US1742746A - Variable-stroke fuel pump - Google Patents

Description

Jan. 7, 193() J. ZUBATY VARIABLE STROKE FUEL PUMP Filed June 22, 1928 Patented Jan. 7, 1930 UNITED STATES PATENT OFFICE JOSEPH ZUBATY, OF FLINT, MICHIGAN, ASSIGNOR T C SPARK` PLUGv COMPANY, OF

FLINT,`MICHIGAN, A COMPANY OF MICHIGAN VARIABLE-STROKE FUEL PUMP Application led J'une 22,

This invention relates to variable stroke fuel pumps suitable for use upon automotive vehicles, or elsewhere in connection with internal combustion engines or the like; and

it is a particular object of this invention, in

a preferred embodiment thereof, dispensing with an linkage or similar thrust-refusing interme 'ate means for the transmission of motion from an oscillatory lever, or the like, to a pumping element, to provide a novel and conditionall rigid lever or rocker arm, suitable for use between a reciprocatory or rotating part and a pump diaphragm stem,'o1-

the likesaid lever comprising a conditionally resilient arm or section which includes a part that may so constantly engage said reciprocatory or rotating part (as,.an engine crankshaft) as substantially to avoid Contact noises.

Although the present invention is herein described with particular reference to adiaphragm pump similar to that described and claimed 1n a pending application of Abraham M. Babitch, Serial No. 123,370, led July 19, 1926, it should be understood that the principles of this invention are believed to be applicable to other reciprocatory pumps in which provision is made for the use of resilient means to effect expulsion strokes, the intake strokes thereof being variable in length and being eected through the mentioned resilient arm or a like part and being diminished in length as pressure is built up within a pum chamber; and it is a particular object of t is invention to provide pump operatin means which may not only obviate avoi able noises, such as are incidental to the operation of known types of thrust-refusing intermediate mechanism, but also substantially obviate all necessity for any rocking of the mentioned lever, or its equivalent, after a sufficient pressure has been built up withina pump chamber.

Other objects of this invention, most or all forms of which may involve the use of a lever or a rocking or other reciprocatory member which becomes increasingly iniiexible as increased pressures are applied to an initially resilient part thereof, may be best appreciated from the following description 1928. Serial No. 287.625.

of an illustrative embodiment of said invention, taken in connection with the appended claims and the accompanying drawings.

Fig. 1 may be referred to as a substantially median section through one fuel pump illustrative of this invention.

Fig. 2 is a partial view corresponding to the lower portion of Fig. 1, but showing a condition and relationship of parts that may result from the building up of a pressure within a pump chamber.

Referring first to conventional parts of the fuel pump selected for purposes of illustration, a main structural element in the form of a body casting 1 and a subsidiary element in the.v form lof a cover casting 2 are shown as cooperating in the retention of a flexible diaphragm 3,-adapted to serve as a reciprocatory pumping element by varying the cubic contents of a pump chamber 4. This chamber is shown as provided. in the cover casting 2, and said cover casting may be provided with a valved inlet passage 5 and an outlet passage 5', shown as valved at 6. Resilient means in the form of a compression spring 7 may tend constantly to efect expulsion strokes of the diaphragm 3; and intake strokes ma be imparted theretothrough a flexible or in exible but substantially, inex-` tensible tension-transmitting element such as a slidable rod or so-called diaphragm stem 8,-which may be rigidlyconnected with the diaphragm 3 or other reciprocatory pumping element `by means such as a nut 9 and oppositely concave clamping elements or plates 10 and 10.

A cam 11 upon a shaft 12 (which may be, for example, acrankshaft, or a camshaft. or the like) is intended as representative of any reciprocating or rotating vpart having a suitable throw, whether uniform or variable, indirectly to impart reciprocatory movement to the rod or stem 8; andthe present inven tion should be understood to relate Ipar ticularly to the structure and use of anovel actuating element, (shown as an oscillatory lever 13 comprising a resilient part) and a member, such as the rod or stem 8, attached to a reciprocable but pressure-responsive pumping element. For example, the actuating lever 13, shown as pivoted at 14 to the casting 1, may comprise a rigid inner arm 15 and a composite outer arm 16. A inand-slot connection being indicated at 17, the outer and composite arm 16 is shown as comprising a rigid part 18 and a flexible part including a leaf spring 19, optionally j, provided with a contact shoe 20,-the result chamber y a depressed eing a lever which is substantially rigid under certain conditions and notably resilient under other conditions.

