US1330915A - Tool eor sure aging valve-seats - Google Patents

Description

M. B. SKINNER.

TOOL FOR SURFACING VALVE SEATS.

APPLICATION FILED SEPT.20.I918.

1 ,3 3 O, 9 1 5 Patented Feb. 17, 1920.

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MORTIMER B. SKINNER, 0F WILMETTE, ILLINOIS.

TOOL FOR SURFACING VALVE-SEATS.

Specification of Letters Patent.

Application filed September 20, 1918. Serial No. 254,940.

To all whom it may concern:

Be it known that I, MORTIMER B. SKIN- NnR, a citizen of the United States, and a resident of Wilmette, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Tools for Surfacing Valve-Seats, of which the following is a specification.

My invention relates to tools for surfacing the seats of valves. Its principal object is to provide simple, strong and easily operable means for surfacing the valve seat as part of the operation of restoring the fit between valve-head and seat in internal combustion engines, such as in automobiles, after the parts have become worn in service, and means for making such repairs by the ordinary mechanic found in garages, and without the use of power machinery.

A prime specific object is to provide a simple form of device of the character described in which the cutter is maintained tightly upon the seat provided therefor whereby a true surface may be out upon the part being operated upon. Other objects and advantages will appear hereinafter.

In the accompanying drawings, which form a part of this specification, I have illustrated these improvements in what I now consider the preferred form, Figure 1 being a sectional view of an engine part with the improved reseating tool in operative position therein; Fig. 2 being a medial vertical section of the cutter at right angles to the view of Fig. 1, Fig. 3 being a top and sectional view as on line 3-3 of Fig. 1, and Fig. 4: being a fragment of a pilot stern of a different diameter from that of Figs. 2 and 3.

The tool illustrated comprises a cutter head 10 which is provided with a diametrical slot or recess 11 adapted to accommodate the outter 12 snugly yet with enough looseness to permit it to be inserted and removed readily. The cutter head 10 is also provided with a threaded axial hole or recess at 18 adapted to accommodate the threaded endl i of the pilot stem 15 or 16, which pilot stem may be of various diameters, as illustrated, so as to fit rotatably in valve stem openings of various sizes in different makes or sizes of engines.

The function of the pilot stem 15 or 16 is to maintain the head 10 in a truly central relation to the valve seat being operated upon so that the cutter 12 will be carried in circular lines. Pilot stems have been heretofore suggested on cgtter heads for such purpose. The head 10 is milled diametrically forming what may be termed a bottom wall 17 which constitutes seat or rest for the cutter 12. This wall or seat 17 is a plane surface at right angles to the axis of the pilot stem 15 and the cutter 12 is provided with a flat surface adapted to rest upon the seat 17. A hole or recess 18 is provided midway of the ends of the cutter 12 to receive the tapering end of the screw 19 threaded radially into the head 10 at right angles to the direction of the slot 11. By tightening the screw upon the cutter 12 with the end of the screw in engagement with the hole 18 the cutter is centrally adjusted and maintained against its longitudinal movement.

What may be termed the upper portion of the head 10 is provided with an axial recess 22, which is screw threaded to receive the threaded portion 23 of the driving shank 24:. Where the cutter 12 is provided with cutting edges, as 25, which are so formed as to take hold when the head 10 is rotated in the usual clock-wise direction (viewing the device from the top as illustrated) the threads 23 of the shank 24C and those of the recess 22 will be right hand threads; or in other words, the shank 24: will thread into the head 10 when the shank is rotated in the operative direction of rotation of the head and cutter. In the device illustrated the end portion 26 of the shank 2a bears directly upon what may be termed the top surface of the cutter 12. It will thus be valve seat has become irregular from un-.

equal wear, the tendency of the end portions of the cutter doing the resurfacing has been to follow the irregularities of the old valve surface and substantially to reproduce them in the new surface, due principally to the fact that the cutter has not beenheld with sutficient rigidity to prevent this yielding or rocking, as upon a middle screw such as 19.

Patented Feb. 17, 1920.

For rotating the cutter of the upper end of the stem 24 is squared and tapered at 30 for engagement by the jaws of a brace or breast drill. I also provide a lever bar 31 slidable in the cross-hole 32 in the shank, and at the upper end of the shank I provide the pintle 33 upon which loosely rests the hand-piece 34. In making a good job or resurfacing it is important that theshank 24; be maintained in a constant direction. I find that this cannot be done where the pressure is applied by one or two hands to such a cross bar as 31, glmlet or anger fashion;

but that such -constant direction may be maintained if the downward pressure be applied axially by one hand and upon a suiiiciently large and pivoted cap or hand-piece, as 34:, while the rotative movement is applied with the other hand, as upon the bar '31. I have claimed this feature in my copending application Serial Number 189,539, filed Sept. 4, 1917, on tools for surfacing valve seats.-

An advantage of the present construction is that the several parts may be readily separated from each other and carried in a small case or box.

I claim:-

ll In a tool of the character described, the combination of a cutter head having a seat therein for a cutter, a cutter resting upon said seat, said cutter having cutting edges arranged to cut when the head is rotated in a given direction, a driving shank threaded axially into said head and having the end portion of the shank bearing against said cutter on the side thereof opposite said seat to hold the same tightly upon said seat, the

enacting threads of said cutter and of said shank being in such direction that when rotating said head and cutter by said shank the tendency oi? the shank is to thread more tightly against said cutter.

The combination with the elements of claim 1 of means for centering the cutter in the cutter head.

3. The combination with the elements of claim 1 of pilot means for centering the cutter head with respect to the valve seat to be operated upon.

at. In a tool of the character described, the combination of a cutter head having a seat for a cutter, a cutter resting against said seat, and clamping means for holding the cutter tightly upon said seat, said clamping m ans includin a driving shank threaded axially into the cutter head in a direction toward said seat with threads which lead the shank into the head when the shank is rotated in the operative direction of rotation of the head and cutter.

5. The combination with the elements of claim l of a screw device carried by the cutter head t'or centering the cutter therein.

6. The combination with the elements of claim l of a pilot stem projecting axially from the cutter head for centering the cutter head with respect to the valve seat to be operated upon.

7. The combination with the elements of claim 4 or a pilot stem projecting axially from the cutter head for centering the cutter head with respect to the valve seat to be operated upon.

MORTIMER B. SKINNER.

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