US 2163162 A
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Description (OCR text may contain errors)
G. C. WELLS PUMP PI'STON June 20, "1939.
Filed July 6, 1937 k A z /Nl/ENTOR GEORGE C. WLL6 HARRIS,
Patented June 20, 393
f. T E S PUMP PISTON -Application July 6, 1937, Serial No. 151,997
My invention relates to pump pistons with particular reference to pistons employed in slush pumps and the like.
The type of piston involved here comprises a piston body of resilient material incorporating a metal core that is apertured to receive a piston rod. The metal core is subject to practically no wear, but every stroke of a slush pump involves abrasion of the piston body. One of the objects of my invention is to provide a separable core for such a piston whereby the piston body may be replaced, the value of the core not bein included'in the replacement cost.
Another object of my invention is to provide a core construction that in a given size may be combined with a number of sizes of piston bodies. In the operation of a slush pump it is commonly found advisable to reduce'the diameter of the pump cylinder by inserting a new liner.- By virtue of my construction it is necessary, in such a case, to change only the piston body to the new diameter, the original piston core being retained. It will .be apparent that by constructing such a core to flt a number of different body sizes, I obtain a substantial reduction in the number of core sizes that must be manufactured and stocked to accommodate slush pumps ofvarious diameters,
Another object of my invention is to provide an interlocking piston structure that may be readily assembled or dismantled progressively from one end of the piston, whereby the procedure of changing piston bodies may be'greatly simplified. It is contemplated that the piston construction will permit a change of piston bodies without removal of the piston rod from the pump cylinder.
In the interlocked assemblage, flanges are in engagement with complementary recesses. A
feature of my piston is that each of the recesses is formed by the juxtaposition of cooperative members whereby the flange complementary to the recess may be readily engaged or disengaged by axial movement in the assembling or dismantling of the piston.
'A further object of my invention is to provide an assemblage of interlocking members that will provide the strength and rigidity of an integral core casting and that will transmit and distribute forces from the pump rod into the interior of the piston body in a direct manner.
A still further object of my invention is to provide a split piston body with internal reinforcing means to lend rigidity to portions of the piston body adjacent the plane of the split.
The above and other objects of my invention will be apparent from the following detailed description.
In the drawing which is to be taken as illustrative only:
Fig. 1 is an axial section through one form of my piston.
Fig. 2 is an exploded view of the piston with one member shown in phantom to reveal the construction of an embedded reinforcement 10 member.
Figs. 3 and 4 indicate in an exaggerated manner how one core assembly may be employed with difierent sizes of piston bodies, and
Fig. 5 is a modification of my invention adapt- 15 ed for mounting on tapered piston rods.
In Fig. 1 a piston rod I0 is provided, in a well known manner, with an integral flange l I having a conical shoulder l2 on one face thereof. The
end of the piston rod is provided with threads I3 20 for receiving a nut l4 that is similar in configuration to the flange H and has a conical shoulder l5 similar to the shoulder l2. The piston proper comprises a core assembly, generally designated 3, on which is mounted a piston body generally 25 designated I9, the piston body being fabricated of rubber or other suitable resilient material.
In the preferred form of my invention the core assembly comprises three pieces: a hub member 20 at one end of the piston, a similar hub mem- 30 her 2| at the other end of the piston, and an intermediate annular member 22. The hub member 20 base cylindrical portion 23 and an integral end flange 2 3 that is turned axially inwardly to grip the piston body l9. In a similar 35 interlocking relationships maybe provided by 40 the juxtaposition of cooperating members. In the preferred form of my invention, for example, the intermediate annular member 22 has a central radial flange 29 and two cylindrical portions 30 and 3| on opposite sides of the flange, 45
these cylindrical portions being smaller in diameter than theadjacent cylindrical portions 23 and 25 of the hub members 20 and 2|. It will be apparent that'the cylindrical portions 23 and 30 together with the flange 29 form cooperatively so an annular recess 32, and that the cylindrical portions 25 and 3i together with the flange 29 form a second annular recess 33.
To provide the desired character of interlock,-
ing relationship between the body 19 and the core 55 assemblage described, the body is divided into two complementary members 35 and 35, the member 35 having an inwardly directed flange 3'! complementary to the recess 32, and the member 36 having a similar inwardly directed flange 38 complementary to the recess 33.
In the preferred form of my invention, permanently embedded in the body members 35 and 35 respectively, are rigid reinforcing means 40 and 4| adapted to interlock with the core assembly to serve, in effect, as integral parts thereof. In the construction shown in the drawing, these reinforcing means are in the form of metal rings, each having a plurality of holes 42, and these rings are so placed in the two piston bodies that they provide the material for the flanges 31 and 38.
