US2184489A - Piston expander - Google Patents

Description

Dec. 26, 1939. H. DI OW, 2,184,489

PISTON EXPANDER Filed March 22, 1938 Inventor Q X w ,By

A iiorneys Patented Dec. 26, 1939 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to power pistons and more particularly to power pistons of the type used in internal combustion engines.

Specifically the invention has reference to what may be termed a re-camer, the invention being in the nature of an expansible element adapted to be inserted within the piston and, when arranged within the piston, to act thereon in a manner to expand the piston at diametrically opposite points thereon into contact with the cylinder wall to the end that piston slap will be eliminated and the rings of the piston will have greater life as a result of the piston being held straight or perpendicular within the power cylinder.

The invention together with its objects and advantages will be best understood from a study of the following description taken in connection with the accompanying drawing wherein:

Figure 1 is an elevational view of a piston with parts broken away and showing the invention as applied thereto, and

Figure 2 is a transverse sectional view through the piston with the invention applied thereto.

Referring to the drawing by reference numerals it will be seen that 5 indicates a conventional piston, such as for example, a Ford V-8 solid skirt steel piston.

Mydevice is indicated by the reference numeral 6 and is in the form of an elliptical split ring of resilient material such as steel that is adapted to fit within the piston in a manner clearly shown and to act on the skirt of the piston to force the walls of the piston at approximately the point A and B on said walls into intimate contact with the wall of the cylinder, it being noted that the point A is adjacent to the split in the re-camer 6 while the point B is diametrically opposite to the point A and to the split in the re-camer 6. The re-camer 6 thus forcing the piston skirt out at the points A and B will cause the piston skirt to contract or narrow at approximately the 'points C, C, C and C thus providing sumcient clearance for oil and expansion under heat.

Also to accommodate the reinforcing ribs I provided on the inner side of the skirt of the piston the re-camer element 6 has oppositely disposed portions thereof pressed inwardly as at 8, and as clearly shown in Figure 2. As is well known, and as shown in Figure 2 each reinforcing rib I has its free edge sloping upwardly. and inwardly from a point adjacent the bottom of the piston to the point where it joins the tubular boss 9. The inwardly pressed parts 8 are placed over the lower parts of these ribs, as shown in Figure 1, and the upwardly and inwardly sloping free edges of the ribs preventthe split ring from moving upwardly for when the piston is expanded at the points A, B by the ring the contraction at the points 0, C will cause the ribs to closely approach or engage the parts 8, it being seen that in Figure 2 the piston is not shown as being distorted by the ring but is in true cylindrical shape. Thus when the piston is distorted the ribs 1 will approach very closely to or touch the parts 8 and thus the ribs'will hold the ring against upward movement in the piston and will hold it close to the inner flange III at the bottom of the pis- It is to be noted, however, that the parts 8 of the ring do not contact the ribs with sumcient force to tend to expand the piston at the points where the ribs occur as the ribs simply act to prevent the rings riding upwardly in the piston. It will also be seen that the ribs i prevent circumferential movement of the ring in the skirt.

My re-camer is especially designed for use with pistons of the solid skirt'type as distin-' guished from pistons having split skirts; and is distinguished from' a piston expander, since an expander applies pressure at all points around the piston skirt while, as above noted, my recamer applies pressure to the skirt at only two diametrically opposite points thereon, and to an extent eliminating piston slap and a rocking of the piston back and forth at the bottom of the piston.

Thus my re-camer will be found especially useful in reconditioning motors having worn pistons and cylinder walls since by use of the piston recamer piston rings, substituted for the old and removed rings, will have greater life and mileage capacity. N

It is though that a clear understanding of the construction, utility and advantages of an inven- 1 tion of this character will be had without a more detailed description.

Having thus described the invention what is claimed as new is:

In combinatioma piston including a solid substantially cylindrical skirt, a pair of diametrically opposed internal bosses in said skirt, a pair of re.- inforcing ribs on said bosses, respectively, depending therefrom and downwardly diverging relatively, and a split resilient ring in said skirt having inwardly bowed portions interengaging with said ribs, respectively, for holding the ring against upward and circumferential movement and said ring reacting outwardly against diamet-' so rically opposite portions of the skirt intermediate said bosses, said ring intermediate said portions being free from contact with said skirt and loosely engaging said ribs, whereby said skirt is urged I into transversely elliptical form.

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