US1577735A - Valve-truing tool - Google Patents

Description

CII

Patented Mar. 23, Y1926.

rin-fl'ruaT sam/iras .EDWARD I/AARLE, 02Ev OAKLAND, CALFORNIA.

VALVE-TRUING TOOL.

Application filed August 27, 1919.' Sera1 Noi 329,235.

for truing or dressing thefaces of" valvesk especially theV poppet valves of' internal combustion engines.

An object of theinvention is to provide a truing tool which will insure accurate re-l sults' notwithstanding the characteristic deformation of the valve stem due to wear.

Another object ofthe invention is to provide a device such as will enable the valve to be quickly and Securely placed in posi-k tionfor the truing operation.

The `invention possesses other objects and features ofadvantage, some of which, with the foregoing, will-be set forth in the following description of the preferredv form of my invention which iSillnStrated inthe drawings accompanyingand'forminga part of the specification; It is to be understood that l do not limit myself to the showing made by the said drawings and description, as I may adopt variations of the preferred form within the scope of my invention as set forth in the claim. l

Referring to said drawings:

Fig. 1 is a plan view of the truing tool, the valve being shown positioned therein.

Fig. 2 is a vertical section of the device, the plane of the section being indicated by the line 2-2 of Fig. 3.

Fig. 3 is a vertical section taken on the line 3 3 of Fig. 2.

Frequently the poppet valves of an internal combustion engine become warped or misshapened so that they do not seat properly. The valve face must then be trinnned until the original circumference and taper obtain once more. During this trimmingV operation the valve is usually supported by mounting the valve stem for rotation in a pair of aligned clamps. It is imperative that these clamps should so hold the stem that the valve will rotate in aliixed cooperative relation with the cutting blade of the truing tool and thereby become accurately trimmed. Since the clamps are generally two in number they will therefore engage the stem at two spaced points intermediate its ends. If the valve stem is ofthe saine diameter thruout its length then the clamps will hold the valve properly. However the stem invariably liecomesinuchl thinner at that portion which is continu# ally pressing against the sides of its bear ing when the engine is operating, due to the pressure ofthe intake or exhaust' gases. Since lthe length of the stems for the diii'erent engines vary considerably, it is almost G5 invariably the case that unless labor entailing 4adjustments aremade, one ofi the tool clamps will engage a thin section of the stein and the'othera thick section, thereby throwing the valve completely out of alignment and making it impossible to trim the valveY with any degree of accuracy.

In accordance with my invention the valve stem automatically assumes a correct position and therefore insures an accurate cutting of the valve.

detailed description of my invention follows:

The apparatus comprises a pairrof jaws 2 andB between which thestem el. of the valve 5 is arranged to bel positioned.' The jaws are pivoted together at one edge, the eyes 6 and 7 and pin 8 disposed on the inner side of the jaws being partly provided for that purpose. The jaw 2 is preferably` 85 formed with an integral supporting member 9 which may be set in a vise to anchor the tool if desirable.

Means are provided as hereinbefore mentioned, for insuring the correct positioning 90 of the valve stem.4 Formed on the inner sides of the jaws and preferably integral with the eyes 6 and 7 are a plurality of' spaced longitudinally aligned teeth l0 and 12. T he teeth l0 of the jaw 2 are arranged to lit in the spaces 13 between the teeth l2 of the jaw 3 and vice versa the teeth l2 are arranged to engage the spaces 14 of the jaw 2. By referring to Figure 2 it will be clearly seen that when a valve stem having a worn portion such as at l5, is inserted between the jaws, at least one tooth of each jaw will engage the undeformed portion of the stem at both the forward and rear end of the jaws, thereby insuring the proper l truing of the valve. .j

The teeth: are each provided with a V-shaped recess 16 thereby providing a four point contact between each pair of teeth that are in Contact with the stem. This construction has several advantages over a three point contact, since a better bearing is provided within which the stein may rotate and a mnch smaller error in alignment ot the valve will prevail in case an insultieient number of teeth engage the valve stem.

Simple means are Vprovied for normally maintaining the jaws in an extended position and :tor drawing said jaws together when it is desired to grip the valve. Enoireling the pin 8 and interposed between the aws is a spring 17 which presses against the inner sides of the jaws and therehvY tends to keep the jaws extended. Engaging the free edges oit the jaws 2 and 3 is a screw threaded bolt 1S formed. with a reotangular neck 19 which loosely engages a correspondingljV shaped aperture 19 provided in the jaw 2. rlhe threaded end of the holt extends thru an enlarged aperture 20 formed in the jaw 3. A winged nut 2l engages the holt on the outer .side of the jaw 3 while the head 22 of the holt`hears against the outer side ot the jaw 2. lilith this con struction the jaws majv he opened or Closed hy simplyv turning a single nut, thereliijT saving considerable time dispensing with a nnmher of loose parts.

rlfhe jaw 2 is provided at one end with a Cutting hlade 23 which has its cutting edge E34 disposed in. the path of the valve tace The opposite end of the jaw 2 is provided with an adjustable screw 2G which is arranged to engage the free end of the valve stem to limit the amount that the valve majT be trimmed.

In operation ot the device the valve stem mvp/,vas

is inserted in the recesses i6 and the winged nut 2l rotated until the stein is properly gripped. The screw 26 is then adjusted so that the face of the valve properly contacts with the cutting blade. To rotate the valve it is convenient to use an ordinary brace (not shown) provided with a key 27 that can he inserted in the recesses 28 provided in the valve.

l claim:

A valve truing tool, Comprising a pair ot jaws pivotally connected adjacent one edge and arranged to he longitudinally disposed along` the valve'stein, a plurality of longitudinally spaced teeth on the inner side oi each jaw arranged to cooperatively engage onljT full-sized portions of said stern throughout its length, the teeth of each aw being arranged to engage in the spaces between the teeth ot' the other jaw, a cutting member adjustablv Secured to one end of one of said jaws and having its cutting portion positioned to lie in the path of the valve face when the valve is operatively held in the tool, means resiliently urging said jaws apart a single means for holding said jaws together to retain the teeth in engagement with said stein and means provided on the jaw carrying said cutting member for limiting the movement of the valve against said Cutting member.

ln testimony whereof, I have hereunto set my hand at Oakland, California, this 16th day of August 1919.

EDWARD LAPARLE.

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