US2735373A - Means for priming the liquid circuit of - Google Patents

Description

Feb. 21. 1956 c s. LE CLAIR 2,735,373

C. MEANS FOR PRIMING THE LIQUID CIRCUIT OF RECIPROCATING PUMPS FOR LIQUID OR OIL Filed Dec. 28, 1951 2 SheetsShee1 l Inventor.-

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Feb. 21. 1956 C. C. MEANS FOR PRIMI NG' THE LIQUID CIRCUIT OF RECIPROCATING PUMPS FOR LIQUID OR OIL Filed Dec. 28, 195] 4O 44 "134 43 4/ --aa /4 J3 I mam-m 2 Sheets-Sheet 2 Inventor.-

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United States Patent ANS FOR PRIMING THE LIQUID CIRCUIT OF RECIPROCATING PUMPS FOR LIQUID OR OIL Crabtree, Plymouth,

Camille Clare Sprankling Le Clair,

Limited, Brentford,

England, assignor to Tecalemit England This invention relates to pumps of the type comprising pistons or plungers which are reciprocable in pump cylinders and are adapted to control the opening and closing of inlet ports and to eject liquid from the cylinders on their discharge strokes.

The invention is particularly adapted for use with small capacity pumps of the kind described in my prior United States Patent No. 2,371,054 of March 6, 1945. Such a pump comprises a plunger and an opposed piston both of which are reciprocable in the same cylinder bore. The plunger is reciprocated by a driving member and is arranged to control the opening and closing of an inlet port. The piston controls the opening and closing of-an outlet port and is acted upon by a light spring, which act-s to impose a slight pressure difference between the entrapped liquid and the inlet supply, and also by a heavier spring which resiststhe outward movement of the piston on the discharge stroke of the plunger and thus imposes a pressure in the cylinder which is equal to, or greater than, the discharge pressure against which the pump is working.

The outer end of the piston and the light spring are enclosed in a head which is slidably arranged in an adjustable cap, and the heavy spring reacts between the head and shoulder in the cap. The pump output can be varied While the pump is working by adjusting the cap and thus the position of the piston in relation to the outlet port.

The object of the present invention is to provide means whereby the liquid circuit connected to the outlet of a pump of the type referred to may: be primed manually even while the pump driving means is still running. This enables one to ensurethat the system shall be fully charged and thus obviate the time lag in delivery consequent upon an incompletely charged system.

According to the present invention a pump of the type referred to is characterised by the feature that it includes means for priming the liquid circuit connected to the outlet of the pump which means is adapted to disconnect the pump plunger from the driving mechanism, fromflwhich mechanism the movement of the plunger is normally derived, while allowing the plunger to be reciprocated without interrupting the movement of the driving mechanism. Thus, the plunger may be freed from its driving-mechanism and, moreover, it can be reciprocated manually or otherwise when thus freed.

The said means is preferably manually-operable and may comprise a movable latch or catch device which when in its inoperative position acts to connect the said driving mechanism to the plunger so that the latter is mechanically reciprocated, but which when in its operative position acts to render the said mechanism inoperative to drive the plunger, but allows the plunger to be'reciprocated manually while the said mechanism is still in motion.

The plunger-driving mechanism may include a pivoted link which is connected to the plunger, a pivoted rocker, and a latch or catch device which is arranged on, and movable with, a reciprocable and turnable priming rod, and is adapted to provide a connection between the link and rocker. The arrangement is such that when the rod is turned into one angular position the latch or catch device acts to form a connection between the rod, the link and the rocker, whereas when the rod is turned into a second angular position only the connection with the rocker is broken so that the plunger may be reciprocated by reciprocating the priming rod while the then disengaged rocker continues to oscillate idly.

In one constructional form of the invention, the latch is in the form of a disc provided on a priming rod which is slidable and turnable in a guiding bore in the pump body, the disc being so shaped that when the priming rod is in its inoperative position a portion of the disc engages in slots formed in the link and the rocker, whereas When the rod is turned into its operative position the disc disengages the slot in the rocker but still engages the slot in the link. Thus, when the priming rod is reciprocated the plunger is also reciprocated while the rocker continues to oscillate without aifecting the plunger. It will be appreciated, of course, that the priming rod may also be reciprocated while the rocker is stationary.

It is preferred to employ means for pulling the priming rod into its position in which the latch acts to connect the rocker to the plunger-driving link. Such means conveniently consists of one or more springs connected to the priming rod at one end and to an anchorage at the 0pposite end.

One constructional form of the invention, applied to an oil pump of the type described in my said prior Patent No. 2,371,054, will not be described, by way of example, with reference to the accompanying drawings, wherein- Fig. 1 is an outside elevation of the pump;

Fig. 2 is a transverse section through the plunger-operating mechanism and the priming rod; and

Fig. 3 is a sectional elevation of the pump.

