US3306212A - Pump with adjustable speed and stroke - Google Patents

Description

Feb. 28, 1967 s. H. NORTON PUMP WITH ADJUSTABLE SPEED AND STROKE 4 Sheets-Sheet 1 Filed July 27, 1964 K8 Q s) INVENTOR.

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A'T'TO EYS Feb 28, 1967 s. H. NORTON 3,306,212

PUMP WITH ADJUSTABLE SPEED AND STROKE Filed July 27, 1964 4 Sheets-Sheet 4 trite Etat 3,366,212 PUMP WITH ADJUSTABLE SPEED AND STROKE Samuel H. Norton, University Heights, Ohio, assignor to TRW Inc, a corporation of Ohio Filed .Iuiy 27, 1964, Ser. No. 385,237 12 Claims. (Ci. 1t)338) This invention relates generally to pumping mechanisms and more particularly to a two cylinder pump with adjustable speed and stroke wherein suction and compression strokes can be maintained in a predetermined proportion of duration.

It is an object of the present invention to provide a piston-type pump characterized by means for adjusting and varying the duration and length of the suction and compression strokes.

Another object of the present invention is to provide means for adjusting the strokes in a piston-type pump wherein the piston will always travel through the complete length of a stroke to the cylinder head regardless of the length of either the suction stroke or the compression stroke.

Yet another object of the present invention is to provide means for venting the cylinders of a piston-type pump to the atmosphere at the end of each suction stroke in order to equalize the pressure or vacuum in the cylinders after adjusting the strokes.

A still further object of the present invention is to provide adjustment means affording a micrometer adjustment of the length of the piston strokes.

A still further object of the present invention is to provide clamping means and calibration means whereby the length of the piston strokes may be selectively adjusted and locked in such selected adjustment and wherein special calibrated means for provided for indicating the 7 amount of adjustment with particular reference to the length or speed of the strokes.

Another object of the present invention is to provide a piston-type pumping mechanism with means for venting the crank housings to the atmosphere.

Many other features, advantages and additional objects of the present invention will become manifest to those versed in the art upon making reference to the detailed description which follows and the accompanying sheets of drawings in which a preferred embodiment of a pumping mechanism incorporating the principles of the present invention is shown by way of illustrative example,

On the drawings:

FIGURE 1 is a crosssectional view of a pump provided in accordance with the principles of the present invention taken generally on line I-I of FIGURE 2;

FIGURE 2 is a cross-sectional view taken through one of the pumping units in the plane of line IIII of FIG- U FIGURE 3 is a cross-sectional view through the driving gears on line TIL-III of FIGURE 2;

FIGURE 4 is a fragmentary cross-sectional view taken on line IVIV of FIGURE 1 and illustrating additional detail of the means for clamping the variable stroke adjustment;

FIGURE 5 is an end elevational view but with parts shown in cross section taken on line V-V of FIGURE 1;

FIGURE 6 is a fragmentary cross-sectional view through the valve which opens the cylinder to the atmosphere taken generally on line VI-VI of FIGURE 1;

FIGURE 7 is a fragmentary cross-sectional view taken generally on line VIIVII of FIGURE 1;

FIGURE 8 is a cross-section similar to FIGURE 1, but showing the oscillating mechanism and various stroke settings thereby; and

FIGURE 9 is a cross-sectional view similar to FIG- URE 1 showing the piston against the cylinder head at the end of the compression stroke for strokes of three different lengths.

FIGURE 10 is a diagrammatic illustration showing the length of the strokes of the pump.

As shown on the drawings:

In the exemplary form of the pumping mechanism herein described by way of illustration of the principles of the present invention, there is provided two separate pumping units which are exactly alike with the common spiral gear drive, shown in one view only. For the sake of clarity in description, only one side with its drive will be described and it will be understood that such descriptive matter refers to the pumping unit of the opposite side as well except for some features shown on the unsectioned part of the drawing which are common to both pumping units. Thus, there is shown a first pumping unit P and a second pumping unit indicated generally at P Each pumping unit P and P incorporates a cylinder 11 externally threaded at one end as at 12 for screw-threaded connection to a circular frame 13. A cylinder head 14 is shown screw-threaded into the opposite end of the cylinder 11. A piston head is provided and is shown generally at 16. The piston head 16 consists of two parts including a body member 17 and a ring 18. The body member 17 and ring 18 clamp a pair of packing units indicated at 19 and 20, respectively, one of which is designed to hold suction and the other to hold pressure. A pair of nipples 21 and 22 are screw-threaded in firm assembly in the head member 14 of the cylinder 11 and c0- operate with tubing-type conduit 23 and 24 to permit pumping medium to enter or leave the cylinder 11.

