US1740931A - Pump piston - Google Patents

Description

Patented Dec. 24, 1929 UNITED, STATES PATENT OFFICE PUMP PISTON Application: filed April 20,

This invention relates to a novel construction for expanding the piston packing of a pump piston and has for its object to provide a piston packing adjusting means coacting with the piston rod which will rotate one head when the piston packing is adjusted by rotating the respective element of the piston rod adjusting means.

Another object is the novel construction and operation that not only provides a means for adjusting the pressure of the piston packing, relative to the walls of the cylinder in which it reciprocates, by manual force, but with each adjustment of the piston packing,

the angular position of the piston packing is shifted transversely about its axis.

Another object is to provide a means for adjusting the piston packing of a pump piston by manual force, without dismantling any major part of the pump in which the piston is installed.

With these and other objects in view, the invention resides and consists in the construction and novel combination and arranger ment of parts hereinafter more fully described, illustrated in the accompanying drawings, and pointed out in the claims hereto appended, it being understood that various changes in the form, proportion,

size and minor details of construction within the scope of the claims may be resorted to without departure from the spirit of sacrificing any, of the advantages of the invention.

or corresponding parts throughout the several figures of the accompanying drawings forming a part of this specification, and upon which, I

Figure 1, is a central longitudinal section through my improved piston construction.

Figure 2, is a transverse sectional view through the piston at 2 2, showing the typical formation of the packing and heads.

Referring in detail'to the characters of reference marked upon the drawing 1 represents the crosshead, of the reciprocating pump, that connects the steam piston and operating mechanism with the water pump piston 22. It is into this crosshead 1, that I Similar characters of reference denote like 1929. Serial No. 356,845.

screw my novel piston rod which comprises a solid rod 4, a threaded sleeve 5 and a tubular rod 6 which encases a portion of the solid rod 4.

By referring to Fig. 1, of the drawing, it will be noted the main elements of the piston proper 2, namely the piston member 7 and the piston follower 8, are both connected directly to the piston rod 4 and that the tubular rod 6 serves only to rotate the head or socalled piston follower 8. This said tubular rod 6 has no tension or compression stress due to the reciprocating action of the piston 2 upon the fluid being pumped.

lVhile this piston construction is substantially the same in the formation of the piston packing as my Patent Number 1,474,201, dated Nov. 13th, 1923 wherein I use a ratchet wrench as a lever to adjust my piston packing and also the solid rod and the tubular rod therein are fixed against longitudinal movement, it should be noted that in this improvement the tubular rod-moves in a longitudinal movement and I use a Stillson wrench as my lover to adjust the piston packing.-

In my pending application Serial No. 101,969, dated April 14, 1926 the tubular rod is fixed against longitudinal movement and both of the heads of the piston proper rotate simultaneously, where in this improvement the tubular rod moves in alongitudinal di-' rection and but one of the heads rotate while the other head is fixed against rotation.

In my Patent No. 1,650,877, dated Nov. 29, 1927 both the heads of the piston proper are adapted to move in a longitudinal direction, however in this improvement but one of the heads move in a longitudinal direction while being rotated and the other head is fixed against longitudinal movement by a shoulder upon the solid piston rod 4.

This shoulder 9 on the solid piston rod is the main difference in this construction over that in my Patent No. 1,650,877 Also it will be noted that I have omitted a positive-interlocking construction between the two piston heads 7 and 8 in this improvement.

At this time it may be well to note that I have provided a locknut 10 that has threaded engagement 11 with the piston rod 4. How- 100 ever I can eliminate this locknut 10 and the mechanism will function allright and just as efiicient. And should I at anytime eliminate said locknut 10, I will also be able to eliminate making the threaded sleeve 5 a separate part, and in lieu of this said separate part 5 will incor orate a raised shoulder on the solid rod 4. owever it should be noted that this raised shoulder part 5 is merely provided to suit the threads on a standard pump crosshead.

Also note that head solid rod 4 in either a tapered fit manner or a straight fit manner without the shown threaded engagement 12, and would perform its function equally as well.

By holding the head 7 against rotation at the time of the turning of the rod 6, and by the rotation of the head 8 which will move in a longitudinal direction relative to head 7 I am able to compress and/or expand the pliable packing 13. The solid rod 4 being held stationary against rotation and having threaded engagement with the head 8, permits the said head 8 to move in a longitudinal direction when being rotated.

As before stated the shoulder 9 prevents the head 7 from movingin a longitudinal direction toward head 8 and locknut 14 looks the head 7 upon the rod 4.

The head 8 having a right handed threaded engagement with the rod 4 and the head 7 having a lefthanded threaded engagement with the rod 4, will tend to positively tighten the head 7 .onto the rod 4 when-the head 8 is rotated in the proper direction. These threaded engagements may hands if so desired.

An important feature of this construction is the transverse twist that I give to the pliable piston packing 13 when the head 8 is rotated, this is caused by the frictional resistance of the pressure between the conical surfaces 15 and 16 of the heads 8 and 7 respectively. The head 7 being fixed against rotation tends to create a frictional resistance to the turning of the packing 13 when the head 8 is rotated, this resistance causes a slight twist to the axial position of the packing 13 which in turn is ideal for the wearing resistance of the packing to the reciprocating movement of the piston and tends to lengthen the life of the packing.

While I have shown the surfaces of the heads 7 and 8 in conical formation they can.

be made in any shape or form and used to good advantage, however a conical surface is more efiicient than that of other shape or formation.

It will be seen that my improvement resides in the holding of one head 7 against rotation while the other head 8 is rotating, and to merely reverse the operation will be clear to, those skilled in the art.

