US1708500A

US1708500A - Piston

Info

Publication number: US1708500A
Application number: US247605A
Authority: US
Inventors: Phelps M Freer
Original assignee: ALEXANDER C HAMILTON; CHARLES H LEWIS
Current assignee: ALEXANDER C HAMILTON; CHARLES H LEWIS
Priority date: 1928-01-18
Filing date: 1928-01-18
Publication date: 1929-04-09
Anticipated expiration: 1946-04-09

Description

April 9, 1929. FREER 1,708,500

PISTON Filed Jan. 18, 1928 2 Sheets-Sheet 1 p l .9, 1929; P. M; FREER 1,708,500

PISTON Filed Jan. 18, 1928 2 Sheets-Sheet 3 INVENTOR BY flee 1 '7 W A jTORNEY Patented Apr. 9, 1929.

UNITED STATES PATENT OFFICE.

I PHELPS M. FREEROF DETROIT, MICHIGAN, ASSIGNOR OF FORTY-NINE PER CENT T ALEXANDER C. HAMILTON, OF DETROIT, MICHIGAN, AND FIFTY-ONE YER CENT T0 CHARLES H. LEWIS, OF CLEVELAND, OHIO.

PISTON.

Application filed January 18, 1928. Serial No. 247,605.

The invention relates to improvements in pistons designed particularly for use in internal combustion engines, as described in the present specification and illustrated in the accompanying drawings that form part of the same.

The objects of the invention are to provide a composite piston comprising a head of light material having high heat conducting qualities, and a skirt of maximum wearing qualities joined to the head by a simple form of spring bracelet.

In the drawings- Fig. 1 is an elevation View of the piston with substantially one-quarter broken away.

Fig. 2 is a plan view of the piston from the under side.

Fig. 3 is a side elevation detail view of the head with one-quarter thereof broken away.

Fig. 4 is a side elevation view of the spring bracelet.

Fig. 5 is a side elevation view of the sklrt.

Fig. 6 is a detail View of the aligning pin.

7 is a plan view of the spring bracelet.

Fig. 8 is a detail view of a modified form.

Fig. 9 is a partially broken side view of the piston showing a modification of the means for maintaining concentricity of the head and the skirt.

Fig. 10 is a side elevation of the modified spring bracelet embodied in the construction shown in Fig. 9.

Fig. 11 is a sectional View taken on line iii-11 of Fig. 9.

Fig. 12 is a partially broken side elevation of the skirt member employed in the construction shown in Fig. 9.

Fig. 13 is a fragmentary sectional view taken on the line 1313 of Fig. 9. illustrating the manner in which the locking fingers engage their cooperating grooves.

Like numerals of reference indicate corresponding parts in each figure.

lower end, and extends downwardly from a locking shoulder 15.

The head as described is preferably made of cast aluminum or other light alloy having maximum heat conducting qualities, while the skirt 16 is made of a metal such as a. cast nickel iron alloy or the like, which possesses high wearing qualities and a very low coefiicient of expansion.

The skirt 16 is made of a plain cylindrical form having the small ledge or inwardly extending flange 17 around the bot-tomfor reinforcing purposes, and likewise the inwardly extending flange 18 around the top, the flange 18 being finished on its under side 19 with a bevel of a definite angle for purposes as hereinafter described. The head and skirt 16 are cast and finished as separate pieces, and are then joined by a spring bracelet 20 formed with the inturned lower end 21 and the upwardly and outwardly extending

fingers

22 and 23, the fingers 22 being slightly longer than the fingers 23, so that the bracelet may be sprung around the lower part 12 of the head similar to a piston ring, with the lower int-urned end 21 fitting snugly in the groove 14 on the head.

To assemble the parts the skirt is pressed upwardly against the head, causing the

fingers

22 and 23 of the bracelet 20 to spring inwardly until the flange 18 passes the ends of the fingers and abuts the flange 15 on the head, at which time the fingers are of such length that they will just have cleared the flange 18 and will bear against the bevelled under side 19 of said flange.

he fingers. being of unequal length, will press outwardly to different extents. and will always assure taking up of play between the skirt and the head at the pistonand yet will permit of the necessary movement be tween the head and the skirt due to unequal ex mansion between a normally cold temperature and a temperature that may be attained when the piston has been running even under excessive compression conditions in the. engine cylinder. I

To maintain true concentricity between the head and the skirt at all times, lateral holes 2 1 are drilled at the juncture of the head and the skirt, and pins 25 are dri into the said holes and peencd therein in suitable manner. These pins are preferabl four in number, as shown in Fig. 2, thougl i three may sufiice, and it will be noted that the diametrically opposite pins will prevent any corresponding lateral movement of the head and skirt, and thus hold them concenwithin the corresponding slots 36 which closelv embrace the sides of the same and there ore act in the same manner asthe pins 24 previously described, to maintain true concentricity between the head and the skirt.