Referring to the drawings:

The pump comprises a body part 1 which is formed with a cylinder bore 2 in which an 4 are slidable. One end of the piston projects out of one end of the cylinder bore and one end of the plunger projects out of the opposite end of the bore. The piston is provided with a sealing ring 5 to prevent leakage of oil from the cylinder bore and the plunger is provided with grooves 6 which act as labyrinth seals. The protruding end of the piston 3 is arranged in a cap 7 which is adjustably threaded into a counterbore 8 in the body forming an enlargement of the cylinder bore. The output of the pump can be varied while the pump is working by adjusting the threaded cap 7 and thereby changing the position of the piston 3 in relation to the outlet port 19. As'in the case of the pump described in the said prior specification, the outer reduced end of the piston is arranged in a head 9 and the piston is held under slight initial pressure by means of a light spring 10 which reacts between the end of the head and a shoulder 11 on the piston. The light spring 10 imposes a slight pressure difference be tween the entrapped liquid and the inlet supply. The head 9 is slidably arranged within the cap and a heavy spring 12 surrounds the head and reacts between the latter and the end of the cap. The heavy spring 12 imposes a pressure in the cylinder which is equal to, or greater than, the discharge pressure against which the pump is working.

The protruding end'of the plunger 4 is connected by means of a transverse pin 13 to a link member 14 which is pivotally mounted upon a pin 15'supported in two spaced brackets 16 which are integral with the pump body. The ends of the pin 13 engage in slots 13a in the link member. The pump body is provided with an oil inlet passage 17 which is connected to the oil supply (not shown) andthe inner end of which communicates with a port 18 leading into the cylinder bore. Thus, as the plunger reciprocates it first opens the inlet port, and then closes it on its disopposed piston 3 and plungercharge stroke. An outlet port 19, which is spaced axially from the inlet port, is connected to a J-shaped small bore outlet tube 20, the upper end of the longer limb of which is supported in a disc pad 21 fitted in a recess 22 formed in the body below the cylinder here. The lower end of a fine-gauge wire rod 23 is mounted in the open end of the shorter limb of the outlet tube 20, the upper end of the Wire rod passing through the disc pad 21 and being engaged in the lower end of a recess 24 communicating With a passage 24a which extends upwards through the body and terminates in an outlet chamber 25 into which a valvecontrolled outlet union 26 supporting a discharge pipe 27 is screwed.

The J-shaped outlet tube 20 and the wire rod 23 are enclosed in a glass bowl 28 which is detachably held in a recess 28a connected to the above mentioned recess 22 in the pump body between a sealing ring 29 and a sleeve 30 which is screwed into the first mentioned recess. The outlet tube and the wire rod from a rising drop indicator. The bowl is filled with water or a solution of glycerine and water or other filling agents and the wire rod provides means for the ascent of drops of oil in the solution, the drops, of course, being observable through the bowl. The glass bowl may be removed for cleaning and for servicing of the rising drop indicator.

A rocker arm 31 is pivotally mounted upon the above mentioned pin 15 upon which the link 14 is also pivotally mounted. The rocker arm is of substantially C-shape and its curved upper limb 31a is arranged in the upper forked end of the link. The limb 31a and the forked end of the link are formed respectively with transverse slots 32 and 33 for a purpose described hereinafter.

A priming rod 34 is slidably mounted in a cylindrical guide 35 which is parallel to and above the cylinder bore 2. Both ends of the priming rod protrude from the guide and one end is provided with a handle 36. On a pin 37 fixed near to the opposite end of the rod 34 is connected the upper end of a spring 38, the lower end of which is connected to an anchor pin (not shown). Thus, the spring tends constantly to turn the priming rod in the clockwise direction, as viewed from the rocker arm end of the pump, i. e., in Fig. 2. Between the end of the priming rod to which the spring 38 is attached and the adjacent wall of the pump body a latch member in the form of a disc 40 is fixed on, or is integral with, the rod. Part of the periphery of the latch disc is cut away so as to provide a segmental portion 41, Fig. 2, which is adapted to engage in the said slots 32 and 33 in the upper limb of the rocker arm and the forked end of the link respectively. As mentioned above, the spring 38 associated with the priming rod pulls the latter clockwise as viewed from the rocker arm end of the pump. The angular movement of the rod in this direction is normally stopped by a shoulder 42 on the latch which borders one side of the said segmental portion 41 and which abuts against one side of the link 14. On the opposite side of the segmental portion there is a recess 43 which is wide and deep enough to allow the rocker arm to oscillate in it. Adjacent to the recess there is another shoulder 44 which is adapted to abut against the opposite side of the link, thus preventing further movement of the priming rod and the latch disc in the anti-clockwise direction.

