US3620182A

US3620182A - Stay adjuster

Info

Publication number: US3620182A
Application number: US860932A
Authority: US
Inventors: David J Russell
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-09-25
Filing date: 1969-09-25
Publication date: 1971-11-16
Anticipated expiration: 1988-11-16

Abstract

A STAY ADJUSTER IS PROVIDED WITH A HYDRAULIC CYLINDER AND PISTON FOR CHANGING THE LENGTH OF A TENSIVELY LOADED STAY ON A SAILBOAT. ONCE ADJUSTMENT HAS OCCURRED, A MECHANICAL LOCK ON THE STAY MECHANISM MAINTAINS THE STAY ADJUSTER IN A POSITIVELY LOCKED POSITON. A PRESSURE GAUGE COMMUNICATED TO THE INTERIOR OF THE HYDRAULIC CYLINDER

AND PISTON PROVIDES AN INDICATION OF BACKSTAY LOADING DURING STAY ADJUSTMENT.

Description

N 1971 v D. J. RUSSELL 3,620,132

STAY ADJUSTER Filed Sept. 25, 1969 INVENTOR.

DAVID J. RUSSELL RESERVOI R ATTORNEYS United States Patent 3,620,182 STAY ADJUSTER David J. Russell, 81 Filbert, Sausalito, Calif.

Filed Sept. 25, 1969, Ser. No. 860,932 Int. Cl. B63h 9/04 U.S. Cl. 114-109 3 Claims ABSTRACT OF THE DISCLOSURE This invention relates to stay adjusters for use on sailing craft having adjustable stays including in their standing rigging and, more particularly, to a hydraulically actuated stay adjuster.

Hydraulically actuated stay adjusters are known. Typically, such stay adjusters are inserted in a segment of a stay. A hydraulic cylinder is connected through appropriate linkages to one segment of the stay and a piston fitted interior of the cylinder connected to another segment of the stay. By forcing hydraulic fluid interior of the hydraulic piston and cylinder, the length of such stay adjusters can be changed to provide various stay loadings and lengths necessary for appropriate tuning of sailboat rigging.

Heretofore, such hydraulic actuated stay adjusters have suffered from two serious disadvantages. First, in order to maintain their adjustment, hydraulic fluid within the cylinder and piston has to be maintained under pressure at all times. As hydraulic systems under pressure are subject to some leakage, such stay adjusters have to be constantly checked and reset to maintain the desired stay length and tension.

Secondly, such stay adjusters are commonly mounted in a position overlying either the tack or clew of a sail. The inevitable fluid leakage occurring from a cylinder and piston having hydraulic fluid therein under pressure for long intervals of time causes oil to fall on the sails resulting in unsightly stains which destroy sail appearance.

An object of this invention is to provide a hydraulic backstay adjuster which can be moved by hydraulics into a desired setting of length and tension and thereafter can be mechanically locked in its adjusted position.

An advantage of this invention is that the hydraulic cylinder and piston only have the hydraulic fluid therein under pressure during adjustment of the stay; when adjustment is completed and the mechanical lock set, pressure on the hydraulic fluid interior of the cylinder and piston is reduced, arresting the tendency for oil leakage.

A further advantage of this invention is that the mechanical lock of this invention prevents inadvertent parting of the stay; while neglect to the tuning of the stay may cause loss in sail efficiency, no inadvertent catastrophic release of the stay can occur in the use of this adjuster.

A further feature of this invention is that the mechanical advantage provided by hydraulics is readily suited to the adjustment of larger sailboat riggings having correspondingly greater tensions therein.

A further object of this invention is to provide in a hydraulic stay adjuster a pressure gauge for determining fluid pressure interior of the cylinder and piston.

An advantage of the pressure guage is that it will afford an indication of stay tension during tuning or adjustment of the rigging.

A further advantage of the pressure guage disclosed in this invention is that it eleminates the need for more complex tension sensing devices such as tuning forks, strain guages and the like, which devices often interfere with the fittings to which stays are fastened.

Other objects, features and advantages of this invention will become more apparent after referring to the following specification and attached drawing in which:

FIG. 1 is a side elevation schematic of a Marconi rig sloop incorporating in its backstay, the stay adjuster of this invention and illustrating in broken lines the tuned position of a sail when the stay adjuster is in a contracted position;

FIG. 2 is an enlarged side elevation in partial section illustrating the expanded disposition of the stay adjuster of this invention and showing in broken lines a contracted position of the stay adjuster of this invention; and,

FIG. 3 is an end elevation section along lines 3-3 of FIG. 2.

