US1978315A - Valve-grinding machine - Google Patents

Description

1 G. LEMAY VALVE GRINDING MACHINE Oct. 23, 1934.

-' Filed Oct. 27, 1932 3 Sheets-Sheet 1 III Afforngy.

Oct. 23, 1934. G. LEMAY VALVE GRINDING MACHINE Filed Oct. 27, 1932 3 Sheets-Sheet 2 Oct. 23, 1934. G. LEMAY V LVE GRINDING MACHINE 5 Sheets-Sheet 3 Filed Oct. 27, 1932 HI [Wen/i521 dzwim/e 56%?- Affornq y,

Patented Oct. 23, 1934' PATENT OFFICE VALVE-GRINDING MACHINE- Gustave Lemay, La Courneuve; France Application October 27, 1932, serial No. 639,876 In France October 28, 1931 r 1 Claim. (01. 51-we l My invention has for its object a machine for grinding valves set at any angle. My improved machine also provides means for trimming with a diamond the valve grinding wheels, for sharpening the cutters used for, machining the valve seats and for grinding the inner and outer surfaces of small parts.

The chief features of my improved machine are the following: Its frame is semi-curved and its base stretches widely beyond the operative parts, forming thus a bed with no gap therefor and providing for the machineperfect steadiness and rigidity which are obviously the necessary conditions for a proper grinding operation. The

motor embedded at the centre of the frame provides steadiness for the wholemachine and is protected against the metalparticles produced throughthe grinding. Moreover its location allows the different transmission means to be disposed inside the frame, which does away with the necessity of pulleys and belts outside the machine. At the same time'I obtain thus a vertical traction on the wheel-carrier, which is the,

most rational method of controlling a grindingwheel. The motor-shaft carries a double pulley for controlling on one hand the-wheel and on the other a transmission controlling -i n its turn the vertical shaft actuating the sleeve of the special chuck holding the valve to be ground. The end of the transmission shaft may carry means for driving a yielding transmission controlling a wheel system for grinding valves, de vices for boring holes, for removing the scale from the valve stem or the like operations.

The valve-holding chuck comprises three jaws the movements of which are perfectly equal whereby the valve may be held with its axis properly centered and without any possibility of vibration.

The rigid large-base carriage affords means for transverse movement while the wide and rigid valve-carriage affords means for longitudinal movement. Its head is centrally controlled from the pivoting base through a helical pinion whereby said head need not be overhung.

I have shown in accompanying drawings by way of example, a form of execution of my invention.

Fig. 1 is a front view of the machine, partly cross-sectional.

Fig. 2 is a side-view.

Fig. 3 is a plan view partly sectional.

Fig. 4 is a cross section along line IV-IV of Fig. 1.

Fig. 5 shows the means for mounting the diamond-carrying ring used for grinding the wheel.

Fig. 6 is a longitudinal cross-section of the valve-holding chuck.

Fig. 7 is a view in a plane perpendicular to that of Fig. 6 of the parts inside the chuck, the outer driving sleeve of which has been removed.

Fig. 8 is a cross-section along line VIIIVIII. of Fig. 5.

" Fig. 9 is a cross-section along line IX--IX of Fig. 5.

Fig. l0"is a longitudinal cross-section of a modification.

Fig. 11 is a cross-section thereof along line XI-XI of Fig. 10.

The machine executed according to my invention comprises in the first place a framed wherein is housed the electric motor b. On the upper part of the frame is disposed the carriage c on which lie the roller bearings for the spindle d of the wheel e. This carriage is adapted to move transversely along the slide f formed on the frame, under the action of any known or suitable means. In front of the grinding wheel e is arranged the chuck g adapted to hold the valve to be ground. This chuck may be directed in any desired direction with reference to its support It adapted to slide longitudinallyalong the slide 2' formed on the frame. The chuck is set in the desired direction through the pivot 7'1 formed on the chuck holder 7'. This pivot is adapted to rotate in a circular recess provided in the support h. The chuck is locked. in the desired direction through the bolt It. Through this pivot 7'1 and along the axis thereof passes the vertical spindle Z the upper end of which carries a worm m meshing with a helical toothwork n on the chuck g. The lower end of the spindle l carries a pulley 0 controlled by a belt 10 passing over the transmission shaft q along which it is adapted to slide. This transmission shaft is controlled in its turn through the belt r actuated by the pulley s on the motor shaft. To the latter is also keyed another pulley t actuating through a yielding belt u. and a pulley v, the wheel spindle d.

