US3007290A

US3007290A - Car wheel grinding

Info

Publication number: US3007290A
Application number: US855729A
Authority: US
Inventors: Charles H Davis; Sherwood G Scheirer
Original assignee: A P De Sanno & Son Inc
Current assignee: A P De Sanno & Son Inc
Priority date: 1959-11-27
Filing date: 1959-11-27
Publication date: 1961-11-07
Anticipated expiration: 1978-11-07

Description

Nov. 7, 1961 c. H. DAVIS ET AL 3,

I CAR WHEEL GRINDING Filed Nov. 27, 1959 2 SheetsSheet 1 ATTORNEYS Nov. 7, 1961 c. H. DAVIS ET AL 3,007,290

CAR WHEEL GRINDING 2 Sheets-Sheet 2 Filed NOV. 27, 1959 3,007,290 CAR WHEEL GRINDING (Jharles H. Davis, Ahington, and Sherwood G. ficheirer, llhoenixville, Pa, assignors to A. I. do Sanno & Son, Inc., Phoenixville, Pa, a corporation of Pennsylvania Filed Nov. 27, I959, Ser. No. 855,729 2 Claims. (til. 51-255) The present invention relates to a tool holder or chuck for reducing flange heights, adjusting the shape of fillets and removing flats from railway wheels, and to abrasive inserts therefor.

A purpose of the invention is to facilitate and accelerate the grinding of railway wheels to reduce flange heights, adjust the shape of fillets and remove flats.

A further purpose is to reduce the temperature attained by the railway wheel during grinding.

A further purpose is to permit the insertion of a chuck in place of the brake shoe in a conventional railway brake, to mount one or preferably a pair of preformed abrasive blocks in clamps in the chuck, and to grind the wheel by moving the railway car or other vehicle along the track.

A further purpose is to provide preformed abrasive inserts in the chuck which have tapered surfaces for grinding the wheel tread and if desirable, associated recesses for grinding the flange, so as to prevent producing a disproportionate flange. The invention is also applicable to modifying the shape of the curvature or fillet between the flange and the tread.

A further purpose is to provide in the chuck a segmental or chord portion for the reception of the part of the abrasive block or insert which grinds the tread and also a channel if desirable for reception of the portion of the abrasive block or insert which grinds the flange.

A further purpose is to locate a pair of abrasive blocks or inserts in the chuck at circumferentially spaced positions preferably interposed by an abutment against which the blocks or inserts are clamped.

A further purpose is to provide on the chuck an car which is similar to the ear on the usual brake shoe and to engage the ear in the brake head by the usual pin.

Further purposes appear in the specification and in the claims.

In the drawings we have chosen to illustrate a few only of the numerous embodiments in which the invention may appear, selecting the forms shown from the standpoints of convenience in illustration, satisfactory operation and clear demonstration of the principles involved.

FIGURE 1 is a diagrammatic fragmentary side elevation of a wheel, brake and chuck assembly according to the invention.

FIGURE 2 is an elevation of the chuck looking radially toward the center of the wheel.

FIGURE 3 is a side elevation of the chuck.

FIGURE 4 is a fragmentary end elevation of the chuck.

FIGURE 5 is a section of the chuck on the line 5--5 of FIGURE 2.

FIGURE 6 is a view similar to FIGURE 5 showing a modification of the shape of the insert.

In the prior art, considerable difficulty has been encountered due to flatness in the rim or tread of railway wheels of cars and other railway vehicles, and also due to malformation of the flange, especially excessive height of the flange which makes it tend to climb the rail and derail on curves and switches, and also due to combinations of the above conditions.

A widely used practice has been to substitute for the brake shoe a series of heavy metal cups, one for grinding the tread, one for grinding the flange, and one for rates Patent grinding the curved contour or fillet between the tread and the flange of the car wheel. Into these cups is deposited loose abrasive particles which are bonded by sodium silicate. The proper cup containing the abrasive particles has been placed on the car instead of the brake shoe and the car run up and down along the track while the brakes were applied. The abrasive grinds either the tread, the flange, or the curved contour between the tread and the flange of the wheel. Excessive heat has developed and the peripheral surface of the car wheel has been so much heated that the surface frequently becomes burned and heat checks develop, but it has not been possible to use water cooling because the sodium silicate is water soluble.

After a short period of use the abrasive-containing cups have required replacement.

The present invention is designed to provide an abrasive insert and a chuck which will precisely machine the tread and the flange of the wheel to the desired contour.

Water cooling can be used. The use of water or other coolant is optional, but not necessary. Excellent results are obtained by grinding dry.

The present inserts or segmental blocks are preformed, and new inserts can readily be placed in the chuck. These inserts can be made of any suitable type of abrasive including aluminum oxide or silicon carbide and bonded with any of the conventional methods of bonding including vitrified, resin, shellac, rubber or silicate.

The weight and bulk of the chuck is greatly reduced since it is no longer necessary for the chuck to function as a mold for the abrasive.

Grinding may occur at higher speeds where cooling is used due to the more resistant character of the abrasive.

The changing of the chuck or of the insert in the chuck can be accomplished very quickly.

Due to the ready replacement of the segments, the cost of the grinding material is reduced to as little as onethird. The same chuck can hold inserts of different contours as desired.

It is no longer necessary according to the invention to return the chuck to an abrasive manufacturer for refilling.

The abrasive blocks or inserts may cover a portion or the entire outer contour of the wheel as desired although they will preferably conform to the contour of both the tread and the flange, and the curved area or fillet between the tread and the flange.

Considering now the structure shown in the drawing, we there illustrate a railway wheel suitably a car wheel, 20 mounted on an axle 21 and having a tread 22, a flange 23 and having a fillet 23' between the tread and the flange, as well known.

