US 2623798 A
Description (OCR text may contain errors)
Dec. 30, 1952 R. I... SKINNER 2,623,798
PRESSURE SEALING MEANS Filed Dec. 9, 1947 IN VEN TOR.
wai. ji /22241" w 744% Y Patented Dec. 30, 1952 PRESSURE SEALING MEANS Ralph Leslie Skinner, Bloomfield Hills, Mich, assignor, by mesne assignments, to Robertshaw- Fulton Controls Company, Greensburg, Pa., a
corporation of Delaware Application December 9, 1947, Serial No. 790,478
A metallic-reed pressure-seal has heretofore been. devised for use with two companion elements or members reciprocatory with relation to one another, such as an internal-combustion engine piston and its housing cylinder, or, for another example, an airplanev landing-wheel strut and its cooperating fluid-containing cylinder, but it has been discovered that it is sometimes desirable, when the pistons or cylinders are made of a material softer than that of the sealingreeds, to employ a material of synthetic rubber or comparable substance, so that long life can be obtained without excessive wear, and, at the same time the desirable characteristics or properties of the resilient material sealing-means may be availed of.
In accordance with the principles of this innovatory invention, such desirable result is satisfactorily and. efficiently accomplished by having a metallic part or element or preferably, but not necessarily, tempered metal used as.- the support with a synthetic-rubber or other pliable agent or medium vulcanized or cemented to the metal part, or stated slightly differently, the metal member is employed as the supporting means for the more, pliable. and less abrasive material of the reed or support.
One main object of the new and advantageous device is to have the synthetic material orother resilient material cemented or vulcanized to either one or both sides of such steel or metal support or reed, but preferably on the side of the reed or support adjacent to the imposed fluid-pressure in the cylinder, that is to say, the side of the seal to which the pressure is subjected.
An outstanding aim or design of the current invention is to supply a construction of thetype and style referred to which is simple injstructure and hence economical to produce, which is efficient in action, which is of comparatively long life, which is unlikely to become damaged or injured in ordinary service, but, of course, in time it will wear out.
To enable those skilled in or acquainted with this art to understand the invention fully from both structural and functional standpoints, present preferred embodiments thereof have been illustrated in the accompanying drawing, forming a part of this specification, and to which ref erencc should be had in connection. with the following detailed description, and in the several views of such drawing like mechanical parts have been supplied with the same reference numerals.
In this drawing:
Figure 1 is a central, longitudinal, partial section through a piston or plunger and its cylinder equipped with one form of the improved sealing-means;
Figure 2 is an enlarged fragmentary portion of Figure 1;
Figure 3 is a partial view of the sealing-means when not in operative position in the cylinder;
Figure 4 is a transverse section on line 44 of Figure 1; and
Figure 5 is a fragmentary section analogous to a portion of Figure 1 and presenting a modified form of structure.
Referring first to the construction portrayed in Figures 1 to 4 inclusive the cylinder ll containing the fluid under pressure has within it a reciprocatory piston or plunger I2, the two parts being slidable longitudinally with relation to one another, as, for instance, the cylinder may be the stationary part of an internal-combustion engine or of a pump and its piston or plunger may slide therein when performing its useful function, l3 being the rod or stem of the part [2 and I4 its screw-threaded counterpart projecting from the opposite side of the piston against which the contained fluid under pressure is imposed.
As is clearly depicted, on its forward or pressure side the piston l2 has a marginal or peripheral, circular flange I5 with an oblique or sloping, circular, inner-surface against which bears one face of the novel pressure-sealing means comprising a hollow, sheet-metal, truncated-cone reed 16 the external diameter of which is such as to cause it to bear on the inner surface of the cylinder whereby its edge is in sealing engagement therewith.
Vulcanized or cemented to one or to both of the parallel, obliquely-disposed surfaces of this metal reed is a thin layer 11, or i! and I8, of flexible resilient material, such as synthetic-rubber or kindred or approximative material, the external diameter of such one or both layers I1 and I8, as the case may be, being slightly greater than the inner-diameter of the cylinder on which such stratum bears, or strata bear, edgewise.
In preparing the sealing-member the flexible or resilient portion I! on the pressure-imposed side of the plunger or piston has the longer edge* portion [9 which assumes the position shown in Figure 3 when the sealing-means is not in the cylinder.
If the outer edge of the metal-reed i6 is ground to accurately shape it, the resilient part [9 will temporarily occupy a greater diameter than that of the reed itself, but, as shown, as the grinding is accomplished and terminated the marginal'portion of the flexible member I! will assume the relation indicated in Figure 3 when not in the cylinder ready to satisfactorily perform its portion of the sealing function.
As is fully indicated in the drawing, this coated or partial-covered metallic reed i6 is firmly held in place on the piston by a disc 2|, with a sloping or tapered edge, held on the threaded member 14 by a suitable nut 22.