A piston rod 26 is connected in firm assembly to the piston head 16 by means of a screw 27. The piston rod 26 is supported by upper and lower ways 28 and 29 which are integral with the circular frame 13.

In order to provide power for operating the pumping mechanism, there is provided a motor shown generally at 30 and having a speed changing mechanism contained within a gear box 31 regulated by a control lever 32. Power is transmitted from a motor shaft 33 to a pump shaft 34 by means of a worm gear 36 co-rotatable with the shaft 33 and engaging a gear 37 keyed to the shaft 34 as at 38. As shown in FIGURE 3, the end of the shaft 33 is supported in bearings indicated at 39 carried within a housing portion of the circular frame 13. A thrust bearing shown at 40 (FIGURE 5) absorbs the thrust of the gear 37 and a bearing 41 absorbs the radial load of the shaft 34. It will be understood that a similar bearing arrangement, not shown, is located in the housing of the other pumping unit P On the other side of the gear 37 there is provided a seal 42 which is used to retain lubricant in the gear housing portion of the circular frame 13, which housing is indicated generally at 43 for better identification.

In accordance with the principles of the present invention, a special mechanism is provided for transmitting the rotational movement of the shaft 34 into reciprocating movement of the piston rod 26 and the piston 16.

Thus, a crank 44 is co-rotatably connected to the shaft 34 by means of a key 46 and a nut 47.

A counterweight 48 (FIGURE 1) is carried by the crank 44 and counteracts the weight of the reciprocating parts. A cam roller 49 is attached to the crank arm 44 and operates in an elongated slot or camming slot 50 of a rocking arm 51.

A ring 52 is rotatably mounted in a housing designated at 53 comprising part of the circular frame 13 and is rotatably supported on a surface shown at 54. The ring 52 is particularly characterized by worm teeth 56 formed on the outer periphery thereof which cooperatively engage and register with a worm 57 carried on a shaft 58 which can be rotatably and adjustably driven by a manual adjustment knob 59. The shaft 58 is supported by bushings 60 and 61 which are locked in place by means of set screws 62 and 63.

Upon rotation of the knob 59 and rotation of the ring 52, sliding contact is effected with a collar 64 which is clamped on its inner edge and on its outer edge by a plurality of screws which engage the adjoining parts such as the circular frame 13 (see FIGURES 2 and 7).

The housing portion 43 forms a grease chamber 67 for the gear 37 and is closed by a plate 68 retained by fastening screws 69.

The collar 64 has formed therein a circumferentially extending slot 70 and a trunnion pin 71 is fixed in the ring 52 and passes through the slot 70 in the collar 64 and through a bearing 72 carried at one end of the rocking arm 51 whichmay also be referred to sometimes herein as an oscillating bar 51. Thus, the rocking arm or oscillating bar 51 is pivotally supported'for oscillation about an axis determined by the trunnion pin 71 and its bearing 72. Moreover, the member 51 will be oscillated upon rotation of the crank 44 and its associated cam roller 49.

A crank pin 73 is fixed in the rocking arm or oscillating bar 51 and projects into a bearing 74 carried by a connecting rod 76. The connecting rod 76 is attached at its opposite end to the piston rod 26 by means of a pin 77 received in a bearing 78. Thus, it will be appreciated that by turning the crank 44, the rocking arm or oscillating bar 51 will oscillate about the pin 71, whereupon the connecting rod 76 will transmit a reciprocating motion to the piston head 16 via the piston rod 26.

In order to lock the ring 52 and prevent creeping rotation of the same, a clamp screw is provided at 80 (FIGURE 1) which is turned by a lever 81 (FIGURE 2) and which presses a corresponding plate 64 tightly against the ring 52. Clearance is provided on one side of the plate 64 as at 83 (FIGURE 4). Clearance is provided at this one spot only.

