US3327639A

US3327639A - Reciprocating liquid pump

Info

Publication number: US3327639A
Application number: US475521A
Authority: US
Inventors: Donald W Sessody
Original assignee: Applied Power Industries Inc
Current assignee: Enerpac Tool Group Corp
Priority date: 1965-07-28
Filing date: 1965-07-28
Publication date: 1967-06-27
Anticipated expiration: 1984-06-27

Description

June 27, 1967 D. w. SESSODY 3,327,639

RECIPROCATING LIQUID PUMP Filed July 28, 1965 T" LL; Ii 1:

4/ 43 I q I II I 46 4 5 24 30312? 20/6/0 6 /2 6' 23 2 INVENTQR. BY 211650100; dugou- 4 W United States Patent Oil ice 3,327,639 Patented June 27, 1967 3,327,639 RECIPROCATING LIQUID PUMP Donald W. Sessody, Milwaukee, Wis., assignor to Applied Power Industries, Inc., West Allis, Wis., a corporation of Wisconsin Filed July 28, 1965, Ser. No. 475,521 8 Claims. (Cl. 103-153) This invention relates to liquid pumps and more particularly to liquid pumps in which radial forces on the pumping plunger due to misalignment or from the actuating handle are minimized and the usual requirements for lubrication of the plunger are eliminated. As such, the pump is suitable for the high pressure pumping of all liquids including water.

As is well known, liquid pumps generally comprise a pump body having inlet and outlet ports with check valves to control the passage of liquid therethrough, The body also includes a bore connected to the ports having a pump plunger reciprocally mounted therein to pump fluid from the inlet port to the outlet port.

' It may be readily appreciated that for most satisfactory operation, the pumping plunger should be axially aligned with the axis of the bore and the force to reciprocate the plunger should be applied only along that axis.

However, pumps of this type are generally actuated by a swingable handle, pivoted to attain the necessary mechanical advantage. The force to reciprocate plunger is therefore applied through at least a short are, asserting radial, as well as axial, reciprocal forces on the pumping plunger for a portion of the stroke, increasing wear between the bore and the pumping plunger or requiring lubrication therebetween, decreasing the pressure which the pump can handle, and disturbing the alignment of the plunger and the bore.

It is an object of the present invention to provide a liquid pump having a means to eliminate radial forces on the pumping plunger therein, thus minimizing wear on the plunger while permitting the use of a swingable actuating handle to reciprocate the plunger.

Another object of the invention is to provide a pump embodying a reciprocal plunger and a swingable actuating handle and which is nevertheless capable of pumping nonlubricating liquids such as water, ether, or alcohol.

A further object of the invention is to provide a liquid pump in which the reciprocating force for the plunger is applied only along the axis of the plunger and bore, thereby permitting close tolerances between the plunger and the bore and reducing the sealing requirements for preventing leakage.

The above and other objects of this invention are attained by providing a pump body having a bore therein, one end of which is connected to inlet and outlet ports. The pumping plunger is mounted in the end of the bore adjacent the inlet and outlet ports. A drive plunger is mounted in the other end of the bore in longitudinal alignment with the pumping plunger. A universal joint connects the pumping plunger and the drive plunger at their adjacent ends. The swingable actuating handle is pivotally mounted on the pump body and is connected to the drive plunger by means of a pin and slot to reciprocate the pumping plunger through the drive plunger and universal joint. The universal joint between the pumping plunger and the drive plunger eliminates any radial forces which might be applied to the pumping plunger by the actuating handle. In the presently preferred embodiment of the invention, the universal joint includes a socket in the end of the drive plunger having a ball therein bearing on a projection of the pumping plunger extending into the socket. Suitable means such as a pin between the socket portion of the drive plunger and the projection of the pumping plunger retains the assembly together.

The invention, together with its features and advantages, may be further understood by reference to the following specification and drawings, forming a part thereof, in which:

FIGURE 1 is a perspective view of a liquid pump of the present invention; and

FIGURE 2 is a longitudinal cross-sectional view through the pump with the actuating handle and attendant parts being shown in plunger retracting position by means of dot-and-dash lines.

Referring now to the drawing, there is shown therein a pump of the present invention indicated by the numeral 2. The pump includes a pump body 4 having an inlet port 6 and an outlet port 8. The inlet port 6 is connected to a reservoir 7 or the like, and the passage of liquid through inlet port 6 and outlet port 8 is controlled by check valves 10 and 12 which permit liquid to flow from the inlet port to the outlet port. Outlet port check valve 12 may be springloaded by compression spring assembly 14. If desired, a pressure gauge 15 may be connected to outlet port 8 by means of fitting 16.

The pump body 4 also contains bore 18 which is connected to inlet port 6 and outlet port 8 at one end thereof. Pumping plunger 20 is mounted in bore 18 and is reciprocal therein to draw liquid from the inlet port 6 and pump it under pressure through outlet port 8. Pumping plunger 20 may be sealed at one end of bore 18 by a O-ring seal 22 or a suitable packing.

In accordance with the invention, a drive plunger 24 is mounted in a bore 25 in longitudinal and axial alignment with pumping plunger 20. Sleeve bearing 26 or the like may also be inserted and retained in bore 25 to provide a bearing for drive plunger 24.