If in time a small annular space between the V inner surface of the cylinder and the outer edge of the reed develops due to Wear it will be so close and shallow that even at extreme pressures in the cylinder the flexible portion [9 of the pressure-seal will not be caused to extrude or be forced out through such minute circular gap between the reed on the piston and the cylinder.
Even before such possible wear on the reed might occur the resilient covering I! assists the reed IS in adequately and perfectly sealing the space between the piston and the cylinder;
In some installations, this novel construction may be used to advantage where the cooperating surfaces to be sealed are not hardened.
Figure 5 illustrates a modified construction and in this example a plurality of similar converging and nested reeds 25 and 26 are used in offset relation, such pair of reeds having inwardly-extended flanges or parts 28, 28 in direct overlapping arrangement and in surface contact with one another and against which a flat collar 29 is firmly held by a nut 3| on a screw-threaded stem correponding to the part I4 in Figure 1, with a lockwasher 33 intervening. The outer active parts of the reeds 25 and 26 are spaced apart as shown and are edgewise in sealing contact with the inner round surface of the cylinder Ill and the pressure face of each such reed has the resilient ring of material 32 cemented or vulcanized thereto with its outer margin extended slightly beyond the edge of its metal support or reed 25 or 26, as the case maybe.
The manner in which this multiple seal functions will be readily understood from the foregoing description, the sealing action being performed both by the metal-reed and by its coating or covering.
Those acquainted with constructions of this general kind will readily appreciate that the present invention is not necessarily limited and rev stricted to the precise and exact details illustrated and described and that reasonable modifications may be availed of without departure from the heart and essence of the invention and without the loss or sacrifice of any of its substantial benefits and advantages.
Whereas this invention has been illustrated an described in connection with relatively reciprocatory interfitting cylindrical members, it should be borne in mind that in many cases it can be employed satisfactorily and eificiently with elements which are rotary with relation to one another.
This application is a continuation-in-part of my former patent application Serial No. 658,255, Pressure Sealing Means, filed March 29, 1946, now abandoned.
1. A pressure seal for pistons and the like comprising a packing including a thin metallic reed of essentially uniform thickness having the form of a hollow truncated cone and a continuous circular free outer edge, an annular strip of resilient material adhesively secured to the forward sloping face of said reed, said strip projecting beyond the outer edge of the reed and forming a narrow,
flexible, annular flap in front of and beyond the periphery of said reed, and a second annular strip of resilient material adhesively secured to the rear sloping face of said reed, the outer edge of said second strip terminating a substantial distance behind the corresponding edge of said reed but projecting laterally from the reed sufficiently so that the outer edges of the reed and the strip are essentially coincident.
2. A packing for pistons and the like comprising three annular sealing members each havin the form of a hollow truncated cone, said sealing members arranged in nested relation and adhesively secured to each other, the middle sealing member being essentially thin and of flexible metallic composition, the foremost and rearznost sealin members being thicker than said metallic member and of rubber composition, said foremost sealing member projecting beyond the outer ,edge of said metallic member and forming a narrow, flexible, annular flap in front of and beyond the periphery of said metal member, said rearmost sealing member terminating a substantial distance behind the periphery of said metal member but projecting laterally of the metal member sufficiently so that the outer edges of the membersare essentially coincident.
3. A pressure seal comprising a packing including a pair of spaced, thin, metallic reeds of hollow conical conformation, each being essentially uniformly thick and having a continuous circular free outer edge, and a pair of correspondinglyv shaped sealing members of resilient material, one
interposed between the reeds and theother overlying the forward face of the foremost metallic reed, said one sealing member projecting beyond the periphery of the rearmost reed but terminating a substantial distance behind the correspond-v ing edge of said foremost reed, said other sealing.
member projecting beyond the periphery of said foremost reed and forming a narrow, flexible, annular flap in front of and beyond the periphery of the reed.
4. A pressure seal for pistons and the like comrising a packing including a thin backing reed of rigid, nonresilient materialand of essentially uniform thickness, said reed having the form of a hollow truncated cone and. provided with a continuous, circular, free outer edge, an annular strip of resilient material secured to the forward sloping face of said reed, said strip projecting beyond the outer edge of the reed and forming anarrow, flexible, annular flap in front of and beyond the periphery of said reed, and a second annular strip of resilient material adhesively se cured. to the rear slopin face of said reed, the outer edge of the said second strip terminating a substantial distance behind the corresponding edge of said reed but projecting laterally from the reed sufficiently so that the outer edges of the reed and the strip are essentially coincident.
RALPH LESLIE sKINNER.
REFERENCES CITED The following references are of record in th file of this patent:
UNITED STATES PATENTS Number 7 Name Date 1,601,187 Myers Sept. 28, 1926 1,762,692 Widemah June 10, 1930 1.945 .52e Foehr Feb, 6, 1934 2,182,226 Geise Dec. 5, 1939 2,417,840 Rodgers Mar. 25, 1947