US2200966A - Piston - Google Patents

Description

y 1940. A. LQNELsoN 2,200,966

rxsmou Original Filed June 2, 1934 INVENTOR,

Patented May 14, 1940 2,200,966

UNITED STATES PATENT OFFICE.

PISTON Adolph L. Nelson, Detroit, Mich, assignor to Bohn Aluminum & Brass Corporation, Detroit, Mich, a corporation of Michigan Original application June 2, 1934, Serial No. 728,663. Divided and this application March 24. 1937, Serial No. 132,681

2 Claims. (01. 309-43) The present invention relates to an improved and the inner wall of the ring ll provides a conpiston, and particularly to a light-weight piston tinuous contour. A slot 13 extends vertically adapted for use in internal combustion engines. 'through thrust face 12 and forms two separated The invention provides a piston in which the wings l4 and IS. The lower end of this slot-is 5 piston skirt is formed with a vertical slot and circuitously arranged so as to form a hook I6 5 with a part that extends across one end of the attached to wing l4 and hook l1 attached to slot and arranged to prevent spreading of the 'wing Hi. The inner faces of these two hooks enslot when a lathe or grinder center is inserted gage each other as illustrated to prevent spreadin the open end of the piston and to permit ining of the lower end of the skirt, but extra clear- 10 ward yielding of the skirt when pressure is creance is provided as shown to permit movement of 10 ated between the skirt and the cylinder in which the wings l4 and i5 toward each other to narrow the piston is operated. the slot [3. This application is a division of my applica- When a piston constructed in this manner is tlon Serial No. 728,663, filed June 2, 1934. placed on lathe or machine centers, one center While preferred forms of the invention are engages the head of the piston and a tapered cen- 15 disclosed herein for purposes of illustratiom variter is pressed inside the lower open end of the ous changes may be made in the structure withpiston. This tapered center would, in the about departing from the spirit of the invention. sence of the restrictor, spread the slot l3 and en- In the drawing: large the lower end of the skirt, thus interfering Figure l is a side elevation of a piston emwith accurate finishing of the piston. But the 20 bodying the invention. presence of the restrictor prevents any such Figures 2 and 3 are views similar to Figure 1 spreading of slot I3. but showing modified forms of the invention. On the other hand, the piston is yielding so The invention can be applied to any preferred far as concerns the cylinder in which it is later type of piston, and in the species of Figure 1 it assembled. Whenever the cylinder exerts pres- 25 is shown applied to a piston of the type illustrated sure on the skirt of the piston, as when a rise in in Nelson Patent No. 1,830,172 in which the extemp ra causes the piston to xp faster, pension of the skirt is controlled by steel struts. than the cylinder, the restrictor does not inter- In these figures the piston includes the head fere with the closing-in or narrowing of the slot H), a lower ring II and a thrust face I! which exl3. 30 tends upwardly from the lower ring. In Figure 2 the restrictor is a ring I8 that has The invention is'particularly adapted for use a snug fit w t Sides f a Ve- T ends 0! on pistons formed of light-weight material, such the ring ov p a have hooks l9 and 20 that as aluminum alloy. Pistons formed of these macoop ra i a m r similar to the hooks of terials usually have a higher rate of thermal Fi expansion than the cylinders in which they are The rest c o 2| of Figure 3 is a member that used'an'd theyshould be constructed so they will lies in a groove and is flush with the outer face not slap when cold nor seize when hot. It is a f t e Sk t T e d heads 22 engage in common practice to provide such pistons with a e e s in the Skirt t D L Clearance 40 vertical slot which permits the skirt to yield ciryond the ends of the headsfl to permit the skirt 40 cumferentially as it expands into contact with 0 yield d i" the cylinder wall. One drawback in the use of Any ui l m a f x mp steel. can such vertical slots is that if the slotted piston is be used for the restrictors. placed on centers for a finishing operation, such I claim:

as grinding or boring the piston pin holes, the A piston comprising a head, a Skirt with a 45 skirt spreads and is therefore in a distorted conslot extending vertically therein and forming two dition during the finishing operation. I separated wings, a hook member formed oneach According to the present invention a restrictor 0 Sa d Wings, d hook members being erpart extends across at least one end of the slot, engaged to prevent spreading of the slot when a so the restrictor part being arranged to prevent outlathe center is placed within the open end of the ward yielding but to permit narrowing of the piston, the skirt being provided with clearance slot under pressure. which permits closing in of the slot when pressure In the preferred construction illustrated in is created betweenthe skirt and the cylinder in Figure 1 the lower ring ll continues uninterwhich the piston is operated. ruptedly around the circumference of the skirt, 2. A piston comprising a head, a skirt with a ll t'wo separated wings, each wing provided with a is created between the skirt and the cylinder in hook member, said hook members being interwhich the piston is operated. 5 engaged to prevent spreading of the slot when a lathe center is placed within the open end of the ADOLPH L. NEUSON.

slot extending vertically therein, the lower end piston, the being provided with clearance I of the slot being circuitously arranged to provide which permits closing in of the slot when pressure,

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