US1958509A

US1958509A - Diaphragm pump

Info

Publication number: US1958509A
Application number: US657358A
Authority: US
Inventors: William C Carter
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-02-18
Filing date: 1933-02-18
Publication date: 1934-05-15
Anticipated expiration: 1951-05-15

Description

`Mmyls, 1934. w, CARTER 1,958,509

DIAPHRAGM PUMP Filed Feb. 18, 1953 H .I FIGLI i H l ,l

)I B D p V22;. A J

j z 3 K @a D F c 2 .f jg.. a /0 L2\ ,ffl L `9 f3 FIGZ gurl I I/vve/vToR WILLIAM C. CARTER Patented May l5, i193@ UNET f 2 Claims.

This invention relates to diaphragm pumps of re kind that are used for pumping a liquid from a source of supply to a consumption device in which the consumption of liquid from the pump is irregular, and upon the complete interruption of the consumption of liquid by said device, a pressure is created which is exerted on the diaphragm of the pump in opposition to the means that imparts a discharge stroke or power stroke to the pump diaphragm.

I have herein illustrated my invention embodied in a fuel pump that is intended to be used for feeding gasoline or the like from a supply tank to the float chamber of the carburetor of an internal combustion engine, and which is equipped with a diaphragm operating mechanism that comprises a cam or other prime mover and a member or element acted upon by said prime mover and arranged to actuate or impart movement to the diaphragm or to a part of the diaphragm operating mechanism that acts directly on the diaphragm. I wish it to be understood, however, that my invention is not limited to a diaphragm pump that is designed particularly for pumping gasoline or the like; also that variou's changes can be made in the construction of the diaphragm operating mechanism herein described without departing from the spirit of my invention.

One object of my present invention is to provide a practicable diaphragm pump of the general type or kind previously referred to, wherein the member or element operated on by the prime mover, is of such design or construction that it is not necessary to directly actuate the diaphragm by a spring, or interpose a spring between the diaphragm and the member or element that is operated on by the prime mover, thereby producing a pump in which the pressure or power pro duced by the diaphragm is constant or uniform throughout the entire stroke of the diaphragm when the diaphragm is in normal operation.

Another object of my invention is to provide a diaphragm pump that is equipped with an inexpensive diaphragm operating mechanism which is of such design or construction that the pump can be easily combined with or installed on an internal combustion engine or other apparatus equipped with a prime mover that constitutes part ofthe diaphragm operating mechanism of the pump.

Other objects and desirable features of my invention will be hereinafter pointed out.

Figure l of the drawing is a vertical longitudinal sectional View of a diaphragm fuel pump constructed in accordance with my present invention; and

Figure 2 is a horizontal sectional view, taken on the line 2--2 of Figure 1.

In the accompanying drawing which illustrates (Ci. 10S-38) the preferred form of my invention, A designates the diaphragm of the pump, which is preferably composed of either one or a plurality of layers of fabric treated with a substance that will render the fabric impervious to gasoline or water, without making it brittle or inflexible, which diaphragm may be disposed either vertically or horizontally. The diaphragm A is arranged `so as to form one wall of a pumping chamber into which liquid fuel is drawn when said diaphragm flexes in one direction, and from which said fuel is discharged when said diaphragm iiexes in the opposite direction, the said pumping chamber being formed by a cavity in a casting B that constitutes the body portion of the pump and which is supported by a housing member C that is herein illustrated as being attached to the crank case D of an internal combustion engine. An inlet pipe E that leads from a source of supply of fuel delivers fuel to a fuel reservoir F in the body portion B of the pump, and a discharge pipe G that is attached to said body portion leads to the float chamber of a carburetor (not shown). An inlet valve H is provided for admitting fuel to the pumping chamber a: from the fuel reservoir F, and a discharge valve I is provided for governing the escape or passage of the fuel from the pumping chamber :c into the discharge pipe G.

The operating mechanism for the diaphragm A comprises a prime mover J, such, for example, as a cam arranged inside of the crank case D of the engine, a spindle or other part K attached in any suitable or preferred manner to the center of the diaphragm, and an element or member designated as an entirety by the reference character L in Figure l, arranged between the prime mover J and the spindle K for reciprocating said spindle, so as to move the diaphragm A back and forth. In the form of my invention herein illustrated the element L consists of a lever rockably mounted or pivotally mounted on a horizontally-disposed pin or shaft 1 in the housing member C, and provided at one end with a bifurcated portion 2 that is embraced by anges 3 on the spindle K. The'other end portion of said lever L projects inwardly through an opening in the crank case, as shown in pigure 1, and is provided with a fork or yoke 4 that receives the cam J which constitutes the prime mover of the diaphragm operating mechanism.

