US2388434A - Abrasive cut-off machine - Google Patents

Description

Nov. 6, 1945. w. A. PHILLIS ABRASIVE GUT-OFF MACHINE v 2 Sheets-Sheet 1 Filed June 14, 1944 INVENTOR. WILLIAM A.PHILLI flrromverl Nqv. 6, 1945. w. A. PHlLLlS I ABRASIVE CUT-OFF MACHINE 2 Sheets-Sfleei 2 Filed June 14, 1944 INVENTOR. WILLIAM A. FH/Lus Patented Nov. 6, 1945 ABRASIVE CUT-OFF MACHINE William A. Phillis, Warren, Ohio, assignor to Beaver Pipe Tools, Inc., Warren, Ohio, a corporation of Ohio Application June 14, 1944, Serial No. 540,245

9 Claims.

This invention relates to a cut-off machine having means for positioning the work, a motor driven rotating abrasive disc and means for bringing the disc into engagement with the work. The general object of the invention is to provide such a machine in an extremely simple and at the same time efficient form. Another object of the invention is to provide for the ready and convenient energization of the motor and manual movement of the rotating disc to its work. Another object is to provide a simple means for protecting the operators hand which holds the work from inadvertent engagement by the abrasive disc. Other objects and features of the invention will be apparent from the following detailed description of a preferred embodiment illustrated in the drawings.

In the drawings, Fig. 1 is a front elevation of my machine; Fig. 2 is a side elevation looking at the left hand end of Fig. 1; Fig. 3 is a vertical section in a plane indicated by the line 3-3 on Fig. 1; Fig. 4 is a fragmentary perspective of the base of themachine showing the work positioner and indicating an article to be cut lying therein.

In the drawings, l indicates a base of special form as hereinafter described in detail; 30 an arm pivoted at the rear to the base so as to be movable in a vertical plane, and 40 a motor carried by the arm and carrying on its armature shaft an abrading disc 45. Mounted in the base is a spring device 50 acting upwardly, as hereinafter explained, against the arm, and counterbalancing the weight of the motor and arm to maintain the arm normally in its uppermost position, as indicated in Fig. 2. The arm is provided with a handle adapted to be grasped by the operator, who may at the same time operate an electric switch to energize the motor and then swing the motor and rotating disc downwardly to bring the disc into engagement with the work held by the operators other hand in the work positioner, carried by the base.

I will now describe more specifically the construction of the different elements above outlined.

The base In comprises a substantially rectangular member having a table-like top portion, flat for the most part, as indicated at [2; suitable downwardly extending edge flanges l3, l4 and bracing internal webs l5. The work positioner formed on the base comprises a pair of parallel ridges ll presenting a V-shaped longitudinal channel interrupted by a cross groove [1, which an article i indicated at A in Fig. 4 as a pipe or rod.

The front left hand corner of the table 12 is lowered as indicated at I8, and along the right side of this lowered portion is a guard comprising an upwardly extending web 19. The lowered left hand front corner referred to provides space for the operator's hand to grasp the article to be held in the V-shaped work positioner, while the plate i9 forms a thumb guard preventin his hand reaching the region of the cross groove I1 and thereby protecting it from inadvertent contact with the abrasive disc. The operators hand in holding the pipe or rod Ais roughly indicated by the broken lines B in Fig. 4.

At the ends of the base I prefer to form it into a pair of downwardly facing trough-like portions providing handles by which the entire machine may be readily carried from place to place.

At the rear, the base has a somewhat higher portion than the table [2 from which rises a pair of ears 22, which form the support for a cross shaft on which the motor-carrying armis v mounted.

The swinging arm 30 is of three parts, namely, a rear portion 3|, pivotally mounted at 25; a forward part which carries ahandle 35, and an intermediate part, which may be the motor frame itself, or a ring embracing the frame. As shown in the drawings, the motor frame has an annular boss 32 which is formed in diametrically opposite regions into fiat pads 33 and 34 to which the flattened ends 36 and 31 of the front and rear part I are bolted. The result is a unitary arm in which the motor is interposed.

