USRE20466E

USRE20466E - Abrasive cutting machine

Info

Publication number: USRE20466E
Authority: US
Publication date: 1937-08-10

Description

Aug. 10, 1937. D. LEWIS El AL 20,465

ABRASIVB CUTTING MACHINE Original iiied April- 18, 1934 2 Sheets-Sheet 1 INVENTORS DARrREY LEW/6 Warn/0 L. WALM. BY WALTER a. LAMAR")?! ATTORNEY 4 Aug. 10, 1937. o. LEWIS El AL 20,466

ABnAsivs cum-ms MACHINE Origipal Filed April 18, 1934 2 Sheqts-Sheet 2 INVENTORS .DARTREY LEW/.5, W/LFRID L. wALsH, BY WALTER B.LA.smR,-m

Rea Au 10, 1937 UNITED STATE aaaasrvn co'r'rmo Dal-trey Lewia'Boston, and Wilfrid 1.. Walsh,

Cambridge, Mass,

and Walter B. Lashar, Jr.,

Failfield, Conn, assignors to American Chain '& Cable Company, 1m, Bridgeport, Conn, a corporation of New York Original No.

2,031,052, dated February 18, 1930,

Serial No. 721,128, April 18,1934. Application,

for reissue December 14,

9 Claims.

This invention relates to animproved method and apparatus for cutting various substances, more particularly those of a brittle nature, although it is usefully applied, to the cutting of any hard substance whetheror not having the :haracteri'stic.of brittleness, such. as various steels and other metals, plastic compositions, hard rubber, etc, The invention involves, as its principal, feature, the cutting of such materials 10 while they are subject to the action of a stream of water or other suitable liquid as distinguished from other processes recently developed wherein they are submerged in a body of water. We are aware of the fact that it has already-been found that, when cutting metals with a thin abrasive wheel, it is of great advantage to submerge'the -material .in a liquid-more commonly waterthe result of which is a smooth, clean cut with a substantially perfectly plane section. without burrs on its edges and without any deleterious effects from burning or undue heating. We have found that, while submergence of the materials during cutting with wheels of the type abovementioned is highly advantageous, there a are many cases in which complete submergence or immersion can be dispensed with and a stream of water directed on the work in the region of cutting, provided such stream of water be of suitable volume and be properly directed and con- I With the foregoing and other objects in view,

the invention consists in a certain method and improved means for carrying out the method, as will be more clearly disclosed in connection with the accompanying drawings, but it is to be understood that we are not limited to' the specific apparatus shown, it being quite feasible to carry out the method in various other apparatus.

Referring'to the drawings,

Fig. 1' is an elevation of the machine partly in section; r

Fig. 2 is a view'on the line 2-2 of. Fig. 1; and Fig. 3 is a plan view on the line 3-3 of Fig. 1.

These drawings show the embodiment of the 45 invention in a machine which has proven very efficient in carrying out the process referred to. It comprises a bed III which may be provided with vertical peripheral walls II to form a reservoir or container for water or other liquid em- 50 ployed in the cutting operation, as will be hereinafter more particularly pointed out. This bed or container maybe mounted on any suitable support such as the pedestal ll. The container may be provided with rearwardly extending 55 brackets IS on which may be pivotally mounted,

1936, Serial No. 115,888

as by a shaft 15, a frame ll carrying the thin abrasive cutting wheel indicated atjll and the power means for driving this wheel, such as an electric motor It. In theprcsent instance, the wheel is removably mounted on a shaft 20 running in bearings 2| in the frame, I! and is driven by a suitable flexible drive such as a V-belt drive .22 running over pulley 23 on the shaft 20 and also on a drive pulley (not shown) carried by the motor shaft in theusual manner. It is' also preferred to provide means for adjusting the tightness of this belt drive, and, in the present instance, the motor is carried on a frame 25 secured tofan upright bracket 26 pivoted in the frame I'l at ll between arms 28. This bracket 26 also has a lug 29 provided with an arcuate slot ill struck with the pivot 21 as its center. ,An adjustable clamping bolt 3| carried by the lug 32 on the frame ll provides a means for bolding the bracket 26 in adjusted position.

. It will be noted that the wheel II with its mounting means and the motor I9 are mounted on opposite sides of the pivot Ii of the frame I1, and therefore these elements counterbalance each other so that, in swinging the frame to move the wheel to and from the work, very little effort is required. Preferably the motor should overbalance the wheel somewhat so as to retain the wheel in the upright position-that is, away from the .work between cutting operations. An adjustable limit stop is carried by the frame H to limit downward movement of the wheel to prevent its being shifted further, than necessary for severing the particular section being out. In the construction shown, this comprises a rod 33 threaded into 9, lug 34 on the frame and having a crank handle 35 whereby it may be adjusted. At its lower end it is adapted to engage an upwardly; extending. stop wall "carried by the container Hi to limit downward movement of the wheel. The frame Il may to shift the wheel to and from the work by any suitable handle Ila adjustably secured to the frame at l'lb.