A groove 84 (FIGURE 1) partially encircles the ring 52 and opens into a hole and fitting 86 (FIGURE 2). The fitting 86 is connected to the fitting 22 by the conduit 24 so that at all times, fluid in the cylinder 11 has free passage to the groove 84. The groove 84 terminates at a hole 87 (FIGURE 6) which, in turn, opens into a valve cavity 88. A long ring-type packing 89 entirely encases the groove 84 to provide a seal between it and the casing provided by the circular frame 13.

The valve body is shown at 90 and is screwed into the valve cavity 88. A movable valve member having a head 91 is normally biased closed by a spring 92 and has an axially projecting needle 93 which projects outwardly at right angles to the valve seat when the needle is not deflected by a cam arm 94 formed on the rocking arm or oscillating bar 51.

It will be noted that the valve stem or needle 93 extends through the slot 70 in the plate 64 and inasmuch as the ring 52 and the swinging arm or rocking arm 51 travel together when adjustment is made, they will always be in the same relation to one another.

In FIGURE 1, the rocking arm 51 is in its extreme left position and at this position the cam extension 94 on the rocking arm 51 is in contact with the valve stem 93 and has pushed the stem 93 sideways, thus tipping its head 91 on the seat opening a passage for fluid to escape into or from a passageway 96 and then to the atmosphere through a vent opening 97 (FIGURE This will open the cylinder )11 to the atmosphere at the end of each suction stroke and will, therefore, equalize the pressure or vacuum in the cylinder 11 after each adjustment. At all other positions of the rocking arm or oscillating bar 51, the valve stem 93 will have its head 91 pressed against the valve seat by the spring 92, thus closing the valve and sealing the air passage 84 from the atmosphere. This is indicated in FIGURE 6.

The pumping mechanism thus far described embodies the structural requisites of obtaining length of stroke adjustment from a maximum to zero and yet the piston will nearly touch the cylinder head for any length of stroke. Moreover, the suction and compression ratios will always be in the ratio of approximately 2 to 1 due to the action of crank 44 and arm 51.

Referring to FIGURES 8, 9 and 10, point A represents the center of the pin 71 and point C represents the center of the cam roller 49. As the crank 44 is rotated by the shaft 34, the cam roller 49 travels in a fixed circular path and as it rolls in the slot 50 of the oscillating bar 51, it causes the bar 51 to travel from a point C in FIGURE 8 to a point C3 in FIGURE 9. In terms of angularity, the difference in travel of the cam roller 49 between FIGURE 8 and FIGURE 9 is shown in FIGURE 10 at 301 and is approximately 120. In the course of this angular traverse, the piston rod 26 and the piston 116 have moved only through the compression stroke, thereby establishing that the pressure stroke (300 in FIGURE 10) is approximately one-half as long as the suction stroke. This ratio can be reversed by changing the direction of rotation of shaft 34. This ratio is preset by moving point 71 closer or farther from center point of shaft 34.

One of the characteristics of the present pumping mechanism is that no matter what the length of the piston stroke, the piston 16 always comes into near contact with the cylinder head 14. This is clearly illustrated in FIG- URE 9. Here it will be observed that whatever adjustment is made by turning the knob 59 and thereby rotating the ring 52 and hence the trunnion pin 71 along the are prescribed by the slot 71 the point B prescribed by the pin 73 will always come to the same point at the end of the compression stroke. Point B is the center of rotation of the shaft 34 and the crank 44, as shown in FIGURE 9.

In order to depict separate settings of the point A, there is also shown in FIGURE 8 an adjustment of the point A to a point A and A of the trunnion pin 71'. However, in each instance, the point B will stop at the center of rotation of the shaft 34, as shown in FIGURE 9.

Thus, the distance from point B to point A is equal to the radius of the slot 70. At the setting of A the connecting rod 76 will swing on the point A along with the oscillating bar 51, thus causing no movement of the piston head 16 or zero compression. Now, if the point A FIGURE 8, is adjusted back to point A the piston will have a travel of X and if adjusted to give the maximum stroke or to point A, the piston 16 will have a stroke equal to Y.