I have mentioned the spring device which normally holds the arm 30 and the motor in elevated or idle position. This is best shown in Fig. 3. As there appears, this device comprises a downwardly facing cylindrical cup 5| which is slidably journalled in the base, and a helical compression spring 52 occupying such cup and seated on a plug 53 adjustably mounted in the base. I have shown the base provided with an internal annular wall 26 providing a well in which the spring member is mounted. Preferably a bushing 55 forming a bearing for the cup is tightly mounted in the well, the cup slidably fitting the interior of the bushing. The plug 53 is screwthreaded on its exterior and. threaded directly into the wall 26. Suitable means, as an angular opening 5'! in the base of the plug 53, enables it to be turned up or down to adjust the force of the spring against the cup 5|. The upper end of the cup 5| engage a suitable rubbing portion 38 on the under face of the member 3| of the swinging arm.

The force of the spring 52 is enough to more than counter-balance the weight of the arm 30 and the motor and other parts carried by the arm, so that the arm is normally held in its uppermost position. In this position a flattened portion 39 on the arm engages a flattened face 21 on the top of the base frame, thereby limiting further upwardly movement of the arm.

I provide adjustable means to limit the downward movement of the swinging arm, 50 that the abrading disc may always reach to the bottom of the groove I! in the work support without danger of cutting the base. This stop is made adjustable so that as the disc Wears away in use the stop can be lowered from time to time to allow the disc of reduced diameter to reach the bottom of the work holding groove. The stop is shown at 60 in Figs. 1, 2 and 3, and comprises a headed screw threaded in a boss 28 of the base. A suitable jam nut 6| locks this screw in any set position.

The motor is of any suitable type and the disc is connected in any suitable manner to the armature shaft thereof. The motor frame carries an extension portion 4| which by suitable arms 42 supports a guard 43 for the disc. The guard has a vertical plate, lying along the right hand side of the disc, and a flanged edge 44 extending for something over a half circumference about the periphery of the disc.

The left hand side of the guard is normally closed by a plate 46 having ears 4'! overlapping mating ears on the guard periphery 44 and connected by a hinge pintle 48. At its diametrically opposite edge, which is at the front of the machine, the plate is locked to the guard frame by a bolt 49 hinged to the guard and normally occupying a slot in the plate.

The protecting plate 46 and the back plate of the guard 44 are of similar contour and are incompletely circular, being of the shape shown in Fig. 2. This exposes a comparatively small portion of the abrasive disc beneath the guard. Such portion, however, is sufi'icient to pass through any article which may be placed in the work positioner beneath the disc in its elevated position as shown in Fig. 2.

It will be understood from the description given that in cutting off a pipe or other article, it is merely necessary for the operator with his left hand to press the article in the work support and with his right hand grasp the handle 35 and after turning on the switch to pull .down the handle, so that the rotating disc passes rapidly through the article, cutting it off as desired.

To increase the efficiency and rapidity with which the machine may be operated, as well as to keep the rotation of the disc under ready control of the operator, I locate the switch for the motor on the rocking arm adjacent the handle 35. As shown in Figs. 1 and 3, the handle 35 is hollow and at its left hand end is formed into a housing which forms the means of connecting the handle at that end with the handle pad 36 rigidly secured to the swinging arm. The housing 19 contains the motor switch. This switch has a swinging operating handle H extending through a removable front plate 12 of the switch box. A two-Wire cable extends from the motor and source of supply through the hollow handle into the switch box 10, to terminals controlled by the lever H.

As the operator grasps the handle 35, with his right hand, he may at the same time with his thumb throw the switch II to turn on the motor, which rotates in but one direction. Then as he pulls down on the handle 35 the disc cuts through the positioned article in the work support into the groove H. In such operation by the right hand of the operator on the handle 35, the operator may readily hold the article to be cut by his left hand, and is well protected in doing so by the upright thumb guard, which as shown in Fig. 1 is a safe distance away from the region of operation of the disc.

When the job is finished, the operator releases his downward pull on the handl 35, enabling the spring to return the parts to idle position, and at the same time with his thumb he naturally swings the switch lever H to shut off the motor.

It will be seen that my cut-off machine is quite simple and may be constructed relatively cheaply. The entire :base may be a single integral casting. The whole machine is comparatively light and may be readily carried from place to place, and as soon as its electric circuit is connected to the source of supply it is ready for operation. The adjustment of the stop to increase the possible downward swinging of the frame as the disc wears is readily effected with an ordinary wrench to release the jam nut, and manual turning of the head of the stop screw, which preferably has a knurled exterior for this purpose. When it is desired to replace the abrading disc by a fresh disc it is merely necessary to loosen the wing nut on the clamping bolt 49, swing the bolt outwardly and swing open the door 46 of the guard, thus rendering the disc and its clamping members accessible.