When the engine is in operation there are times when the discharge valve I ef the pump will remain closed while the prime mover J of the diaphragm operating mechanism continues in operation, as, for example,` when the float chamber of .the carburetor is full, and the head or column of fuel in the discharge pipe G of the pump exerts sufficient back pressure on the discharge valve I to preventl it from being unseated by the pressure in the pumping chamber In order that the diaphragm A may remain at rest at-such times, or, in other words, in order that said diaphragm and the diaphragm operating mechanism will not be subjected to injurious strains when the consumption device with which the pump is used is not consuming or drawing' fuel from kthe pump, the rockable element or lever L- is so constructed that under certain conditions one part of said rockable element, i. e., the right hand part that is associated with the prime mover J, will rock on the fulcrum pin 1 without imparting movement to the left hand part of said rockable member L that is attached to the spindle K on the diaphragm. This resultor effect can be obtained in various ways without departing from the spirit of my invention, but I prefer to construct the lever or element L from two sections'L' and L2 that are rockably mounted on the supporting shaft or pivot pin 1, and join or connect said sections L and L2 together by a friction joint which is of such a character or nature that under certain conditions said two sections will rock together or move in unison, and under other conditions or different conditions thesection-L actuated by the prime mover J can move independently of and relatively to the section L2. As shown in Figure 2. the section L' is provided at its inner end .with

a disk shaped portion 5 `through which the suptogether with suflicient force or pressure to causev the section L2 to normally move with the section L and co-operate with same to form a lever that is pivotally supported intermediate its ends. In the pump herein illustrated the springs 8 are formed by substantially disk-shaped resilient members provided with spring fingers 8a that exert an inward thrust on the disk-shaped portions 7 of the section L2 which said springs 8 embrace, the said springs 8 being mounted on the supporting shaft 1 between the disk-shaped portions 7 of the section L2 and parallel wall portions 9 on the housing member C.

In order that the section L2 of the rockably element L will be sure to rock or move with the positively actuated section L -when the element L rocks in a direction to impart a suction stroke (downward stroke) to the diaphragm A, but will be free to'lag or stop when the element L rocks in the reverse direction to impart a discharge stroke (upward stroke) to the diaphragm if the discharge of fuel from the pumping chamber a: is interrupted, a contractile spring M is attached to the sections L and L2 in such a manner that when the section L rocks upwardly (looking at Figure 1 the spring M will exert pressure on the section L2 ina direction tending to cause the friction joint to exert more pull on the diaphragm, as is necessary on the suction stroke, and when the section L rocks downwardly or in the reverse direction, said spring M will cause the friction'joint to exert less upwand push on the diaphragm, as is necessary on the discharge stroke. In other words, there should be a pressure of approximately four to six pounds bringing the liquid into the pumping chamber and only a pressure of approximately one to two pounds forcing the liquid out of the pumping chamber. Accordingly, what the spring M subtracts from the discharge pressure it adds to the suction stroke. I have herein illustrated the spring M as being attached at one end to a lug 10 on the outer section L of the rockable element L, and being attached at its opposite end to a cross pin 1l carried by lugs 12 on the inner section L2 of the rockable element L. As previously explained,

when the pump is in normal operation, i. e., when the carburetor is drawing iuel from the pump, the two sections L and L2 of the rockable member L move in unison, but if the discharge of fuel from the pumping chamber :l: is interrupted, the section L2 is capable of coming to rest while the section L continues in operation, due to the friction joint or friction connection between said sections. In this way I overcome the objections incident to the use of a spring to directly actuate the diaphragm of the pump, without, however, imparting a positive stroke to the diaphragm, and I produce a pump in which the force or pressure created by the diaphragm is maintained practically constant throughout the entire discharge stroke of the diaphragm. In addition to accomplishing the highlyl desirable result previously described, the friction joint of the rockable element L facilitates the installation of the pump on an internal combustion engine or other apparatus provided with a cam or the like that constitutes the prime mover of the diaphragm operating mechanism, due to the fact that saidv lfriction joint permits the two sections of 'the rockable element L to move sufficiently relatively to each other to cause the outer section L' to adapt itself to the prime mover J, even though there is a slight mal-alignment between the prime mover and the housing member C on which the rockable element L is mounted.

Having thus described my invention, what I claim as new and desire to secure byLetters Patent is:

l. A diaphragm pump provided with a diaphragm for causing liquid to be drawn into and discharged from a pumping chamber, aprime mover and a lever for transmitting movement from said prime mover to said diaphragm, said lever comprising two sections provided with overlapping portions through which the fulcrum of the lever passes, means for frictionally connectingsaid overlapping portions, and a spring that co-acts with said sections for increasing the tendency of said sections to move in unison during the suction stroke of the diaphragm, and to permitv relative movement between said sections during the discharge stroke of the diaphragm.

2. A diaphragm pump provided with a diaphragm for causing liquid to be drawn into and discharged from a pumping chamber, a spindle attached to said diaphragm, a prime mover, a housing lor supporting member, a lever pivotally mountedV on said housing and provided with two .-relativelymovable rockable sections, one of which is joined to said spindle and the other arranged in engagement with said prime mover, a friction means for transmitting movement from the prime mover section to the spindle section, and a spring combined with said sections for exerting a pull on said spindle section in a direction tending to causeit to move with the prime mover section, during the suction str oke of' the diaphragm.

WILLIAM C. CARTER.