US1543409A - Expansible piston - Google Patents

Description

June 23, 1925.

O. WIGGERS ET AL EXPANSIBLE PISTON Filed Jan. 22. 1923 2 Sheets-Sheet 1 was m5 W? 1% m B 1 June 23, 1925.

O. WIGGERS ET AL EXPANS IBLE P'iSTON Filed Jan. 22. 1923 2 Sheets-Sheet 2 IN VEN TOR.

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Patented June 23, 1925. D

'\ UNITED STATES PATENT'OFFICE.

OTTO WIGGERS AND JOHN WIGGEBS, 0F WALLA WALLA, :WA'SHINGTON.

EXPANSIBLE PISTON.

Application filed January 22, 1923. Serial No. 614,259.

To all whom it may concern: Be it known. that we, O'r'ro WIGGERS and JOHN WIGGERS, citizens of the N etherlands,

residing at Walla Walla, in the county of Walla Walla and State of Washington, have invented certain new and useful Improvements in Expansible Pistons, of which the following is a specification.

This invention relates to 'expansible pistons, such as used in internal combustion engines, and has as one of its objects to provide a piston that may be expanded to. fit

the cylinder of the engine when wear has occurred and to maintain constant the increased size until further wear occurs.

A further object of the invention is to provide" an expansible piston that is practically as cheap to manufacture as those in use at the presenttime and which, by reason of its expansion will provide greater service.

WVith this and other objects in view reference is had to the acco panying drawings in which of a piston Fig.' 7 shows a sectional view of part of a piston with one form of in place;

Fig. 8 is a similar viewof Fig. 7 showing a modification of the expanding means;

'Fig. 9 is a plan view of ,a special head for a fastening bolt, taken'on the line 99 of Fig. 7. J

Fig. 10 is a side elevation of the fastening bolt shown in lan in' Fig. 9;

. Fig. 11 is a slde elevation of a tapered bolt expanding means as shown in Fig. 8;

Fig. 12 shows an enlarged perspective view of a wedge substitute for a tapered bolt; and I Fig. 13 shows another modified form of expanding means, in an inverted position.

Having reference to the-drawings like nu merals refer to like parts throughout the several views and the numeral 1 refers to a piston provided with the usual. skirting 2 carrying the wrist pin bosses 3, and guide portions 4. l

In the skirting 2 is provided'a series of slots, which, as they are united, will be termed a slot, that together form an anchor shaped slot 5 consisting of a diagonal slot 6, tal slot 8.

.The out for the diagonal slot is made by starting the out at the point shown as 9 a vertical slot 7, and a horizonmidway between the bosses 3 and at a point I nearly opposite the upper part 10 of the bosses 3, and cutting-downward and inward to a point 11 near and approximately on ,a level with the lower part 12 of said bosses; the vertical slot 7 is out longitudinally of the piston starting at the lower edge 13 of the skirting and cutting up to intersect the diagonal slot 6 at the point 14; and the horizontal slot 8 is out slightly above and parallel to the lower edge 13 and is bisected by the vertioalaslot 7.

It is well known inthe art that pistons should be made as light as possible therefore they are hollowed out, as at 15, leaving a sufiicient bearing surface 16, however, the wearing side, i. e., on the side opposite to thewrist pin, to properly guide the piston in the cylinder, not shown.

The skirtin then at this bearing part 16 is obviously 0% fact that it"is the bearing art that must contact the cylinder wall, ma es it essential that the slots should be made herein to provide the proper expansion of the piston.

Within the piston is mounted the expanding means of which there are several modifications shown in the drawings, all consistthicker metal, which with the ing however, of the one principle of forcing an expansion by means of a wedge.

One means for expandingthe iston consists of projections 17 having wedge shaped recesses 18, similar to that shown in Fig. 6, positioned one on each side of the slot 5 and made integralwith the skirting 2, the recesses being designed to receive a wedge 19 which when forced therein by any suitable means will expand the skirting 2, slots 20 being cut in a reinforcing rib 21 to provide for equal expansion of the skirting.

Another means of expanding the skirting consists of mounting an expansible ring 22 Within the skirting, the ring being prov ded with abutting ends 23, both of which are recessed wedge shape to accommodate the wedge 19 which in turn is forced therein by a suitable means. In using the ring 22 it is desirable to have some means of preventing undue movement in a direction longitudinal of the piston and for this purpose ribs 24; are provided, the ribs being out integral with the piston.

The wedges 19 used for the purpose of expansion may be conical in shape, as shown in Figs. 7 8,

11 and 13, or may be rectangular as shown in Fig. 12, and the wedges may be moved, i. e. forced into the wedge shaped recesses 18, by means of a bolt 25 having an irregular shaped head 26 to engage the side wall 27 of the skirting 2 to prevent turning, with the conical shaped wedge 19 having a nut 28 to threadedly engage the bolt 25 (see Fig. 7) wherewith to draw the wedge the proper distance in the recesses, or with a bolt 25 provided with a conical shaped head, which in turn is provided with a slot 29 to accommodate a driver, as shown in Fig. 8. In both of these cases a projecting lug, 30 may be used to draw against, and cotter pins 31 may be used to prevent accidental loosening of the arts, and in the case of the means, shown in Fig. 7, the bolt 25 is assembled in the lug by means of a slot 32 cut therein, as shown in Fig. 9.

In Fi 13 is shown another modification and in t is case the head 33 of the boltbears against the ring 22, and the wedge 19, which is slidable on the bolt, is seated by the castellated nut 34, held in place as before by the cotter pin 31.

Where the rectangular wedge is used, the

recesses are correspondingly designed to register therewith and may be used where a more perfect fit of. the parts is required.

In use, the piston first being slotted, the wedges are inserted to place and by screwing are brought up to the proper place, this being determined by micrometers or other means.

Obviously in the means designed as shown in Fig. 8,'the piston would have to be removed to make the expansion as the cotter pin 31 must first be recessed which can only be done by removing the piston, sufiicient at least, to uncover the cotter pin when it may be removed. In the other designs, however, adjustments may be made while the piston is in place.

' Having thus described our invention, we claim- 1. In an expansible piston, a slotted skirt-.

ing, a slotted reinforcing rib within said skirting, the slots thereof providing for equal expansion, wedgeshaped projections one on each side of'the slot in the interior of said skirting, and means to expand said projections and with them said skirting.

2. In an expansible piston, a slotted skirting, projections on the interior of said skirt- 7 ing, positioned one on each side of the slot and provided with wedge shaped recesses, lugs extending inwardl from said skirting, and a tapered bolt in t readed engagement with said lugs and in sliding engagement with the wedgeshaped recesses of the projec' tions to expands said piston.

In testimony whereof O'rro WIGGERS and JOHN IVIGGERS affix their signatures.

OTTO WIGGERS. JOHN WIGGERS.

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