I claim:

1. In an abrasive cut-ofi machine, the combination of a base having an upwardly facing work seat, an arm pivoted to the rear portion of the base and extending forwardly, a motor carried by the arm, an abrading disc operated by said motor, an upwardly acting spring device mounted in the base and tending to elevate the arm, said device comprising a downwardly facing cup slidably mounted in the base and bearing at its upper end against the under side of the arm, an abutment adjustably mounted in the base, and a compression spring occupying the cup and constrained between said abutment and the top of said cup.

2. In an abrasive cut-off machine, the combi nation of a base having a work seat on its upper face in which work may be manually held, a swinging arm, a motor-driven abrading disc carried by the arm and adapted to move across the region of the work seat, and a thumb guard carried by the base and extending upwardly adjacent to the plane of operation of the disc as it passes across the work seat.

3. In an abrasive cut-off machine, the combination of a base having an upwardly facing seat to position an article to be cut, an arm pivoted to the rear of the base and extending forwardly, a motor and an abrading disc carried by the arm, said disc being adapted to intersect the space above the work seat when the arm is lowered, said base having an upstanding .web alongside of and adjacent such space of the work seat to protect the hand of the operator in engaging the work resting in the work seat. .f

4. In an abrasive cut-01f machine, the combination of a base having a pair of parallel ridges providing a V-shaped seat for an article to be cut, a transverse groovethrough saidridges in which an abrading disc may pass, an arm pivotally connected to the base, a motor-driven abrading disc on the arm adapted when the arm is lowered to occupy said groove, a thumb guard carried by the base and extending upwardly alongside of said groove to protect the hand of the operator holding the article in the work seat.

5. The combination of a base having on its top a pair of parallel ridges defining a V-shape seat between them for an article to be out, there being a transverse groove across the ridges, the front left hand corner of the base being lowered to provide space for the operators hand holdin an article in the seat, an upstanding web carried by the base at the right of said space and at the left of the groove to protect the thumb of the operators left hand holding an article in the work seat, an arm pivoted to the base and carrying a rotatable abrading disc adapted to enter said groove when the arm is lowered.

6. The combination of a base having on its top a pair of parallel ridges defining a V-shape seat between them for an article to be cut, an upstanding web carried by the base at the right of the space for the operators left hand holding an article in the seat to protect the thumb of that hand, an arm pivoted to the base and carrying a motor driven rotatable abrading disc, said disc being adapted to move across the seat in a plane at the right of said upstanding web when the arm is lowered, a handle mounted on the arm in position for engagement by the operators right hand, and an electric switch for controlling the motor, said switch being at the left hand end of the handle and adapted to be operated by the operator's right thumb while his right hand is on said handle.

'7. In an abrasive cut-off machine, the combination of a base having an upwardly facing work seat, an arm pivotally attached to the base at its rear portion and extending forwardly and formed intermediately with a motor mounted in the arm in front of the pivot of the arm, an abrasive disc carried by the motor and rotated by the armature shaft of the motor adapted to coact with an article to be cut lying inthe work seat, the work seat having an intersecting groove to receive the disc, a handle on the forward end of the arm, and means tending to maintain the arm and motor elevated with the disc above the work seat.

8. An abrasive cut-01f machine comprising, in combination, a base, an arm pivotally carried by the base and comprising three parts in succession, namely, a rear part pivoted to the base, an intermediate part comprising the frame of a motor on a horizontal axis connected to the rear part, and a forward part connected to said motor frame and carrying a handle, an abrading disc carried by the motor and rotated by the armature shaft of the motor, and a spring acting against the rear part of the arm and tending to elevate it.

9. An abrading cut-off machine comprising a base, a work positioner on the base, an arm pivotally carried by the base and overhanging the work positioner, said arm comprising three parts in succession, namely, a rear part pivoted to the base, an intermediate motor frame, a horizontal axis connected to the rear part, and a forward part connected to said motor frame and carrying a handle, an armature mounted in the motor frame, a switch for the motor mounted on said forward part, an abrading disc driven by the motor, a stop limiting the upward movement of the arm, and a spring acting against the rear part of the arm and normally maintaining it against the stop.

WILLIAM A. PHILLIS.

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