The wheel is preferably enclosed in a suitable safety guard so that, should it break, there will be no flying pieces to injure the operator. This guard is illustrated as a sheet metal member 42 extending over and enclosing the wheel and including an enclosing wall 43 on one side. On its opposite side it has an opening ll of sumcient diameter to permit insertion and removal of the wheel for application driving shaft 20. After this opening is closed by the wheel is applied, a coverplate l5, prefbe rocked on its pivot to and removal from the erably detachably secured in position by any suitable means. The rear wall 3 is provided with an arcuate slot 41 through which the shaft 20 extends and permits up and down movement of the wheel. The guard may be mounted by any suitable means.

As the wheel I8 during the cutting operation rotates, it will be evident that it tends to carry any liquid that it may pick up into the guard. To prevent this a stripper plate 48 is provided, this stripper plate extending laterally on opposite sides of the rear portion of the wheel. This plate may be mounted on the guard as indicated at 49 and may comprise a single plate '48 with a narrow slot which affords just suflicient clearance to permit the wheel to rotate. This plate efiectively strips from the wheel any liquid that may be carried upwardly with it. Of course, the material to be cut must be held in the proper position in the container. Satisfactory means for doing this may comprise the supporting blocks 52 and 53 separated by a narrow space to permit the abrasive wheel ii to pass between them. These blocks have properly shaped notches 55 to receive the work, which, in the drawings'indicated, consists of a tube l3. These notches may be of various shapes, but they are preferably tapered so that the work is firmly held. Of

course, certain sections would be more stable in other shapes than V-notche's, and, consequently, for particular Jobs the shape oi the notches would be adapted accordingly. Manually oper-- ated means are also provided for clamping or holding the work in these supporting blocks. In the present instance this clamping means comprises a lever 56 pivoted at 51 to lugs 58 on the forward wall of the container l0, and this lever includes a pair

ofspaced arms

59 and 60 extending at their free ends over the blocks 52 and 53. They are spaced sufliciently to permit the wheel IE to pass between them, and these arms, with the blocks 52 and 53, provide means for clamping and holding the work on both sides of the wheel. The handle GI permits lifting of the arms 59 and .60 to release the work and also to control the movement of the arms 59 and to the work holding position; It has been found advisable, however, when certain materials and shapes are being cut, to provide yielding resilient means for holding these clamps against the work. Thus the lever 56 is provided with an arm 62 carrying adjustable screw 63 threaded in the arm and engaging the end of a 'slidable block 64 mounted in a recess in the container III. In this recess isa spring 65 which tends to force the block 64 out against the screw 63 and to clamp the

arms

59 and 60 down on the work. After adjustment,

the screw 63 may be locked in adjusted posi-.

tion by lock-nut 6B, and itwill be evident that, with this construction, the tension of the spring may be adjusted, and, as a consequence, the pressure of the clamp on the work.

It has been found that in cutting glass tubes and particularly thin wall glass tubes, they should not be clamped too firmly. This adjustment of the pressure of the spring 65 is very effective in securing a proper yielding resilient press re. It also seems advisable to have yielding Jesilient pads to contact with the work especially when glass tubes are being cut, and we further use such pads 61 preferably of live rubber or similar material. v

To the container Ill there is also aflixed a block 68 provided with a passage 69 having a curvature slightly greater than that of the wheel a d loca ed with its center of curvature approximately in the axis of rotation of the wheel at the average position of the latter when cutting through a section-thatis to say, the center of curvature of the conduit wouldordinarily be in the axis of rotation of the wheel when the latter had about half out through the average section that the machine is designed to operate upon. The walls of the passage 59, it will be noted, are partially composed of the flanges I0 on either side of the wheel, these flanges extending toward each other to a waste pipe or circulated by a pump for repeated use, if desired.

In using the machine, the materialwhich for purposes of illustration may consist of the glass tube l3is laid in the V-shaped notches of the blocks 52 and 53 and clamped therein by bringing the padsS-I down upon it. With'the wheel rotating in a counterclockwise direction, as viewed in Fig. l-that is, in a direction to carry down the conduit water led in through the pipe H, the wheel is brought down by manipulating the handle "a and the desired cut made. It is important that the conduit 69 be so constructed .that the stream of water emerging from it shall impinge on an area which includes the point of entrance of the wheel into the cut, this region being sufliciently large to always include that point as the cutting progresses. Of course, it is obvious that for several reasons it is desirable that the wheel run in a fixed plane in order that lengths of uniform thickness may be cut from rods, bars, sheets, and the like, and, furthermore, to avoid breakage. I It is therefore important that the cross-section area of the conduit be symmetrically designed with respect to the plane of the wheel so that the pressure on both sides of the wheel will balance, since we have discovered that wheels of the gauge thickness that we employ are, when rotating at high speeds, easily deflected sidewise by very slight unbalanced pressures on their respective faces. The velocity of the water or other liquid supplied to the entrance end of the ,conduit need not be high since it derives a very high velocity by the centrifugal force imparted by the rapidly revolving wheel, the speed of which would vary from 1200 to 2500 revolutions per minute, depending upon the length of the cut and the nature 01' the material being cut. The volume of the stream should, however, be sufliciently large so that the region covering and surrounding the cut is virtually immersed in the liquid.