By employing a plurality of reinforcing means, as exemplified by the reinforcing means 40 and 4|, I am enabled to distribute the stresses delivered to the piston body considered as a whole, and to reinforce each separate member of the piston body, especially near the opposing faces of the body members; and by making the body in sections, each of which includes only one reinforcing ring, I am enabled to simplify the molding process and to achieve a highly efficient bond between the ring and the rubber body.
Fig. 1 shows the piston assembled on the piston rod ID with the interlocking parts of the piston clamped together between the conical shoulders l2 and I5. It will be apparent that by simply removing the piston rod nut l4, the interlocking members of the piston may be freely separated and disengaged from each other, as indicated in Fig. 2.
Figs. 3 and 4 have in common the same hub member 45 and the same intermediate annular member 46, but the piston body member 41 of Fig. 3 islarger in diameter than the piston body member 48 of Fig. 4.
The piston rod 50 of Fig. 5 has a tapered portion 5| and a threaded end 52 on which end is mounted a lock nut 53 and a piston nut 54 having the usual conical shoulder 55. The hub member 56 at the inner end of the piston may be shrunk or driven onto the tapered portion 5| of the piston rod in a permanent manner. As shown in the drawing, the intermediate annular member 59 and the hub member 80 at the outer end of.the piston fit loosely over the tapared portion 5| of the piston rod to permit free movement in the assembling or dismantling of the piston. In the normal assembled position of the parts, the core assembly is held together by pressure exerted between the conical shoulder and the hub member 56, the reinforcing ring 6| of a body member 62 being interlocked with the hub member 56 and the annularmember 59, and, in similar manner, the reinforcing ring 63 of the body, member 54 being interlocked with the hub member and the intermediate annular member 59.
The preferred form of my invention, set forth specifically herein for the purpose of complete disclosure, suggests a wide range of structural modifications and changes without departing from the spirit of my invention. I reserve the right to all such changes and modifications that properly come within the scope of my appended claims. a
I claim as my invention:
1. A piston of the class described,.having in combination: a core assembly providing walls forming a plurality of peripheral recesses; a plurality of resilient piston bodies adapted for mounting on said core assembly; and annular rigid reinforcement members permanently embedded in said bodies, said members being complementary to said recesses to be positively confined by the walls thereof and thereby locked against axial movement in either direction, said core assembly being separable at said recesses to release said reinforcement members for replacement of piston bodies.
2. A piston of the class described, having in combination: a flanged hub member at one end of the piston; a second flanged hub member at the opposite end of the piston; an intermediate annular member forming with said hub members a core assembly; a central radialflange integral with said intermediate annular member, said hub members and intermediate annular member being constructed and arranged to form cooperatively two peripheral recesses separated by said flange; two complementary piston body members of. yielding material, each adapted for mounting on one of said hub members to extend over said intermediate annular member; and two rigid annular reinforcing members, one permanently embedded in each of said body members, said reinforcing members being complementary to said recesses and adapted to seat therein abutting said radial flange.
3. In a piston construction, an interlocking combination comprising: two hub members, each having a cylindrical portion and an end flange; an intermediate annular means forming with said hub members a core assembly, said intermediate means having a cylindrical portion of smaller diameter than said hub members and having a central flange whereby two annular recesses are formed by said central flange and cylindrical portions; and a pair of complementary body members adapted to be gripped between said end flanges, each-of said body members having inwardly disposed flanges complementary to said annular recesses.
4. In a piston construction, an interlocking combination comprising: two hub members, each having a cylindrical portion and an end flange; an intermediate annular means forming with said hub members a core assembly, said intermediate means having a cylindrical portion 01' smaller diameter than said hub members and having a central flange whereby two annular recesses are formed by said central flange and cylindrical portions;- apair of complementary body members of yielding material adapted to be gripped between said end flanges and to embrace said cylindrical portions of the hub members and said central flange; and two rigid annular reinforcing members, one embedded permanently in each of said body members, each of said reinforcing members having an annular portion embracing the inner end of the cylindrical portion of the corresponding hub member and having also an inwardly disposed annular flange portion abutting said central flange and seating in one of said annular recesses.
5. A piston of the class described, having in combination: a flanged hub member for one end of the piston; an intermediate annular member in axial alignment therewith, said hub member and annular member being constructed and arranged cooperatively to form a peripheral recess having two oppositely facing annular walls; a piston body of yielding material adapted to bemounted on one of said members; a rigid reber being constructed and arranged cooperative- 1y to form a second peripheral recess having two oppositely facing annular wa11s;' a'second piston body of yielding material adapted to be mounted on said second hub memberi and a second rigid reinforcement member permanently embedded in said second piston body member and adapted to seat in said second recess and-- 5 abut both said walls thereof. a
' GEORGE c. WELLS.