As best indicated in Fig. 2, the resilient part 19, or its equivalent, is intended, in the illusg I tratedembodiment of the present invention,

to `be sc biased toward an angular relationshi to the longitudinal axis of the arm 15, that, the leaf 19 being adapted to serve as a spring finger, the contact shoe 20, if employed, may constantly engage the cam 11,-even at times when .a pressure built up within the pump 4 may hold the rod or stem 8 in such position as to render the rotation of cam 11 temporarily ineffective to impart k"further reciprocatory movement thereto.

his construction obviates contact noises and unless the part 18, assumed to be substan- `tially rigid, is of such length as finally to be completely contacted or pressed upon by the free end ofthe spring linger 19 (as, when the 30,

longitudinal axis of the latter is brought into substantial parallelism with the longitudinal axis of the arm 15) in order to render the composite arm 16 substantially unyielding and highly efficient for a pumping eli'ect during those periods of normal operation in the reciprocatory pumping element 3 is desired to receive a full stroke (the presv sure within the chamber 4 being -then insuflicient to hold said pumping element depressed) additional bent and stepped leaf springs or spring sections may be interposed, as suggested by 21, 22 and 23, between the mentioned spring 19 and the rigid part 18,- means such as rivets 24 being employed to hold the mentioned parts in their intended relationship.

It will be understood that, even if rigidly attached to a reciprocatory pumping element, the rod or stem 8 need not be restricted to rectilinear sliding casion use of a pin-andslot connection with the lever 13; but the spring 7, or equivalent resilient means for effecting expulsion strokes, is intended in all cases to be of sufficient strength to overcome the conditional resiliency of the arm 16, or its equivalent,-mov ing the flexible parts thereof into such a relationship that, as by reason of actual contact between the respective leaves 19,21, 22 and 23, said composite arms may function as if rigid, a-nd substantially as implied by the movement such as to ocactuating element 13 (assuming this to be a lever) may be moved toward and kept in such a depressed position as to result in a separation of some or'all of the leaves 19, 21, 22, but without causing a se aration of the contact shoe 20, if employed, om the cam 11. As soon as the pressure within the chamber 4 drops, it will be understood that some or all of the spring leaves 19, 21, 22 and 23 may again be brought into mutual contact; and the composite arm 16 may again function as if rigid, substantially as suggested in Fig. 1.

It will be noted that, so far as concerns the described mode of operation, either or both of the arms 15, 16 ofthe actuating element 13, assuming the latter to have the form of a lever, may be composite and conditionally rigid, increasing in rigidity under increasing upward ressure at the free end or ends thereof; t at the use of separate spring leaves, bent to different angular relationships to the axis of the rigid arm 15`and varying in length is essentially a preferred mode of providing a slap-preventing spring finger 19, or its equivalent, with graduated reinforcement; that contact shoe 20, if provided, may or may not be integral with the spring linger 19; and that all embodiments of this invention have, as compared with the usual collapsible linkage systems, or the like, the advantage that they require only one pivotally movable member and but few additional parts, these being compactly arranged, no separate'spring being needed beneath the lever 13, and both strokes of the described pump being eifected by or through resilient means.

Although the forefgoing description includes a description o but one complete embodiment of the present invention, -it should be understood that numerous modifications of this invention might easily be devised, without involving the slightest departure from the spirit and scope of this invention.

I claim:

1. In a fuel pump comprising a recipro catory pumping element which is provided with resilient means for conditionally effecting expulsion strokes thereof: a tensiontransmitting element attached to said umping element; and an actuating lever a apted normally to impart intake strokes to said attached element, said actuating lever comprising a resilient part so rein orced as to increase in ri 'dty under pressure.

2. In a uel pump comprising a reciprocatory pumping element which is provided with resilient means for conditionally effecting expulsion strokes thereof a tension-transmitting element attached to said pumping element; and an actuating lever adapted normally to impart intake strokes to said attached element, said actuating lever comprising a resilient part which increases in rigidit under pressure, and becomes substantia lfylrigid in normal pumping operation.

3. A el pump comprising: a reciprocable pumping element provided with resilient 5 means for e'ecting expulsion strokes thereof and with an attached handling element; and an actuating lever, for said handlin element, comprislng a spring finger adapted constantly to en age a moving part and provided with gra uated reinforcmg means to increase the rigidity thereof upon the :application of increasing pressures thereto.

4. A fuel pump comprising: a reciprocable pumping 'element provided with resilient means for effecting expulsion strokes thereof and with an attached handlin element; and an actuating element, for sai handling element, comprising a spring finger adapted constantly to engage a moving part and 2o provided with graduated reinforcing means to increase the rigidity thereof upon the application of increasing pressures thereto,- said actuating element having the form of a lever provided with a substantially rigid arm which is pivotall connected with said handling element an also with a composite arm which includes said spring finger.

5. A fuel ump comprising: a reciprocable pumping e ement provided with resilient $0 means for effecting expulsion strokes thereof and with an attached handlin element; and an actuating element, for sai handlin element, comprising a spring finger adapte constantly to en age a moving part and provided'with graduated reinforclng means to increase the rigidity thereof upon the application of increasing pressures thereto,-said actuatin element havin the form of a lever rovide with a substantially rigid arm which 1s pivotally connected not only with said handlin element but also with a composite arm whic includes said spring finger and also includes a stepped series of leaves bent toV different angular relationships to the rigid arm and constituting said gra uated reinforcing means.

6. A pump comprising: a reciprocable pumpin element having a handling element attache thereto; and a lever comprising a 5o conditionally resilient arm and operatively connected with said handlin element.

In testimony whereof I a my signature.

JOSEPH ZUBATY.

Images