In the normal operation of the pump the segmental portion 41 of the latch disc engages in the slot 32 in the upper limb 31a of the rocker and the slot 33 in the forked end of the link and thus operatively connects the rocker, the link and the plunger. When the priming rod 34 is turned in the anti-clockwise direction against the action of its spring 38 the recess 43 in the latch disc spans the upper limb of the rocker, which latter can thus continue to oscillate. The portions of the latch disc on opposite sides of the said recess 43, however, engage in the transverse slots 33 in the link 14 and if the priming rod is reciprocated the link isoscillated and the plunger 4 is reciprocated while the rocker continues to oscillate idly. When the priming rod is released its spring 38 turns it back into its inoperative position in which the latch disc again provides an operative connection between the rocker arm and the link.

There are many ways of oscillating the rocker arm. As one example, which is shown in Figs. 1 and 3, the arm may be provided with a fork 44 in which an eccentric (not shown) mounted upon a driving shaft is engaged, the arrangement being such that the revolving eccentric acts to oscillate the rocker about its pivoted support 15.

The above mentioned glass bowl may be removed while the rocker continues to oscillate idly and the connection between the pump plunger and the link is disengaged.

I claim:

1. A pump of the class described comprising a body provided with a bore having an inlet and an outlet and forming a pump cylinder, a plunger slidably mounted in said bore and adapted to force fluid through said outlet, a pivoted link mounted on said body and connected to said plunger and having in its free end a slot transverse to the path of movement of said link, a driving mechanism including a pivoted rocker mounted on said body and adapted to engage said link, said rocker having a slot in its free end transverse to the path of movement of said rocker, a manually operable priming rod for driving said link, said rod being reciprocable and turnable in a second bore in the pump body, and a disc secured to said priming rod whereby in one angular position of said rod one portion of said disc engages the slots of the rocker arm and link, and in a second angular position of said rod another portion ofv said disc engages said link but provides a notch in the path of movement of said rocker to permit operation of the plunger by said priming rod without interrupting the movement of the pivoted rocker.

2. A pump of the class described comprising a body provided with a bore having an inlet and an outlet and forming a pump cylinder, a plunger slidably mounted in said bore and adapted to force fluid through said outlet, a pivoted link mounted on said body and connected to said plunger and having in its free end a slot transverse to the path of movement of said link, a driving mechanism including a pivoted rocker mounted on said body and adapted to engage said link, said rocker having a slot in its free end transverse to the path of movement of said rocker, a manually operable priming rod for driving said link, said rod being reciprocable and turnable in a second bore in the pump body, yieldable means anchored to said body and retaining said priming rod in a given angular position, and a disc secured to said priming rod and having a porton engaging the slots of the rocker arm and link when said priming rod is held in normal angular position by said yieldable means, said disc having a second portion including a notch in the path of movement of said rocker arm when said priming rod is turned to a difierent angular position to permit operation of said plunger by said priming rod without interfering with the movement of said rocker arm.

3. In a pump having separate priming means and driving means adapted for connection to a motion transmit ting means mounted for movement relative to said pump and connected to a plunger reciprocable in a pumping chamber formed in said pump for reciprocating the same; a driving connection movable relative to a motion transmitting means between a first position wherein it connects said driving means to said motion transmitting means and a second position wherein it frees said driving means for independent movement and connects said priming means to said motion transmitting means.

4. In a pump having separate priming means and driving means adapted for connection to a motion transmitting means mounted for movement relative to said pump and connected to a plunger reciprocable in a pumping chamber formed in said pump for reciprocating the same; a driving connection movable relative to a motion transmitting means between a first position wherein it connects 5 said driving means to said motion transmitting means and a second position wherein it frees said driving means for independent movement and connects said priming means to said motion transmitting means, and yieldable means biasing said connection in said first position.

5. In a pump having separate priming means and driving means for actuating a plunger that is reciprocable in a pumping chamber formed therein; motion transmitting means mounted for movement relative to said pump and connected to a plunger for reciprocating the same, said motion transmitting means including a driving connection movable relative to said motion transmitting means between a first position wherein it connects said driving means to said motion transmitting means and a second position wherein it frees said driving means for independent movement and connects said priming means to said motion transmitting means.

6. In a pump having separate priming and driving means adapted for connection to a motion transmitting means mounted for movement relative to said pump and connected to a plunger reciprocable in a pumping chamber formed in said pump for reciprocating the same; the improvement wherein said priming means includes a rod rotatably and reciprocably mounted in a bore in said pump and supports connecting means for movement relative to a motion transmitting means by rotation of said rod between a first position wherein saidconnecting means connects said driving means to said motion transmitting means and a second position wherein said connecting means frees said driving means for independent movement and connects said priming means to said motion transmitting means.

References Cited in the file of this patent UNITED STATES PATENTS 1,143,325 Sherman June 15, 1915 1,881,847 Morse Oct. 11, 1932 1,942,549 Hampton Jan. 9, 1934 2,042,004 Hurst May 26, 1936 2,195,037 Pretty Mar. 26, 1940

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