US3867895A

US3867895A - Integral hydraulic tensioning assembly

Info

Publication number: US3867895A
Application number: US325648A
Authority: US
Inventors: Robert Larry Ameigh
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-01-22
Filing date: 1973-01-22
Publication date: 1975-02-25
Anticipated expiration: 1992-02-25

Abstract

An integral hydraulic tensioning assembly for applying a tension force to an operated member rigidly affixed to a piston. A single, integral housing is provided with a first chamber having a displacement piston disposed therein. A displacement pump element is disposed in a second chamber in the housing with an outlet of the second chamber in fluid communication with the first chamber in the housing. Upon operation of the pump element, hydraulic fluid is introduced under pressure into the first chamber to produce a force on the piston which is applied as a tension force through a piston rod to a particular cable or backstay. A selectively engageable gripping means is also provided to maintain the tension force on the cable.

Description

[ Feb. 25, 11975 United States Patent [1 1 Ameigh Primary ExaminerLloyd L. King INTEGRAL HYDRAULIC TENSIONING ASSEMBLY [76] Inventor:

Assistant Examiner--Randolph A. Reese Attorney, Agent or FirmMarn & Jangarathis [5 7] ABSTRACT An integral hydraulic tensioning assembly for applying [22] Filed:

a tension force to an operated member rigidly affixed to a piston. A single, integral housing is provided with a first chamber having a displacement piston disposed therein. A displacement pump element is disposed in a second chamber in the housing with an outlet of the second chamber in fluid communication with the first chamber in the housing. Upon operation of the pump element, hydraulic fluid is introduced under pressure into the first chamber to produce a force on the piston References Cited which is applied as a tension force through a piston UNITED STATES PATENTS rod to a particular cable or backstay. A selectively en- 4/1951 gageable gripping means is also provided to maintain the tension force on the cable.

4 Claims, 6 Drawing Figures 2,547,055 Stephens............................. 3,393,598 7/1968 Bettinger 3,620,182 ll/l97l Russell 3,730,125 5/1973 Krueger..............................

I. V m 4 r O /1 0. 5 W %//NZ nu t 5 r 2 PATENTEDFEB25I975 a; 8-67. 895 sumap Flg 6 INTEGRAL HYDRAULIC TENSIONING ASSEMBLY BACKGROUND .OF THE INVENTION This invention relates to an integral hydraulic tensioning assembly for applying a tension force to an operated member, such as, for example, a cable or backstay on a sailing vessel.

ln numerous applications, it is required to apply a tension force to an elongated, flexible member (such as a cable) and to maintain the particular member in tension. While the manual application of a tension force to a cable is generally adequate in other instances how ever, an average manual tension force of say 50-l00 lbs. is insufficient. For example, it is frequently necessary to apply a much greater than manual tension force to a backstay or headstay of a sailing vessel or to the support ropes or cables of a large tent structure.

Previously, techniques have been developed for applying increased tension forces to such elongated, flexible members as described above. For example, various hydraulic systems are known in which a hydrualic fluid is introduced under pressure into a piston chamber to apply a hydraulic force to the piston and to an associated piston rod. Such hydraulic systems include a supply of hydraulic fluid, and a suitable pump for supplying hydraulic fluid under pressure. Depending upon various parameters such as the capacity of the pump, the area of the piston face, etc. greatly increased forces, in either tension or in compression, may be developed.

It will be appreciated that in certain applications, the typical previously known hydraulic systems as described above, are not well suited. As many of such hydraulic systems are large, heavy and require numerous connections of tubing for the hydraulic fluid, difficulty is frequently encountered in moving conventional hydraulic systems from one location to another. In the event that it is necessary to apply a tension force to a rope or cable wherein a greater than manual tension force is called for, a hydraulic system as described above is extremely useful. Where the rope or cable is part of a system supporting a large tent for example, one requirement of the particular hydraulic system is that it be easily transportable, as tents are usually employed as temporary structures.

Similarly, when a hydraulic system is to be employed to apply a tensioning force to a cable or backstay of a sailing vessel, it is many times desirable to be able to easily disconnect and remove the hydraulic system when the associated sail has been retired and the vessel is not in use. In this manner the hydraulic system can be used for other applications rather than being limited to use on, and effectively increasing the capital cost of, a single vessel. However, as noted above, as previously known hydraulic systems are large, heavy and require idly mounted below the deck of the vessel while the cable, to which a tensioning force is to be applied, extends above the deck through a separate locking means for maintaining the tensioning force applied by the hydraulic actuator. It will be appreciated that as a number of hydraulic and mechanical connections are required in order to install this hydraulic system on a particular vessel, and that the system does not readily lend itself to being transported on to a vessel each time the system is to be used, or to be readily removed from one vessel and easily installed on another vessel.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide an improved hydraulic assembly for applying a force to an operated member.