Pumping plunger 20 and drive plunger 24 are connected by a universal joint 29. In the present embodiment, this universal joint 29 includes a socket 28 in the end of drive plunger 24 adjacent pumping plunger 20, ball 30 mounted therein, and projection 32 on the end of pumpin-g plunger 20 extending into socket 28. Socket 28 is in axial alignment with the axis of bore 18 and pumping plunger 20. Ball 30 is likewise aligned with the axis of bore 18 and pumping plunger 20. Projection 32 has a that bearing surface on the end abutting and seated against ball 30. Pin 34, extending through drive plunger 24 and projection 32, holds the joint together.

A swingable actuating handle 36 is connected through a lever arm 38 to pivot 40 in the end of drive plunger 24. The lever arm 38 is pivotally mounted as at 39 to permit the handle 36 to be swung through an arc and pivot 40 may conveniently consist of pin 41 extending through drive plunger 24 and a nut 43 or the like mounted thereon. The lower end of lever arm 38 is bifurcated and contains alined slots 45 in the bifurcations 44 which permit lever arm 38 to slide on pin 41 as handle 36 is swung to translate a reciprocal movement to drive plunger 24. While slots 45 relieve some of the radial forces applied to drive plunger 24, substantial radial forces remain due to the friction between pin 41 and the sides of slots 45 but these are absorbed by the drive plunger 24. For convenience in machining and assembly, lever arm '38 and its pivotal mounting together with the drive plunger and attendant parts are mounted on pump body 4 by bracket 42, and the entire assemblage may be mounted on a base 46 if desired.

To operate pump 2, actuating handle 36 is raised and lowered as shown by the dot-and-dash lines to provide a reciprocating mot-ion to drive plunger 24 through pivot 40. Lowering handle 36 forces drive plunger 24 and pumping plunger 20 into their respective bores 25, 18 for the pumping or displacement stroke of the pump 2. The force applied by lever 'arm '38 to pivot 40 is transmitted through universal joint 29 to pumping plunger 20'. More specifically, the force is transmitted through ball 30 to the bearing surface onthe end of projection 32. The contact between ball 30 and the bearing surface on the end of projection 32 will, of course, be a single point contact and that-point will be on the axis of bore 18. The force transmitted to pumping plunger 20 will, therefore, be applied along the axis of bore 18. Additionally, the force will be applied in an axial direction only and without radial forces since the point contact between ball 30 and the bearing surface on the end of projection 32 is unable to transmit radial forces. Any radial forces imposed on drive plunger 24 by lever arm 38 will be absorbed by that plunger and by the bearing means 26 rather than by pumping plunger 20 and bore 1 8 as in the usual case.

The displacement of liquid by pumping plunger 20,

raises check valve 12 off its seat and passes the liquid to outlet port 8 in a well known manner.

' Raising handle 36 causes drive plunger 24 to withdraw from bore 18, forming the return or suction stroke of pump 2. Pumping plunger 20 is withdrawn by means of pin 34 which is loosely fitted in projection 32 to again prevent the application of radial forces to pumping plunger 20. The suction caused by the withdrawal of pumping plunger 20 causes check valve to lift off its seat allowing liquid to enter bore 18. This action is, of course, repeated as many times as is necessary to pump the desired quantity of liquid.

It will be apparent that various modifications and substitutions in the above described embodiment of the present invention may be made without departing from the principles of invention or the scope of the appended claims. It should furthermore be understood that the liquid supply for the pump may be drawn from any suitable source and not necessarily from the reservoir 7, and that the gauge may or may not be employed.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1. A pump comprising, a body provided with valvecontrolled inlet and outlet ports communicating with a bore in said body, a pump plunger reciprocal within the bore to pump fluid from the inlet to the outlet port, a drive plunger supported for reciprocal movement in axial alignment with said pump plunger, one of said plungers being formed with an end socket, a ball seated within the socket of said one plunger, a projection on the other of said plungers extending into the socket adjacent said ball, means for retaining said projection in the socket to connect said plungers, and means for reciprocating said drive plunger to thereby drive said pump plunger through said connection, whereby radial forces exerted are absorbed by said drive plunger.

2. A pump according to claim 1, wherein the socket is formed in the end of the drive plunger and the projection is formed on the end of the pump plunger.

3. A pump according to claim 1, wherein the projection on the plunger is formed with a flat end surface which bears on the ball.

4. A pump according to claim 1, wherein the means for retaining the projection in the socket is a pin which extends through the wall of the plunger formed with the socket and through the projection formed on the other plunger.

5. A pump according to claim 1, wherein the means for reciprocating the drive plunger is an actuating handle mounted for swinging movement and connected to the drive plunger through a pin and slot connection.

6. A pump according to claim 1, wherein the drive plunger is mounted in a separable extension of the pump body.

7. A pump according to claim 6, wherein the separable extension is removable as a unit with the drive plunger and includes a bearing surrounding the drive plunger.

8. A pump according to claim 7, wherein the means for reciprocating the drive plunger is an actuating handle mounted on the separable extension for swinging movement and connected to the drive plunger for transmitting reciprocal movement thereto.

References Cited UNITED STATES PATENTS 1,551,324 8/1925 Offerdahl 92-491 1,713,906 5/1929 Lake 103 153 2,644,731 7/1953 Doeg ,92 -191 2,771,845 11/1956 Eagan 10=3 153 2,818,314 12/1957 Nicholas 92-487 3,173,344 3/1965 Mongitore 92l87 FOREIGN PATENTS 562,820 7/1944 Great Britain.

335,905 2/1936 Italy.

ROBERT M. WALKER, Primary Examiner.

HENRY F. RADUAZO, Examiner.