Sleeve 5 is a tube pressed onto the solid rod 7 could be pressed onbe to opposite 4 and pinned. It will have'threads on its outer diameter for threaded engagement with the crosshead 1. This sleeve -5 can be threaded onto the shaft or rod 4 if so desired. It is fixed against longitudinal movement.

Tubular rod 6 is a tube or sleeve mounted about the solid rod 4. It will be fixed into the head 8 and is adapted to rotate head 8.

Solid rod 4 is basically the piston rod of the piston, the entire strain due to the pumping of the fluid coming directly upon this rod 4. This rod 4 serves to connect the pump piston 2 with the motive force that drives piston 2 and it has threaded engagement 17 and 12 with the heads 8 and 7'respectively. It is held stationary onto the cross-head 1 by locknut 18 and has a threaded portion 11 for a threaded engagement for the locknut 10. In this case the threads 17 are right handed while the threads 12 are left handed and the threads 11 are left handed. A shoulder formation 9 is provided to limit the longitudinal movement of the head 7. \Vhile another shoulder 19 is provided on the opposite end portion of this rod 4 to limit the travel of the sleeve 5 in a longitudinal direction.

Head 8 is the only head that can move in a longitudinal direction when the packing is being compressed and it is a circular disc in formation having an outward, disposed formation 20 that will bear in an inward dis posed formation 21in head 7. The inner diameter 22 of this said formation 21 will contain threads for threaded engagement with the stationary rod 4. And on the opposite end 23 a means will be provided to enable the rod 6 to be fixed into this head 8. Conical surfaces 15 are provided adjacent the packing 13.

Head 7 is a cylindrical disc having a conical surface 16 similar to that of head 8. And it contains a female connection 21 provided to permit a centralizing bearing for head 8.

This head 7 will be secured against rotation on rod 4 by threads 12 and locknut 14.

The packing 13 will be of a pliable mate rial, preferably made of some suitable rubber composition, although any composition Wlll do equally as well. It will be formed to suit the shape of the surfaces 15 and 16 on heads 8 and'7 and its inner diameter will bear directly on the outward disposed formahave threaded engagement with the rod 4.

From the abovedescription it will be seen that I have arranged a series of fixed and moving parts so arranged so as to utilize energy derived from some external source for the purpose of doing work, and that when the rod 6 is rotated in its proper direction the head 8 will be moved in a longitudinal direction toward head 7 and the packing 13 both compressed and expanded and if said rod 6 is rotated in a reverse direction the packing will be permitted to contract and resume its former shape.

gocknut 14 is provided to lock head 7 onto r0 4.

The threads throughout the entire device will be of such hands as-to more securely fix their respective member against movement or to efliciently move their respective member in relation to other elements as the case demands.

What I claim and desire to secure by Letters Patent isr, 1. A pump plunger comprising a piston rod, a sleeve disposed about the piston rod, a head element secured to the sleeve and having threaded connection with the piston rod, a second head element fixed to the piston rod,

a pliable packing between the head elements,

a locknut on said piston rod.

2. In a reciprocating pump, a pump piston comprising two elements one of which is adapted to be rotated and moved in a longitudinal direction, the other being fixed against rotation and longitudinal movement, a packing between said elements and shifted by the change in relative positions of said element's,

- a stationary rod having threaded engagement comprising two coniform members, one bein with 'both elements for imparting longitudinal movement to one element and a rotatable rod mounted on said stationary rod and connected to the movable element to rotate the same by the rotation of said rod. 3. In a reciprocating pump, a pump piston adapted to be moved in a longitudinal direction toward the other, a packing between the members adapted to be shifted by the change a in the relative positions of saidmembers, a statlonary rod having threaded engagement with the movablemember, and means for turning one member to adjust their positions relative to each other whereby the packing is moved.

tation and connected to the piston rod, a packing disposed between the heads, and means providing a shoulder on the other end of the piston rod for securing the piston rod to the piston rod coupling.

6. A pump plunger comprising a piston rod, a sleeve disposed about the piston rod, two heads each threadedly mounted on one end of the piston rod in a right and left handedt-hreaded formation respectively, one of the heads secured to the sleeve, a packing disposed between the heads, and means for turning the sleeve whereby upon rotation of one head and sleeve the said head will be adjusted toward or away from the other head to expand the packing or to permit it to contract when the piston rod is held stationary.

7. In a reciprocating pump, a pump piston comprising two members one of which is adapted to be rotated and longitudinally adjustable relative to the other, the other member secured against rotation and longitudinal movement in one direction, a pliable packing between said members adapted to be shifted upon contracting the relation of said members, a tubular rod connected to one of the said members, a stationary means within the tubular rod having threaded connection with one of the said members, and means for rotating the said rod whereby rotation of said rod will change the relative positions of said members and shift the packing.

8. In a reciprocating pump, a pump piston comprising two members, one of which is longitudinally adjustable relative to the other, a pliable packing between said members, a tubular rod having connection with one member and adapted to be rotated to impart a rotatg ing movement to said member, and means extending within the said tubular rod having threaded engagement with said member to shift said member by rotation of said member whereby the pliable packing is adjusted by the rotation of said member, the other member and means within the tubular rod being held stationary. I

- WILLIAM FREDERICK McMAHON.

4:. In a pump having a piston rod coupling,

a plunger rod secured against rotation relatively thereto, a sleeve disposed about the plunger rod having one end bearing against a locknut, a head rigidly mounted upon the sleeve and also threadedly mounted upon the plunger rod, a second head secured to the plunger rod, a packing disposed between the heads and adapted to be expanded when the sleeve is rotated, causing one head to rotate and move toward the other. I v

5., In a pump having a piston rod crosshead or coupling, a piston rod secured against rotation relatively thereto, a sleeve disposed about the piston rod, a first head secured to the sleeve and threadedly connected to the piston rod, 9. second head secured against ro-

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