Claims
- 1. In a pump comprising at least two separate cylinder housings, each cylinder housing defining a cylinder with an axis, the axes being parallel and spaced apart; a pair of pistons, each piston being reciprocable in a corresponding one of the cylinders so as to reciprocate along the axis of the corresponding cylinder to vary a working volume of the cylinder; a motor positioned between the cylinder housings and driving the pistons so as to reciprocate the pistons; a pair of head members, each head member being fastened to a different one of the cylinder housings; and at least one tube spanning the head members, wherein the tube provides fluid communication between the head members;
- the improvement wherein:
- a monolithically formed head which is common to both of the cylinder housings and is a single piece of continuous material includes the head members and the tube so that the tube is joined to each head member with a fluid tight and fixed rigid connection provided by the material of the monolithic head continuously joining the tube to each head member, the head being rigid so as to assist securing the housings in a fixed orientation relative to one another.
- 2. The improvement of claim 1, further comprising another tube spanning the head members and providing fluid communication between the head members, and wherein the other tube is formed integrally with the head members as part of the single piece of continuous material of the monolithic head, the material of the monolithic head providing a fluid tight and fixed rigid connection between the other tube and each head member.
- 3. The improvement of claim 1, wherein the single piece of continuous material of the monolithic head defines a web which spans the tubes and is joined integrally with the tubes.
- 4. The improvement of claim 3, wherein the web is joined integrally directly with the head members.
- 5. The improvement of claim 1, wherein the motor is fixed between the cylinder housings without fasteners joining the motor to the cylinder housings.
- 6. The improvement of claim 5, further comprising a spacer sleeve between the cylinder housings and wherein a press fit connection joins the spacer sleeve and each of the cylinder housings.
- 7. The improvement of claim 5, further comprising a pair of bearings, one of the bearings being press fitted into each cylinder housing, and wherein each bearing is press fitted onto a shaft which is driven by the motor.
- 8. The improvement of claim 1, wherein the tube is spaced from the motor so as to provide an open space between the motor and the tube, said open space being adjacent to the tube.
- 9. The improvement of claim 1, wherein the head is monolithically cast of a metal material.
RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application No. 08/671,849, filed Jun. 28, 1996.
US Referenced Citations (25)
Foreign Referenced Citations (3)
Number |
Date |
Country |
295 08 399 U |
Aug 1995 |
DEX |
7-310651 |
Nov 1995 |
JPX |
1 542 926 |
Mar 1979 |
GBX |
Non-Patent Literature Citations (2)
Entry |
Thomas Compressor Pump, Field Service Manual, 2619CGH147-932, Thomas Industries, Inc., 1996. |
Joseph Shigley, Mechanical Engineering Design, 3rd Ed., McGraw-Hill, pp. 63-65, 1977. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
671849 |
Jun 1996 |
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