US1995304A - Device for dressing grinding wheels - Google Patents

Description

March 26, 1935.- H. HALLAM 1,995,304

DEVICE FOR DRESSING GRINDING WHEELS Original Filed April 21, 1932 I Patented Mar. 26, 1935 DEVICEFOR' DRESSING GRINDING WHEELS Harry Hallam, Leicester, England, assignor to 7 United Shoe Machinery Corporation, Paterson, V N. .11, a corporation of New Jersey I Originalapplication April 21, 1932, Serial No. I

606,69l.- Divided and this application May 29, 1934, SerialNo. 728,146. In Great Britain lvIa-y. 20, 1931 -5 Claims; (Cl. 125-11) Thisinvent on relates to devices for dressing ahrading wheels and is herein illustrated as embodied in an abrading machine of the character disclosed in my copending applicationfor Let ters Patent of the Uni-ted States. Serial No. 606,691, filed April-21, 1932,- of which this appli: cation is a division. I 3 7 It is an obj ect' of the invention to provide an improved device for dressing. grinding wheels, which device maybe conveniently operated and is so arranged as to render both itself and the abrading tool readily accessible. In accordance with a feature of the invention, there is provided in combination with an abrading wheel a dressing tool I mounted for movement toward and from the wheel, means for pressing the dressing tool with predetermined force against the abrading wheel, means for normally holding the dressing wheel away from the abrading wheel. and operatorcontrolled means for releasing the dressing tool from the holding means to render operatively the pressing means. In the illustrated machine, a relatively weak spring is provided for urging the dressing tool toward the abrading wheel and a relatively strong spring is provided for normally holding the dressing tool away from the abrading wheel. The device is illustrated as mounted upon the hinged door of a dust hood associated with the abrading wheel, so that when the door is open both the dressing device and the abrading wheel will be readily accessible.

These and other features of the invention will be described as embodied in an illustrative machine and pointed out in the appended claims.

Referring now to the accompanying drawing,

Fig. 1 is a view in front elevation showing the head of the machine; and

Fig. 2 is a view in side elevation of the seen in Fig. 1 looking from the left.

The frame of the illustrated machine comprises a vertical column 1 having a head casting 3 at its upper end in which is supported a horizontal shaft 5 extending from left to right of the operator as he stands in front of the machine. The

parts horizontal shaftis provided with fixed and idler pulleys 2 and 4, respectively, and a belt 6 driven from any suitable source of power may be shifted from the idler pulley 4 to the fixed pulley 2 to start the machine. A grinding wheel 7 is secured to the left hand end of the shaft to be rotated thereby. A bracket 9 is secured to the machine head and extends close to the grinding wheel '7 and has bolted to it a circular dust collecting hood l1 enclosing the wheel 7. The hood 11 has an outlet opening inits rear portion, from which outlet opening a suction conduit 87 extendsdowm. wardly. The suction conduit 8'7 is connected to theusual exhaust blower (not shown) for disposing of dust which arises from the operation of the wheel 7. upon the work. 7

In order. to prevent thesurface of the grinding wheel from becoming glazedby its grinding ac tion on insoles a dressing which can be. lowered into wheel 55 is provided contact with'the pe riphery of the wheel andserves by pressing on the ,latter to keepits surface'rough. This dressing wheel'g55 comprises anumber of corrugated steel discs mountedv side by side on a pin 5'7 which .is

secured in the rear end of "a rocker arm 59 which is housed inside the dust hood 11 and is secured at its forward end to a,freely rotatable shaft or pivot 61 whichextends throughthe left hand side of the dust hood surrounding the wheel. v A spring 63 is secured at one end to the arm 59 which carries the dressing'wheel to a hook on the dust hood dressing wheel down on to and at the other end and: tends to pull the the periphery of the pin 67 secured to the hand lever 65.

A spring 73, which is stronger than the spring 63 which is connected to the arm 59 carrying the dressing wheel, is secured to the hand lever 65 and tends to pull the latter rearwardly so that the pin 67 secured to the hand lever presses against the rearward end of the slot 71 formed in the cap member 69 and thus lifts the arm 59 carrying the dressing wheel away from the grinding wheel. By pulling the hand lever 65 forwardly against the action of the spring 73 the pin 67 can be retracted from the rearward end of the 510 the spring 73 to press the t 71; thereby enabling dressing tool against the grinding wheel. It will be noted that the pressure of the dressing toolagainst the grinding wheel is not derived from the lever 65 but from the spring 63, and is accordingly predetermined. If, however, agreater pressure is desired, the operator can pull the lever 65 forwardly far enough to cause the pin '71 to bear against the forward end of the slot 71, thus transmitting additional pressure to the dressing tool.

hand lever 65 is released Immediately the the dressing wheel is raised owing to the rearward movement of the hand lever under the action is connected to it.

of the spring 73 which In order to allow a free access to the grinding wheel the left hand side of the dust hood which carries the pivot 61 for the link 59 is formed as a door '77 which is secured to the dust hood on a vertical pivot pin 79 near to its rear side. A thumb screw 81 normally holds the door 77 clamped in closed position but by release of the thumb screw the door can be swung open and the grinding Wheel can be easily seen and reached.

Furthermore, when the door is open the dressing tool and its associated mechanism are also accessible. Having described the invention, what is claimed as new and desired to be secured by Letters Pat ent of the United States is:

1. In combination with an abrading wheel, a dressing tool mounted for movement toward and from the abrading wheel, means for pressing said dressing tool with predetermined force against the abrading wheel, means for normally holding- -said dressing tool away from the abrading wheel,

dressing tool mounted for movement toward and from the abrading wheel, a relatively weak spring for urging said dressing tool toward the abrading wheel, an operating lever, a lost-motion con-' nection between said operating handle and said dressing tool, and a relatively strong spring acting upon said operating lever in a direction to maintain said dressing tool out of engagement with the abrading wheel, whereby, when said operating lever is manually moved in opposition to said relatively strong spring said relatively weak spring will be free, by reason of said lost-motion connection, to press said dressing tool with predetermined for'ce against the abrading wheel.

4. An abrading machine comprising an abrading wheel, a dust hood associated with said abrad- 'ing wheel, a shaft journaled in and extending through a wall of said dust hood, an arm secured to said shaft within said dust hood, a dressing tool carried by said arm and movable into engagement with said abrading tool upon swinging movement of said arm, a relatively weak spring constructed and arranged to urge said dressing tool toward said abrading wheel, an operating handle freely pivoted upon said shaft outside of said dust hood, a lost-motion connection between said operating handle and said shaft, and a relatively strong spring acting upon said operating handle to cause the operating handle, through said lost motionconnection, normally to hold said shaft in a position to maintain said dressing tool out of engagement with said abrading wheelagainst the opposition of said relatively weak spring, said relatively weak spring serving, when the operating handle is moved in opposition to said relatively strong spring, to press said dressing tool against said abrading wheel. 7

5; An abrading machine comprising an abrading wheel," a dust hood partially surrounding said wheel, said hood having a hinged door adjacent to a side face of said wheel, a tool carried by said door for dressing the operating surface of said abrading wheel, and operator-controlled means for causing said dressing tool to engage the operating surface of said abrading wheel whensaid door is closed.

HARRY HALLAM.

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