It is another object of the present invention to pro vide an integral hydraulic tensioning assembly for applying a tensioning force to an elongated, flexible memher.

It is yet another object of the present invention to provide an integral hydraulic tensioning assembly for applying a tensioning force to a cable or backstay of a sailing vessel with the assembly being readily transportable and admitting of simple installation.

It is a further object of the present invention to provide an integral hydraulic tensioning assembly in which a pump and a piston means are disposed in a single housing.

It is a still further object of the present invention to provide an integral hydraulic assembly in which the amounts of tubing and the conduits for the hydraulic fluid of the device are reduced, thereby reducing the possibility of leakage of the hydraulic fluid.

It is yet a further object of the present invention to provide a selectively engageable locking means for use with an operated member of the integral hydraulic tensioning assembly.

It is yet another object of the present invention to provide, upon operation, a selectively engageable locking means which may be further tightened to assure that a tensioning force is maintained in the event of failure of the integral hydraulic tensioning assembly.

Various other objects and advantages of the invention will become clear from the following detailed description of an exemplary embodiment thereof and the novel features will be particularly pointed and in connection with the appended claims.

In accordance with the present invention, an integral hydraulic tensioning assembly is provided including a housing having two chambers with a piston means disposed in each chamber thereby defining two zones in each of said chambers and wherein a conduit means provides fluid communication between respective zones of each of said chambers whereby an increase in hydraulic pressure in one zone of one chamber causes a flow of hydraulic fluid through said conduit means to apply a hydraulic force to said piston in said other chamber.

BRIEF DESCRIPTION OF THE DRAWING The invention will be more clearly understood by reference to the following detailed description of an exemplary embodiment thereof in conjunction with the accompanying drawing in which:

FIO. I shows a perspective view of the integral hy' draulic tensioning assembly of the present invention;

FIG. 2 shows a partial sectional elevational view of the integral hydraulic tensioning assembly of the present invention;

FIG. 3 shows a sectional view of a locking assembly of the present invention taking along line 33 of FIG.

FIG. 4 shows a further sectional view of the locking assembly taken along line 44 of FIG. 3; and

FIG. 5 shows yet another sectional view of the locking assembly taken along line 44 of FIG. 5;

FIG. 6 shows a partial sectional elevational view of a further embodiment of the integral hydraulic tensioning assembly of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1, there is shown an integral hydraulic tensioning assembly 10 of the present invention connected to a cable 11 by means of a rigging apparatus 11A. The assembly 10 is also connected by means of a pin and yoke assembly 13 to a fixed surface 12 such as the deck of the vessel. Surface 12, may of course be substantially horizontal or at any desired angle as the present invention is not limited to use with vertical surfaces. Furthermore, it will be realized that while a pin and yoke assembly is shown, other means for securing the assembly 10 to a surface may be employed. Similarly, the rigging apparatus 11A may be a ring rigidly affixed to the assembly 10 through which cable 11 is secured. Also, it will be appreciated that the cable 11 may be any suitable elongated, flexible member to which a tensioning force is to be applied. Such a cable 11 may, in practice, be a headstayor backstay of a sailing vessel, or a wire or rope which assists in the support of a tent-like structure. Furthermore cable 11 will be of sufficient strength such that greater than manual tension forces may be applied without damage thereto.

Referring to FIG. 2 illustrating the detailed features of the integral hydraulic tensioning assembly 10, there is provided a single unitary housing, generally indicated as 14 with a portion thereof constructed in the form of a cylinder 15 and including a first chamber and a second chamber 26. A displaceable piston element 16 including a gasket 17 is disposed within a first chamber 20 of the housing 14 and defines first and second zones A and B, respectively. The gasket 17, which may be formed of any suitable material is provided on piston 16 to assure that the piston 16 is displaceable within the chamber 20 yet provides a seal to prevent fluid communication between the zones A and B. A cylinder head portion 21 including a suitable gasket 19 is provided to enclose the cylindrical portion 15 of housing 14 while a central aperture in the cylinder head portion 21 is adapted to receive cylinder rod 18. The gasket 19, is provided on the cylinder head portion 21 to permit movement of cylinder rod 18 while blocking fluid communication between the zone B of the chamber 20 and the exterior of the cylinder head portion 21. Although the cylindrical portion 15 is shown in FIG. 2 as threadably engaged with the housing 14, it will be appreciated that the housing 14 and the cylindrical portion 15 may be formed ofa unitary construction. Also, the cylinder head portion 21 may be threadably engageable with cy- V lindrical portion 15.