As indicated in Fig. 13, the sides of the grooves 36 arepreferably tapered so that the fingers 35 in drop ing into the grooves 36 will engage the si es of the grooves before they can reach the bottoms thereof. This construction insures close fit of the fingers 35 with the sides of the grooves so as to prevent any possible lateral movement of the skirt portion 16- with respect to the collar- 20, and at the same time provides a construction which allows greater manufacturing tolerances in the width of the fingers 35 and grooves 36 than wouldotherwise be possible.

In order to prevent possible rotation of the head with respect to the skirt in this construction, inwardly extending projections 37 are formed at the inner edge of the bracelet 20, and matching depressions 38 are formed in the bottom of the groove 14 so that when the bracelet 20 is in operative position it is locked against rotation to the head.

It will be readily understood that if it is desired to make the skirt of a sheet metal, the upper part thereof may be turned downwardly to form spring fingers as shown in detail in Fig. 8, wherein the head is shown at 26 with the extending lower portion 27 formed with a beveled flange 28 at its extreme lower end, and the skirt of drawn material is shown at 29 with its upper end turned inward at 30 to abut the head, and the fingers 31 extending downward in such turned-in portion to spring against the beveled flange 28.

Other modifications may be made in the construct-ions without departing from the spirit of the invention, which broadly covers the uniting of the head and skirt by means of the spring fingers of different lengths, which maintain a constant pressure of the head against the skirt, and yet permit the necessary differences in expansion, and the provision of means for maintaining the concentricity of the head with respect to the skirt.

What I claim is:

- 1. A piston comprising a head, and a skirt sleeved over a portion of the head and having spring fingers of unequal length for connecting the two together.

2. A piston comprising a head, a skirt sleeved over a portion of the head, and a ring-like member surrounding said head within said skirt for connecting the two together, said ring-like member being provided with resilient fingers of alternately different lengths.

3. A piston comprising a head member and a skirt member secured together in sleeved relationship by a plurality of spring fingers of different lengths.

4. A piston comprising a head member and a skirt member secured together in sleeved relationship by a plurality of spring fingers, and means for maintaining the concentricity of said members.

5. A piston comprising a head member and a skirt member secured together in sleeved relationship by a plurality of spring fingers, and means for preventing rotational movement of one of said members relative to the other thereof.

6. A piston comprising a head member and a skirt member secured together in sleeved relationship by a coronal collar provided with s ring fingers, and means for maintaining t e concentricity of said members comprising a plurality of radially extending pins engaging both of said members.

7. A piston comprising a head member and a skirt member secured together in sleeved relationship by spring fingers and means for maintaining ooncentricity of said members comprising radial pins inserted in said members at their juncture.

.8. A piston comprising a pair of members secured together in sleeved relationship by means of a collar rovided with resilient fingers, and means or preventing rotation 10f one of said members relative to said col- 9. A piston comprising a head member and a skirt member secured together in sleeved relationship by a collar provided with s ring fingers, and means for preventing relative rotation of said collar with respect to said head member.

10. A piston comprising a pair of members secured together in sleeved relationship by a plurality of connected spring fingers, and means for preventing rotation of either of said members relative to said fingers.

11. A piston comprising a air of members secured together in sleeve relationship by a collar provided with spring fingers,

said collar closely fitting one of said members, and certain of oppositely disposed said fingers being received in notches in the other of said members.

12. A iston comprising a head portion and a s 'rt portion secured together in sleeved relationship by resilient means, and means for maintaining the concentricity of said portions.

13. A piston comprising a head portion and a s irt portion secured together in sleeved relationship by resilient means, and means disposed on generally opposite sides of said piston for preventing movement of one of said rtions laterally thereof on the other of sai portions.

14. A piston comprising a head portion and a sleeve portion, resilient means locking said portions against axial movement relative to each other, and o positely disposed means engaging both sai portions for preventing movement of said head portion laterally thereof on said skirt portion.

15. A piston as described in claim 14 in which said means comprises a pair of fingers carried by one of said portions and a pair of cooperating notches in the other of said portions; the sides of said notches adapted to engage the sides of said fingers being tapered whereby to prevent said fingers from contacting against the bottoms of said notches.

PHELPS M. FREER.