| and will'eilicaciously fixedly lock the'plate and shank together.

The end plates 22 are bolted or otherwise secured to the ends of the backing plate and the inner faces thereof are spaced apart a distance slightly less than the distance between the end faces of the cylindrical holder element 23. The holder is rotatably mounted between the end plates by the screws 24 which extend through the end plates and into sockets provided axially in the roller. The slightly oversized relation of the holder with respect to the end plates will cause the end plates to resiliently press against the end faces of the holder to normally hold the same in a selected adjusted position. Obviously, however, loosening of the bolts 24 will permit the holder to be rotated against the frictional engagement of the end plates.

A bore or pasasge 25 extends diametrically through the holder centrally thereof in a manner to position the axis of the bore in longitudinally spaced relation with the axis of the shank ll. Another and smaller bore 26 extends radially through the holder at right angles to the bore 25 which last bore is screw-threaded to receive a clamping screw 21. The shank I3 of the diamond nib may be fitted into the bore 25 and the clamping screw 21 thereafter rotated into engagement with the shank to hold the same against angular and longitudinal displacement.

In order that the shank ll of the tool may be easily rotated within the socket of the grinding machine I have provided a handle 28. The handle is in the nature of an elongated rod-like member which is screw-threaded at one end and one of the side edges of the backing plate is provided centrally thereof with a tapped opening 29 which is adapted to detachably receive the threaded end of the handle.

In operation, the first step of course is to lock the shank ll within the receiving socket of the grinding machine. If the working surface of the wheel to be ground is flat, the screw clamping the shank within the socket is moved to a position to securely hold the shank against both angular and longitudinal displacements. The operator then sets the diamond point 30 at the proper angle for the particular operation by loosening the bolts 24 and rotating the holder 23. Experience teaches that an angle of between 18 to 30 from the horizontal is best suited for most grinding operations. In order that the operator may quickly and accurately position the diamond nib at the proper angle, 1 have provided at least one end of the holder 23 with equi-spaced radial markings 3|. .As best illustrated in Figure 4, the extremities of the end walls are arcuately curved to aid the operator in obtaining a reading. An indicating mark 32 is made at the center of the end plate which mark is adapted to register with one of the radial lines 3| to permit the operator to readily ascertain the relative angular position or the diamond nib and to easily and expeditiously make the necesary adjustment. The chuck or head stock of the grinding machine may then be used in the conventional manner to move the diamond-across the face of the grinding wheel.

I have found that when the diamond point is disposed at the above angle, it will operate best to provide a smooth working surface on the grinding wheel. 'In order that the wheel be ground smoothly and without broken or chipped surfaces or edges, it is necessary that the diamond be maintained in an essentially sharp condition at all times. The present tool is uniquely adapted to maintain the diamond in this condition. At regular intervals the shank I! of the nib is rotated slightly within the bore or passage of the holder. A new cutting edge is thus presented to the face of the wheel after each rotation and, after the diamond has been used for a substantial period of time, it assumes an essentiallypyramidal shape, the juncture of each of the sides thereof providing a sharp cutting edge. Thus, by using the present device the diamond actually improves with age in that a longer cutting face is provided after each successive grinding operation. When the wheel is ground smoothly by a sharp point, the metal parts of the work are thrown free from the wheel which does not hold the particles of metal for the reason that the ragged edges which hold the particles are not present. Thus, the speed at which the wheel rotates keeps the wheel clean and does not permit the same to become loaded with the metal particles. The clean wheel not only re quires fewer dressings but saves substantial costs in production by giving more accurate and longer service.

If the tool is to be used for grinding a shoulder on the working face of a wheel, the clamping screw holding the shank H is backed slightly to permit the shank to be rotated within its socket. The handle 28 is preferably used for effecting rotation of the shank in the above manner. Rotation of the nib l2 to an oil center position will dispose the point 30 at right angles to the face to be worked. As the head stock or chuck is advanced toward the working face of the grinding wheel the tool may be manually rotated to position the diamond point-at right angles to the curved profile of the grinding wheel.

In order that the operator may accurately determine the angle to which the tool has been rotated relative to the holding chuck, I have provided a plurality of equi-spaced radial lines 33 on the surface I5 01. the backing plate. An indicated mark 34 on the suporting sleeve Ill cooperates with the radial lines to permit the operator to easily obtain an accurate reading. The operator may thus effectively and accurately control the position of the point and assure its proper contact with the working face of the wheel at all times.

By the nib H in longitudinal alignment with the shank ll any stresses which may be applied to the tool are equally distributed and the rugged and compact construction of the device as a unit will assure a long life and an efficient operation at all times. All of the necessary adjustments may be rapidly and expeditiously effected by the operator in a manner to expedite production and to save both time and'labor costs.

It is to be understood that the form of my invention, herewith shown and described, is to be taken as a preferred example of the same, and that various changes in the size, shape and arrangement of parts may be resorted to without departing from the scope of the appended claims.

Having thus described my invention, I claim:

1. A device of the character described comprising a backing plate, a shank detachably connected to and extending perpendicularly from the inner face of the plate, the said shank being adapted for rotary and fixed connection with a grinding machine, a handle secured to and projecting upwardly from an edge of the plate at right angles to the said shank, a pair of complementary end plates removably secured to opposite side edges of the backing plate and projecting forwardly therefrom in parallel relation, a cylindrical holder member mounted between the end plates having axial sockets in the ends thereof, a, pivot element disposed transversely on each end plate and projecting into the respective sockets for turnably supporting the holder memher, the said holder member having a bore diametrically therethrough for receiving the shank of the dressing nib, and a clamping screw threadedly mounted in the holder and engageable with the shank of a nib in the bore of the holder for releasably fastening the said shank therein.

2. A mounting for a, grinder dresser comprising a backing plate, a shank detachably connected to and extending laterally from the inner face of the plate, the said shank being adapted for rotary and fixed connection with a grinding machine chuck, a. handle forming rod secured to and projecting upwardly from the top edge of the plate at right angles to the shank, a pair of complementary end plates removably and adjustably secured to opposite side edges of the backing plate and projecting outwardly therefrom in parallel relation, a cylindrical holder member mounted between the said end plates having axial sockets in the ends thereof, a pivot forming screw mounted transversely on each end plate and projecting into the respective sockets for rotatably supporting the holder member, the said holder member having a bore diametrically therethrough for receiving the shank of a dressing nib and a radial screw threaded bore at right angles to the shank receiving bore, and a clamping screw mounted within the radial bore engageable with the nib shank for releasably securing the same in the holder.

RALPH SPENCER.

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