The mechanics for generating a hydraulic force will now be described. A pump element 27 is disposed in the chamber 26 and is connected by arm 28 to a handle sleeve 22 by means of a pin 30 in slot 31 of the handle sleeve 22. The handle sleeve 22 is adapted to receive a bar handle 23. It will be understood that the bar handle 23 may be retained in handle sleeve 22 by way of a compression fitting or the handle sleeve 22 and the bar handle 23 may both be threaded such that bar handle 23 is threadably engageable with the handle sleeve 22. Also, the handle sleeve 22 and bar handle 23 may be of a single unitary construction.

The handle sleeve 22 is pivotably connected to a shoulder 25 of the housing 14 by means of a pin 24 which extends through the shoulder 25 and the handle sleeve 22. A further shoulder 34 of the housing 14 is provided with an aperture therein which is substantially circular in cross-section and is defined by the wall 33 in the shoulder 34.

A pump head element 32, which like cylindrical portion 15, is threadably engageable with a portion of the housing 14 and is provided with a central aperture therein adapted to receive the arm 28 therethrough. Also, a gasket 46 is provided on the pump head element 32 to allow reciprocation of the arm 28 while sealing the chamber from the exterior of the pump head element 32. The chamber 26 which, like the chamber 20, is provided within the housing 14 and is in fluid communication with a conduit 36 by means of a passage 35 extending from the chamber 26. A relief valve 37 is disposed in housing 14 to selectively permit or prevent fluid communication between the passage 35 and the passage 38 while a seating element 40 of a bypass valve is similarly disposed to either permit or prevent fluid communication between the passage 35 and chamber 39. The zone A of the chamber 20 acts as a sump or reservoir of hydraulic fluid, and as will be described subsequently, such hydraulic fluid is returned to the zone A by way of the passage 41 in the housing 14. Finally, hydraulic fluid to be pumped by the pump element 27 is selectively permitted to flow through the valve 42 from the zone A to a chamber 43 in the housing 14. A valve 44 is disposed in cooperation with pump element 27 to selectively permit a hydraulic fluid to be introduced into the chamber 26 as will be described subsequently.

In order to assure that a tension force applied to the cable 11 (FIG. 1) is maintained after the integral hydraulic pump and actuator device 10 has been operated, a retaining means, generally indicated as 48, is provided for locking the cylinder head portion 21 of the housing 14 to the cylinder rod 18. To effect a locking operation, a split locking nut is disposed about the shoulder 51 at the end of the cylinder head portion 21 of the housing 14 and about the cylinder rod 18. An interior surface 52 of the split locking nut 50 and an op posing surface portion 53 of the cylinder rod 18 are threaded such that in a locked position the split locking nut 50 may be tightened on cylinder rod 18 even further by means of a wrench (not shown) or other suitable tool. As will be described subsequently in detail, a locking cam 54 is pivotally mounted on shoulder bolts 55 while a handle 56 is rigidly connected to the cam 54 to effect the necessary pivoting thereof.

With reference now to FIG. 3, the split locking nut 50 about the threaded portion of cylinder rod 18 is illustrated in adisengaged position. The handle 56 is positioned such that a planar cam surface58 is adjacent to one side of split locking nut 50 with the two portions thereof held apart under the influence of the compression springs 59 and 60.

In FIG. 4, the split locking nut 50 is shown in an engaged or locked position with the cam 54 having been rotated by the operation of the handle 56 such that the extremity of the cam surface 57 is in contact with the side of locking nut 50. In FIG. 5, the split locking nut 50 is also shown in an engaged position in which the compression force of the compression spring 59 is overcome by the rotation of the cam 54 as shown in FIG. 4. The compression spring 59 is suitably mounted on a member 61 and a threaded end portion 62 is engaged with a threaded aperture 63 in the split locking nut 50. It will be understood that the compression spring 60 is similarly mounted in the split locking nut 50.

The operation of the integral hydraulic tensioning assembly will now be described with reference to FIG. 2. The raising or lowering of the bar handle 23 in the direction of the arrow is effective to pump hydraulic fluid on each stroke thereof. The operation of the pump in assembly 10 illustrated in FIG. 2 is therefore doubling acting. Assuming that bar handle 23 is initiallyin the position shown, operation is initiated by raising the bar handle 23. The pump element 27 is displaced upwardly in the chamber 26 by the upward motion of the arm 28 while the valve 44 in the pump element 27 remains closed.