We claim:

1. In an abrasive cutting machine, means for clamping the material to be cut, a thin abrasive wheel, a frame on which the said wheel is rotatably mounted, the said frame being pivotally mounted to permit it to tilt and to move the wheel bodily in its plane of rotation, and a member provided with an arcual conduit for liquid mounted in the plane of rotation of the wheel and approximately concentric therewith, said conduit being provided with a narrow slot through which the edge of the wheel may, when tilted, extend into the conduit and rotate therein, said conduit being symmetrical with respect to the plane of travel of the wheel therein.

2. In an abrasive cutting machine, means for clamping the material to be cut, a thin abrasive wheel, a frame on which the said wheel is rotatably mounted,-the said frame bein pivotally wheel-bodily in its plane of rotation, and a member provided with an arcual conduit for liquid mounted in the plane of rotation of the wheel and positioned to discharge liquid to the cutting region, said conduit being provided with a narrow slot through which the edge of the wheel may, when tilted, extend into the conduit and rotate therein.

3. In an abrasive cutting-machine, means for clamping the material to be cut, a thin abrasive wheel, a frame on which the said wheel isrotatably mounted, the said frame being pivotally mounted to permit it to tilt and to move the wheel bodily in its plane of rotation, and a member provided with an arcual conduit for liquid mounted in the plane of rotation of the wheel and approximately concentric therewith, said conduit being provided with a narrow slot through which the edge of the wheel may,

into the conduit and rotate therein. I

4. In an abrasive cutting machine, means for clamping the'material to be cut, a thin abrasive wheel, a frame on which the said wheel is rotatably mounted, the said frame being pivotally mounted to permit it to tilt and to move the wheel bodily in its plane of rotation, and a mem ber provided with an arcual conduit for liquid mounted in the plane of rotation of the wheel and approximately concentric therewith, said conduit being provided with a slot ,through which the edge of the wheel may, when tilted, extend into the conduit and rotate therein, said conduit being symmetrical with respect to the plane of travel of the wheel therein.

5. In an abrasive cutting machine, means for clamping the material to be cut, a thin abrasive wheel, a frame on which the said wheel is rotatably mounted, the said frame being pivotally mounted to permit it to tilt and to move the wheel bodily in its plane of rotation, and a member provided with a conduit for liquid mounted in the plane of rotation of the wheel and positioned to discharge liquid to the cutting region,

' said conduit being provided with a narrow slot through which the'edge of the wheel may extend into the conduit and rotate therein.

6. In an abrasive cutting machine, means for clamping the material to be cut, a thin abrasive 5 mounted to permit it to tilt and to move the when tilted, extend wheel, a frame on which the said wheel is rotatably mounted, the said frame being pivotally mounted to permit it to tilt and to move the wheel bodily in its plane of rotation, and a member provided with a conduit for liquid mounted in the plane of rotation of the wheel and positioned to discharge liquid to the cutting region, said conduit being provided with a slot through which the edge of the wheel may extend into the conduit and rotate therein.

7. In an abrasive cutting machine, means for clamping the material to be cut, a thin abrasive wheel, a frame on which the said wheel is rotatably mounted, the said frame beingpivotally mounted to permit it to tilt and to move the wheel bodily in its'plane of rotation, and a member provided with a arcual conduit for liquid mounted in the plane of rotation of the wheel and positioned to discharge liquid to the cutting region, said conduit being provided with a slot through which the edge of the wheel may, when tilted, extend into the conduit and rotate therein.

8. In an abrasive cutting machine, means for clamping the material to be cut, a thin abrasive wheel, a frame on which the said wheel is rotatably mounted, the said frame being pivotally mounted to permit it to tilt and to move the wheel bodily in its plane of rotation, and a member provided with an arcual conduit for liquid mounted in the plane of rotation of the wheel and approximately concentric therewith, said conduit being provided with a narrow slot through which the edge of the wheel may extend into the conduit and rotate therein, said conduit bein symmetrical with respect to the plane of travel of the wheel therein.

9. In an abrasive cutting machine, means for clamping the material to be cut, a thin abrasive wheel, a frame on which the said wheel is rotatably mounted, the said frame being pivotally mounted to permit it to tilt and to move the wheel bodily in its plane of rotation, and a member provided with an arcual conduit for liquid mounted in the plane of rotation of the wheel and approximately concentric therewith, said conduit being provided with a slot through which the edge of the wheel may extend into the conduit and rotate therein, said conduit being symmetrical with respect to the plane of travel of the wheel therein.

DAR'IREY LEWIS.

WIIFRID L. WALSH. WALTER vB. LASHAR, J a.