In order that the operator may tell what setting or length of stroke has been obtained after making an adjustment by turning the knob 59, a graduated segment 100 is formed on the periphery of the ring 52 (FIG- URE 2) and moves with the ring 52 to register with an index mark 101. A beveled cut 102 is made in the outer shell of the case 53 to increase the visibility of the gradnations.

It will be appreciated that there has been described hereinabove an arrangement whereby the center line through the piston 16 and the cylinder 11 must pass through the center of the crankshaft and the connecting rod crank pin 73 on the oscillating bar 51, when the piston 16 is at the extreme of the suction stroke. Moreover, the throw of the crank 44 is approximately equal to the desired maximum travel of the piston 16 and the length of the connecting rod 76 is slightly greater than the throw of the crank 44.

The bearing 73 on the oscillating bar 51 is located approximately one'half the throw of the crank 44 measured from the center line of the slot 50. Further, the rocking arm 51 pivot point prescribed by the trunnion pin 71 is disposed on a circle with a radius equal to the length of the connecting rod 76 and the center of that circle corresponds to the center of the crankshaft 34.

There is thus provided a pumping mechanism wherein the length of the suction and pressure strokes may be varied to afford any desired proportion and such adjustment can be effected by a micrometer-type adjustment.

Although minor modifications might be suggested by those versed in the art, it should be understood that I Wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come Within the scope of my contribution to the art.

I claim as my invention:

1. A pump comprising a circular frame,

a shaft rotatably driven in said frame,

a crank connected to said shaft and rotated thereby,

a rocking arm having an elongated slot formed therein,

a cam roller interconnecting said crank and said rocking arm at said slot,

an angularly adjustable ring concentrically outwardly of said shaft and supported by said frame,

a trunnion pin carried by said ring and pivotally connected to said rocking arm,

a cylinder,

2. piston reciprocable in said cylinder,

and a connecting rod connected to said piston and to said rocking arm,

whereby rotation of said shaft will rotate said crank thereby oscillating said rocking bar and reciprocating the piston through a suction and compression stroke, the length proportion of said strokes being adjustable by adjusting said ring in said frame, thereby adjustably positioning said trunnion pin and changing the location of the pivot axis of said rocking arm.

2. A pump as defined in claim which is further characterized by the distance from said trunnion pin to the connection of said connecting rod to said rocking arm being equal to the radius of the circumferentially extending adjustment track of the trunnion pin.

3. A pump as defined in claim 1 which is further characterized by said ring having peripheral teeth formed thereon and an adjustment knob carried by said frame and having a Worm gear connected to said teeth to rotatably adjust said ring.

4. A pump as defined in claim 3 which is further characterized by said ring having graduations formed therein and said frame having an index for comparison indexing therewith.

5. A mechanism for linearly reciprocating a member comprising,

a rotatable crank having a crank pin driven through a fixed circular arc,

a rocking member having a slot receiving said crank pin, a pivot connection coupling said rocking member to a reference support for oscillation of said rocking member upon rotation of said crank pin,

a crank arm for interconnecting the rocking member to the linearly reciprocable member,

means forming an adjustable reference support for said rocking member and comprising means forming a slot disposed to provide a circumferentially extending circular adjustment path for receiving a pivot pin forming said pivot connection,

and means for adjusting and locking said pivot connection at adjusted positions on said circumferentially extending circular adjustment path,

thereby to adjust and vary the length of stroke of the linearly reciprocable member.

6. A mechanism as defined in claim '5 wherein said means forming an adjustable reference support comprises a toothed ring,

and micrometer adjustment means comprising a worm gear having a manual adjustment knob to angularly position said ring and change the position of the pivot connection on said path.

7. A mechanism as defined in claim 5 wherein said rocking member has a bearing for effecting connection to said crank arm,

said bearing being spaced from said pivot connection by a distance equal to the radius of said circumferentially extending path, thereby to insure that the length of stroke will remain uniform regardless of variations in the length proportion of the strokes.

