CA2203862A1

CA2203862A1 - Apparatus for coupling a horizontal support beam to a vertical slide column

Info

Publication number: CA2203862A1
Application number: CA 2203862
Authority: CA
Inventors: Jimmy Nelson Potter
Original assignee: GENEVA WELL SERVICE LIMITED
Current assignee: GENEVA WELL SERVICE Ltd
Priority date: 1997-04-28
Filing date: 1997-04-28
Publication date: 1998-10-28

Abstract

A hydraulic cylinder of that type that has a shaft secured to a piston that moves reciprocally in a cylindrical fluid housing and a method of preventing shaft rotation in the same. The method includes a single step of eccentrically securing the shaft to the piston. When the shaft is secured eccentrically to the piston, the shaft cannot and does not rotate.

Description

TITLE OF THE lnv~n~

method of preventing shaft rotation in a hydraulic cylinder and a hydraulic cylinder NAME OF ~h~ ~K:

Jimmy Nelson Potter FIELD OF THE lhv~n 1~

The present invention relates to a method of preventing shaft rotation in a hydraulic cylinder and a hydraulic cylinder constructed in accordance with the described method.

P'' OF THE l~v~n Hydraulic cylinders are used to provide motive force to moving members in a wide variety of m--h i n~c . In many applications, a shaft is reciprocally moved between an extended position and a retracted position. In some applications, correct Al i~; L of this shaft is essential. Rotation of the shaft results in m;cAli~ ~. In such applications, guides are incorporated into the design of the machine to prevent shaft rotation.

One known form of guide is a fixed secondary support that runs through the piston in spaced relation to the shaft, such that the piston runs up and down the fixed secsn~Ary support.
By preventing rotation of the piston, shaft rotation is also prevented. Another known form of guide uses a shaft with a longitudinal central passage. A fixed secondary support runs up through the longitudinal passage of the shaft. The fixed secondary support is mated by spline to the shaft, thereby preventing shaft rotation.

SUMMARY OF T~E lh ~

5What is required is an alternative approach to preventing shaft rotation that results in m; ~Al; 3 ~.

According to one aspect of the present invention there is provided a method of preventing shaft rotation in a hydraulic cylinder of that type that has a shaft secured to a piston that moves reciprocally in a cylindrical fluid housing. The method ;n~ s a single step of eccentrically secllr;ng the shaft to the piston. When the shaft is secured eccentrically to the piston, the shaft cannot and does not rotate.
According to another aspect of the invention there is provided a hydraulic cylinder which includes a cylindrical fluid housing having a first end, a second end and an interior cavity with interior R;~ . A fluid responsive piston is in sliding contact with the interior sidewalls of the interior cavity. The piston reciprocally moves between the first end and the second end of the cylin~r;~Al fluid housing in ~c~ullse to pressure exerted by hydraulic fluid. A shaft i8 eccentrically secured to the piston. The shaft moves 2S reciprocally in relation to the cylindrical fluid housing with vc ~ of the piston.

BRIEF ~ 1~ OF T~E
These and other features of the invention will become more apparent from the following description in which reference is made to the App~n~ drawings, wherein:
FIGURE 1 is a peI~e~ive view of a hydraulic cylinder constructed in accordance with the t~A~hings of the present invention.
FIGURE 2 is a top plan view of the hydraulic cylinder illustrated in FIGURE l.
FIGURE 3 is a side elevation view, in section, of the hydraulic cylinder illustrated in FIGURE 1.

i TT,rn OF T~E l~r~An~ EMBODIMENT

The preferred ~ i L, a hydraulic cylinder generally identified by reference numeral 10, will now be described with reference to FIGURE5 l through 3.

Referring to FIGURE 3, the primary~ ts of hydraulic cylinder 10 are a cylindrical fluid housing 12, a fluid responsive piston 14 and a shaft 16. Cyl;n~r;~Al fluid housing 12 has a first end 18, a second end 20 and an interior cavity 22 with interior R;~ 11R 24. Fluid responsive piston 14 is in sliding contact with interior ~i~ .. 11 R 24 of interior cavity 22. Piston 14 has annular seal grooves 32 in which are disposed "O" ring seals 34. Piston 14 is reciprocally movable between first end 18 and second end 20 of cylindrical fluid housing 12 in response to pressure exerted by hydraulic fluid.
Shaft 16 has a first end 36 and a second end 38. Second end 38 is secured in an eccentric fashion to piston 14, as will hereinafter be further described. Piston 14 has a threaded female aperture 40 sized to received second end 38 of shaft 16 and second end 38 of shaft 16 provided with mating threads 42.
Shaft 16 moves reciprocally in cyl;n~r;cAl housing 12 with .G L of piston 14. First end 36 of shaft 16 extends through opening 26 at first end 18 of cylindrical fluid housing 12. A bushing 44 and a collar 46 are provided as annular sealing means for opening 26. Collar 46 has seal grooves 48 in which are positioned "O" ring seals 50. Referring to FIGURES
l and 2, collar 46 is secured in position by a plurality of threaded studs 52 on which are positioned nuts 54. The assembly of cyl;n~r;eAl fluid housing 12 involves clamping first end 18 and second end 20 together by means of long bolts 56, secured by nuts 58. First end 36 of shaft 16 is also CA 02203862 l997-04-28 provided with threads 60 to permit attac' L to machine c !-~ts (not shown). Referring to FIGURE 3, it is important to note that cylindrical fluid housing 12 and piston 14 have a common central axis, identified by reference numeral 62. In contrast, by virtue of its eccentric connection to piston 14, shaft 16 has an axis, identified by reference numeral 64, that is off-set from axis 62.

The method of use and operation of hydraulic cylinder 10 will now be described with reference to FIGURES 1 through 3.
Referring to FIGURE 3, shaft 16 moves reciprocally in cylindrical fluid housing 12 with the reciprocal . G L of piston 14. However, in view of the eccentric attr-~ L of shaft 16 to piston 14 with axis 64 off-set from axis 62, shaft 16 cannot and does not rotate.

It will be apparent to one skilled in the art that ';f;~ations may be made to the illustrated G ' -~; t without departing from the spirit and scope of the invention as hereinafter defined in the Claims.

Claims

1. A method of preventing shaft rotation in a hydraulic cylinder in which a shaft is secured to a piston that moves reciprocally in a cylindrical fluid housing, comprising the step of:
eccentrically securing the shaft to the piston.

2. A hydraulic cylinder, comprising:
a cylindrical fluid housing having a first end, a second end and an interior cavity with interior sidewalls;
a fluid responsive piston in sliding contact with the interior sidewalls of the interior cavity, the piston being reciprocally movable between the first end and the second end of the cylindrical fluid housing in response to pressure exerted by hydraulic fluid;
a shaft eccentrically secured to the piston, the shaft moving reciprocally in relation to the cylindrical fluid housing with movement of the piston.