The railway truck is provided wtih the usual b ake mechanism, including truck levers 24 and 25, one in front of and one behind the wheel, pivoted at 26 (only one pivot is shown) and operating in the manner well known in the art to urge opposed brake heads 27 pivoted to the truck levers at 28 toward the outside of the wheel. At the truck lever 25 the brake head is pivotally mounted by a link 30 pivoted to the truck lever at 31 and pivoted to the brake head at 28, while at the truck lever 24 the brake head is directly pivoted on the truck lever 28.

A connection strap 32 is pivotally connected at the lower end of each truck lever and is provided with a slack adjuster 33, all of which are well known in the art.

In normal operation each brake head carries a brake shoe 34 which is held to the brake head by extending a T-shaped pin 35 through an opening in a lug 37 of the character later described and through openings in the head, all as well known in the art.

In accordance with the invention, one or both of the brake shoes is removed from its brake head and an abrasive holding chuck 36, as best seen in FIGURES 2 to 5,

is substituted. The contour of the outside of the chuck is identical with the contour of the ordinary brake shoe, including an arcuate or segmental portion 37 opposite the tread, a central radially extending lug 37 having a pin opening 38 which receives the pin 35 already described, and end abutments 40 in line with the hole 38 through the lug, as well known in the art, which engage the ends of the pin 35.

Unlike the brake shoe, however, the inside of the chuck is especially formed and the chuck has a portion extending around the flange of the wheel which is especially formed. At the interior in the middle opposite the lug there is a trapezoidal clamp abutment 41, and beyond the clamp abutment in both circumferential directions there is a chord 42 which engages the radial outside edge 43 in a preformed abrasive block or insert 44 which has an arcuate and axially tapered inner portion 45, best seen in FIGURE 5.

At the portion of the chuck adjoining the flange of the wheel, there is a chord-like channel 46 which receives a flange engaging portion of the abrasive block or insert which has an interior arcuate and recessed portion 47, best seen in FIGURE 5, and conforming to the flange contour. There is a merging curve at 47' between the arcuate interior and the flange groove.

At the opposite circumferential ends of the chuck there are abutments 48 through which clamp screws 50 are threaded to urge the ends of the abrasive blocks or inserts against the central abutment -41. Each clamp screw has an annularly flanged head 51 which mounts rotatably thereon a pressure head 52 which has an annular slot to receive the flange 51 on the screw.

FIGURE 6 shows an embodiment which is similar to FIGURE 5, except that the insert 44' engages only the portion of the wheel corresponding to the tread and the merging part of the fillet, and does not grind the flange.

In operation the abrasive blocks are inserted in the chuck and the chuck is placed on the car instead of one or both brake shoes. The brakes are then set and the car is moved up and down the track until the flat or other imperfection in the wheel has been removed.

The chuck or chucks are then removed and brake shoes applied to replace them, and the car is ready for service.

It will be evident that the invention can be employed to perform any one of the following functions independently, or two or more of these functions cooperatively:

(1 Truing the tread of the car wheel.

(2) Reducing the height of the flange to accepted tolerance.

(3) Returning the fillet or curved area between the tread and the flange to proper contour.

It will further be evident that one of the great advantages of the invention is that even with dry grinding, the heat developed has been reduced so markedly that the chuck and the abrasive blocks can be removed immediately from the car wheel once the operation is finished, without danger to personnel. This represents a marked saving in time.

It will further be evident that the abrasive blocks, by the reduction in temperature which is made possible, eliminate the danger of burning the wheel or producing heat checks or minute cracks in the wheel surface.

It will further be evident that the reduction in weight made possible by the present invention simplifies the problem of applying and removing the chuck.

It will further be evident that the cost of the grinding equipment and the over-all cost of the grinding operation are reduced by the present invention.

In view of our invention and disclosure, variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to obtain all or part of the benefits of our invention without copying the structure shown, and we, therefore, claim all such insofar as they fall within the reasonable spirit and scope of our claims.

Having thus described our invention what we claim as new and desire to secure by Letters Patent is:

1. A railway wheel machining device comprising a railway wheel and brake assembly including a railway wheel, a brake cooperating with the wheel including a railway brake head pivotally connected at a center position on the head to the brake mechanism and brake operating mechanism for moving said railway brake head toward the outer circumference of the wheel, in combination with a chuck secured in the brake head, having at the side remote from the wheel a centrally located lug interconnected with the brake head, having a chord portion adapted to receive an abrasive insert for grinding the wheel rim, and having a recessed portion adjoining the chord portion and adapted to receive an abrasive insert for grinding the wheel flange and having clamp means for securing an insert in said chuck, in combination with a preformed abrasive block in the chuck engaging the chord portion and also engaging the recessed portion of said chuck and gripped by said clamp means.

2. A machining device of claim 1, in which said chuck has a plurality of circumferentially disposed chord portions and adjoining recessed portions, an abutment be tween said cireumferentially disposed chord portions and recessed portions, a preformed abrasive block in each chord portion and recessed portion, and opposed clamping means engaging each said abrasive block and urging the same against said abutment, there being a discontinuity in the grinding face of said abrasive blocks between said blocks.

References Cited in the file of this patent UNITED STATES PATENTS 750,479 McCormick Jan. 26, 1904 1,221,211 Demberton Apr. 3, 1917 1,510,181 McClure Sept. 30, 1924 1,672,462 Mansell June 5, 1928 1,742,070 Groves Dec. 31, 1929 2,304,847 Piron Dec. 15, 1942 2,664,679 Kelley Jan. 5, 1954