Thus, hydraulic fluid in the chamber 26 is pumped therefrom and through the passage 35 to the conduit 36 and subsequently into the zone B of the chamber as the relief valve 37 and the bypass valve 45 remain closed. The flow of hydraulic fluid into the zone B of the chamber 20 exerts a hydraulic force against the piston l6 and consequently causes the piston 16 and the cylinder rod 18 to be downwardly displaced (FIG. 2) thereby applying a tension force to the cable 11 (FIG. 1) attached to the cylinder rod 18. During this operation, valve 42 opens to allow hydraulic fluid in zone A of chamber 20 to enter chamber 43 and as bar handle 23 is subsequently lowered, valve 42 is closed and the spring bias of valve 44 is overcome to force hydraulic fluid through pump element 27 and chamber 26 to passage 35, conduit 36 and to zone B of chamber 20. In this manner. a hydraulic force is exerted against the piston 16 each time that the bar handle 23 is raised or lowered and therefore, the pumping operation is double acting. The number of strokes of bar handle 23 will vary in accordance with the tension desired in cable I1 and in order to determine when such a tension has been attained, a gage 9 is provided with the assembly 10 as illustrated in FIG. 1. Upon reaching a desired tension in cable II, the retaining means 48 which includes the split locking nut 50 is engaged to relieve the hydraulic force exerted against piston 16.

In order to cause the split locking unit 50 to engage the cylinder head portion 21 of housing 14 and the cylinder rod 18, the handle 56 is rotated to bring the cam surface 57 into contact with the side of the split locking nut 50. Rotation of the handle 56 is continued until the cam 54 has caused the two portions of the split locking nut 50 to overcome the force of the compression springs 59 and 60 and to come into contact. Conveniently, this contact may occur after rotating the handle 56 through say, l80 to reach the position shown in FIG. 4. At this point, the split locking nut 50 exerts a force on the cylinder head portion 21 of the housing 14 and cylinder rod 18 to grip the cylinder rod 18 and to prevent relative motion between the cylinder rod 18 and the cylinder head portion 2l of the housing 14. Also, as noted above, upon effecting a locking operation, the threaded surface 52 of the split locking nut 50 engages the threaded surface 53 of the cylinder rod 18, thus allowing the split locking nut 50 to be tightened even further by means of a wrench or other suitable tool (not shown) as noted above. The split locking nut 50 may be disengaged by rotating the handle 56 until the cam 54 assumes the position shown in FIG. 2 or FIG. 3.

It will be understood that the relief valve 37 is set such that as long as the pressure of hydraulic fluid in passage 35 does not exceed a predetermined level, the relief valve 37 will remain closed and a normal flow of hydraulic fluid will occur in conduit 36. However, in the event that a predetermined pressure level is reached in passage 35 the relief valve 37 will open thus providing fluid communication between the passage 35, through the valve 37, through the passage 38, the chamber 39 and through the passage 41 to the zone A, or the reservoir of hydraulic fluid in the chamber 20. As the hydraulic fluid will not flow through the conduit 36, there will be no hydraulic force to cause the piston 16 to apply a tension force to the cable 11 by way of the cylinder rod 18.

In order to release a tension force applied to the cylinder rod 18 and the cable 11 (FIG. 1) the bypass valve 45 is opened and the split locking nut 50 is released by the appropriate rotation of handle 56. The tension force in cable 11 will then cause the cylinder rod 18 and the piston 16 to be upwardly displaced (FIG. 2) which in turn will force hydraulic fluid from zone B through conduit 36, passage 35, chamber 39 (as bypass valve 45 is opened) and passage 41 to zone A of chamber 20. A tension force may be re-applied by the subsequent closing of bypass valve 45 and operation of the bar handle 23.

A further embodiment of the present invention, wherein an integral hydraulic tensioning assembly employ a single acting pump operation, is illustrated in FIG. 6. As the particular structure and operation of the integral hydraulic tensioning assembly is similar to the assembly illustrated in FIG. 2, reference will be had to only those elements necessary for an understanding of the operation of the assembly depicted in FIG. 6.

A spring biased valve 44' is disposed between the upper end of passage 35 and conduit 36 and valve 42', also spring biased, is disposed between the entrance of chamber 43 and zone A of chamber 20. In order to apply a tension force, bypass valve 45 is closed and the bar handle is raised in the direction of the arrow. As the bar handle 23 is pivotable about shoulder 25', the pump element 27' is lowered in chamber 26' to thereby force hydraulic fluid through passage 35 and valve 44' to conduit 36 and subsequently to zone B of chamber 20. As the bar handle 23 is lowered, the pump element 27' is raised in chamber 26. Although hydraulic fluid is drawn through valve 42 into chamber 26' no pumping action occurs as the bar handle 23 is lowered. Upon a desired tension force being produced by a particular number strokes of the bar handle 23, the retaining means 48 is then engaged to relieve the hydraulic force as previously described with regard to the assembly illustrated in FIG. 2. In order to release the tension force, the retaining means 48 is disengaged and the bypass valve 45 is opened to allow the tension existing in the cable 11 (FIG. 1) to move piston 16 to the right in chamber thereby transferring hydraulic fluid from zone B to zone A of the chamber 20.