8. A mechanism as defined in claim 5 and further characterized by a cylinder,

said linearly reciprocable member comprising a piston reciprocable in said cylinder,

said cylinder having valve-controlled inlet and outlet means through which fluid is admitted and discharged into and from said cylinder, respectively,

and said mechanism comprising means for regulating said valve-controlled means through a cycle including suction and compression strokes and having means to maintain the duration or time of said strokes in the proportion from about in the order of 2:1 with respect to each other.

9. A reciprocable pump comprising, a cylinder, a piston reciprocable therein and having a piston rod extending out of one end of said cylinder, a connecting rod pivotally connected at one end of said piston rod, a rocking arm having a connecting rod crank pin connected to the other end of said connecting rod, means pivotally supporting said rocking arm for oscillation and comprising a frame,

a ring mounted for angular adjustment in said frame,

a pivot pin on said ring forming said means for pivotally supporting said rocking arm for oscillation,

and means for adjusting said ring,

thereby to vary selectively the position of the pivot axis of said rocking arm for selectively varying the length of the suction stroke and the compression stroke,

said rocking arm having a slot formed therein, and a rotatable crank shaft having a crank pin in said slot to oscillate said arm and reciprocate said piston, the centerline through said piston and cylinder passing through the center of said crank shaft and said connecting rod crank pin when said piston is at one extreme end of its stroke. 10. A reciprocable pump as defined in claim 9, the throw of said pin on said crank shaft being equal to the length of the maximum or greatest piston stroke. 11. A reciprocable pump as defined in claim 9, said pin on said ring being located on a circle with a radius equal to the length of the connecting rod and the center of the circle corresponding to the center of the crank shaft. I 12. A reciprocable pump comprising a cylinder, a piston reciprocable therein and having a piston rod extending out of one end of said cylinder, a connecting rod pivotally connected at one end to said piston rod, a rocking arm having a connecting rod crank pin connected to the other end of said connecting rod, means pivotally supporting said rocking arm for oscillation,

said rocking arm having a slot formed therein, a rotatable crank shaft having a crank pin in said slot to oscillate said arm and reciprocate said piston,

the centerline through said piston and cylinder passing through the center of said crank shaft and said connecting rod crank pin when said piston is at one extreme end of its stroke,

the end of each suction stroke in order to.

equalize the pressure in the cylinder after adjusting the strokes.

References Cited by the Examiner UNITED STATES PATENTS 803,149 10/1905 Clark 103 3s 10 2,183,436 12/1939 Towler 103-38 8 Rush 10338 Valentine 103-38 Martin 103-38 Neyer' 103-38 Eagan -2 103153 Kuehni 23020 Caillaud 103-38 Bennett 10338 Flynn 103-38 LAURENCE V. EFNER, Primary Examiner.

Claims (1)

1. A PUMP COMPRISING A CIRCULAR FRAME, A SHAFT ROTATABLY DRIVEN IN SAID FRAME, A CRANK CONNECTED TO SAID SHAFT AND ROTATED THEREBY, A ROCKING ARM HAVING AN ELONGATED SLOT FORMED THEREIN, A CAM ROLLER INTERCONNECTING SAID CRANK AND SAID ROCKING ARM AT SAID SLOT, AN ANGULARLY ADJUSTABLE RING CONCENTRICALLY OUTWARDLY OF SAID SHAFT AND SUPPORTED BY SAID FRAME, A TRUNNION PIN CARRIED BY SAID RING AND PIVOTALLY CONNECTED TO SAID ROCKING ARM, A CYLINDER, A PISTON RECIPROCABLE IN SAID CYLINDER, AND A CONNECTING ROD CONNECTED TO SAID PISTON AND TO SAID ROCKING ARM, WHEREBY ROTATION OF SAID SHAFT WILL ROTATE SAID CRANK THEREBY OSCILLATING SAID ROCKING BAR AND RECIPROCATING THE PISTON THROUGH A SUCTION AND COMPRESSION STROKE, THE LENGTH PROPORTION OF SAID STROKES BEING ADJUSTABLE BY ADJUSTING SAID RING IN SAID FRAME, THEREBY ADJUSTABLY POSITIONING SAID TRUNNION PIN AND CHANGING THE LOCATION OF THE PIVOT AXIS OF SAID ROCKING ARM.

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