The Whole control device described is arranged inside the frame a which is entirely closed except for the opening a: admitting air to the motor.

When it is desired to make use of the machine for trimming the grinding wheel, the diamondcarrying ring a is fitted to the rear of the chuck holder as shown in Figs. 4 and 5. In this case the chuck holder is brought through its direction controlling means in the direction opposed to that used for normal operation.

The chuck used in the machine comprises an outer sheath g which is driven as explained hereinabove by the motor of the machine. This sheath is constituted by a hollow cylinder the front of which forms a frustocone g1. The three jaws 2 arranged in three equidistant radial planes slide along the inside of this frustocone through the oblique surfaces 2a forming the outside of one end of the jaws. These jaws 2 .extending parallel to the axis of the chuck are provided at their ends with inner gripping parts 34 and at the end opposed to the oblique surfaces 2a with reversely sloping surfaces 21) bearing against the inside of the frustoconical recess 5a provided in the thrust ring 5. These jaws are spaced'one with reference to the other by the jaw-spacing parts 6 secured each through a screw '7 to the frustoconical front end g1 of the chuck sleeve.

Inside the ring 5 may slide axially the hollow push-rod 8 urged by the spring 9 to move towards the front of the ring 5 and to bear against the rear end 20 of the three jaws, which end is cut perpendicularly to theaxis of the chuck, A nut 10 screwed over the rear end of the push-rod prevents its falling out of the ring 5 while the chuck is being mounted or dismantled. The push-rod which serves to bear against the three jaws with an equal pressure provides a perfectly accurate simultaneity of motion of the three jaws whereby the centering of the valve held by them is always perfectly true.

The jaws 2 may slide between the spacing parts 6 and are held or urged backwards and outwards against the action of the spring 9, each by a spring 11. These springs 11 have one end 11a secured in one spacing part and extend freely through the free space to the side of this part into the hole 12 provided in the corresponding law.

The thrust ring 5 is held down by the locking ring 13 screwed inside the sheath g.

The stem of the valve to be ground is disposed along the axis of the chuck between the jaws 222, after which the locking ring 13 is screwed into the sheath 9 until the gripping parts 3-4 of the jaws bear against the periphery of the rod. This is provided by the action of the locking ring 13 on the thrust ring 5 which is thus caused to engage through its frustoconically recessed end 5a the sloping rear ends 2b of the jaws 2 and to bring these ends nearer the axis. At the same time the jaws, urged forwards by the pushrod 8, slide through their slopingsurfaces 2a along the inner conical surface of the frustoconical front end 9, of the chuck whereby the front ends of the jaws are also brought nearer the axis of the chuck.

The slopes given to the ends 2a and 2b of the jaws being the same, the elastic pressure exerted by the end 8a of the push-rod 8 on the rear ends of the jaws 2 which are perpendicular to the axis will move the said jaws 2 towards the axis through perfectly equal amounts, while the jaws remain perfectly parallel to their original position. This ensures a perfectly true centering of the valve stem and allows the chuck to hold stems the diameter of which varies inside very wide limits.

This movement of the jaws is made against the action of the springs 11 the yielding portion of which is deflected towards the front and towards the axis. Therefore, when the ring 13 is unscrewed, the springs act, through their elasticity, on the jaws which are thus brought back to their starting position gradually as they are released by the thrust ring and its push-rod 8.

Figs. 10 and 11 illustrate a modification wherein the jaws are urged towards one another by a conical spring 14 one coil of which passes through each jaw. Thus this coil deformed by the advance motion of the jaws when the locking ring is screwed down returns through its elasticity, the jaws into their starting position when the ring is unscrewed again.

What I claim is A valve grinding machine comprising a motor, a grinding wheel, a vertical pivot, a spindle passing axially through said pivot, a worm at the upper end of the said spindle, a chuck sleeve adapted to rotateround a horizontal axis and carried by the pivot, a helical gear on said sleeve operatively engaged by the worm, a plurality of equidistant jaws having outwardly frustoconical ends, said jaws being adapted to slide inside the sleeve, a thrust ring, frusto-conical guides for the jaws, integral with the sleeve and with the ring respectively, yielding means urging said ring against the rear end of the jaws for moving the ends of the latter axially and radially along their guides through equal distances, means for controlling the thrust ring, yielding means urging the jaws back into their starting position, an idler shaft, a first belt between said motor and grinding wheel for rotating the latter, a second belt connecting the motor to said shaft for revolving the same, and a third belt between said shaft and spindle for transmitting a rotary movement thereto.

GUSTAVE LEMAY.

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