It will be appreciated that while the conduit 36 is shown in FIGS. 2 and 6 as being substantially external of the housing 14, the conduit 36 is essentially an integral portion of the housing as is the cylindrical portion 15 and the cylinder head portion 21. While the conduit 36 could, for example, be a passage in the housing 14, it is preferred to provide a substantially rigid conduit as shown in FIG. 2 to keep the weight and size of the housing 14 as small as possible. Also, while the shoulder 34 of the housing 14 has been disclosed with an aperture therein defined by the walls 33 of the shoulder 34, it will be readily understood that any suitable means may be provided for releasably securing the integral hydrau lic tensioning assembly 10 to the bracket 13 (FIG. 1).

While the invention has been particularly described with reference to a cable or backstay on a sailing vessel, it will be obvious that this invention may be utilized with any flexible elongated member to which a tensioning force is to be applied. Consequently, it is apparent from the foregoing and various other modifications and changes in form and details may be made without departing from the spirit and scope of the invention. It is therefore intended that the appended claims be interpreted as including all such changes and modifications.

What is claimed is:

1. An integral hydraulic tensioning assembly for applying a tensioning force to an operated member in response to a hydraulic force applied to a displaceable piston means comprising:

a housing having first and second chambers;

said piston means defining first and second zones in said first chamber, said first zone of said first chamber comprising a reservoir of hydraulic fluid;

a pump means disposed in said second chamber;

first conduit means for providing fluid communication from said second chamber to said second zone of said first chamber such that displacement of said piston means causes hydraulic fluid to flow through said first conduit means thereby applying a tensioning force to said operated member;

a second conduit means including a first valve means formed in said housing to permit hydraulic fluid to flow from said second chamber to said first zone of said first chamber should the hydraulic pressure exceed a predetermined pressure of said first valve means;

second valve means disposed in said second conduit means to permit hydraulic fluid to selectively flow from said second zone to said first zone of said first chamber; and

a selectively engageable locking means for preventing relative motion between said housing and said operated member, said locking means includes a split locking nut assembly and a cam means, said cam means being mounted for revolution on said lock nut device such that revolution of said cam means selectively engages and disengages said split locking nut assembly.

2. The integral hydraulic tensioning assembly as defined in claim 1 in which juxtaposed surface portions of said operated member and said split locking nut assembly are threaded whereby upon engagement of said split locking nut assembly, said threaded surface portions are engaged.

3. The integral hydraulic tensioning assembly as defined in claim 1 wherein said pump means comprises a handle member and a single acting pump element operated by said handle member for pumping hydraulic fluid on alternate strokes of said handle member.

4. The integral hydraulic tensioning assembly as de fined in claim 1 wherein said pump means comprises a handle member and a double acting pump element operated by said handle member for pumping hydraulic fluid on successive strokes of said handle member.

Claims

1. An integral hydraulic tensioning assembly for applying a tensioning force to an operated member in response to a hydraulic force applied to a displaceable piston means comprising: a housing having first and second chambers; said piston means defining first and second zones in said first chamber, said first zone of said first chamber comprising a reservoir of hydraulic fluid; a pump means disposed in said second chamber; first conduit means for providing fluid communication from said second chamber to said second zone of said first chamber such that displacement of said pistOn means causes hydraulic fluid to flow through said first conduit means thereby applying a tensioning force to said operated member; a second conduit means including a first valve means formed in said housing to permit hydraulic fluid to flow from said second chamber to said first zone of said first chamber should the hydraulic pressure exceed a predetermined pressure of said first valve means; second valve means disposed in said second conduit means to permit hydraulic fluid to selectively flow from said second zone to said first zone of said first chamber; and a selectively engageable locking means for preventing relative motion between said housing and said operated member, said locking means includes a split locking nut assembly and a cam means, said cam means being mounted for revolution on said lock nut device such that revolution of said cam means selectively engages and disengages said split locking nut assembly.

4. The integral hydraulic tensioning assembly as defined in claim 1 wherein said pump means comprises a handle member and a double acting pump element operated by said handle member for pumping hydraulic fluid on successive strokes of said handle member.