With reference to FIG. 1, Marconi rigged sloop A is illustrated having mast 10 held in position by head stay 12, jumpers 14 and backstay 16. As is illustrated, stay adjuster B of this invention is illustrated inserted in and occupying a segment of backstay 16.

Adjustment of adjuster B to shorten the effective length of the backstay causes changing of the mast orientation to a configuration shown in broken lines in FIG. 1. Typically, the lower two-thirds of mast 10 is thrust forwardly. The upper third of the mast flexes arcuately rearwardly. The position of the mast and stay illustrated in broken lines causes flattening of the triangular sail 18 fastened to the mast at its luff 20 and to boom 22 at its foot. As is well known in the art, such flattening of sail 18 is desirable when conditions of heavy wind exist.

Referring to FIGS. 2 and 3, stay adjusters B of this invention is illustrated. Stay adjuster B includes piston portion C, cylinder portion D, locking mechanism E, and hydraulic system F.

Piston portion C of the stay adjuster includes rod 30 having clevis 32 attached to one end, threaded shank 33 configured in rod 30 at the other end, and piston 35 fastened therebetween. Typically, piston 35 is provided with concentric aperture 40 through which rod 30 extends. The piston is secured by bolt 36 to rod 30. As is conventional in hydraulic construction, the periphery of piston 35 is provided with O-ring seal 37 to prevent hydraulic leakage between the sidewalls of the piston and the sidewalls of the cylinder. Likewise, second O-ring seal 38 is provided in piston 35 at aperture 40 to prevent hydraulic leakage along rod 30. A similar O-ring seal between rod 30 and end plate 52 of the hydraulic cylinder is shown in coaxial alignment to O-ring 38.

Cylinder section D of the backstay adjuster includes cylindrical sleeve 50 capped at its end removed from clevis 32 by first end plate 51 and capped at its opposite end adjacent clevis 32 by second end plate 52. End plate 51 is secured to the end of cylinder 50 at first annular groove 54. Likewise, end plate 52 is secured to the opposite end of cylinder 50 at second annular groove 55. Unlike end plate 51, end plate 52 is provided with a raised cylindrical plug 57, which plug incorporates in the cylindrical sidewalls thereof O-ring seal 58 to prevent hydraulic leakage between the sidewalls of cylinder 50 and plug 57.

End plates

51 and 52 are urged one towards another by rods 60 and 61, and bolts 62 threadedly secured to the rods. Typically, rods 60 and 61 are located at diametrically opposite portions of the section of cylinder 50 and extend through aligned

apertures

51 and 52 in end plates.

These

plates

51 and 52 are firmly compressed towards one another by the threaded engagement between bolts 62 threadedly secured to respective rods 60 and 61.

Attachment of the cylinder portion D to the backstay is accomplished by virtue of second clevis 65. Typically, rods 60 and 61 extend away from cylinder portion D a distance exceeding the stroke of piston mounted rod 30. At their respective ends, two bolts 64 secure a rectangular plate 68 to each rod 60 and 61. Plate 68 has in turn fastened to the Sides thereof between rods 60 and 61 two parallel plates 70. Plates 70 when provided with aligned apertures through which pin 72 extends provide the clevis structure 65 attaching cylinder section D to the other section of the stay. As is apparent, rods 60 and 61 as extending outwardly and away from the cylinder define a spatial interval therebetween, which interval permits threaded portion 33 of rod 30 to reciprocally move when hydraulic movement of the piston relative to the cylinder occurs.

Hydraulic pump mechanism F is schematically illustrated. Typically, end plate 52 defines hydraulic fluid aperture 80 extending therethrough to the interface between piston 35 and cylinder end plate 52. Hydraulic piping 82 connected through check valve 83 to lever actuated hydraulic pump 84 and reservoir 85 permits one-Way entry of hydraulic fluid into the cylinder. Upon actuation of pump 84, hydraulic fluid is withdrawn from reservoir 85, passed through check valve 83 and then through piping 82 into cylinder 50 between end plate 52 and piston 35.

A pressure gauge 90 is illustrated connected to hydraulic conduit 82 between check valve 83 and the interior of the hydraulic cylinder and piston. When hydraulic movement of the piston relative to the cylinder occurs, gauge 90 will serve to measure the fluid pressure necessary to effect such movement. As such pressure will be a direct function of the tension between clevis 32 attached piston portion C and clevis 65 attached to cylinder portion D, gauge 90 can be calibrated directly to the tension being transmitted through stay adjuster B.

To provide for the release of hydraulic pressure, throttle valve 92 is here shown connected across hydraulic conduit 82 to reservoir 85. When release of the pressure interior of the cylinder and piston is desired to relax the adjusted stay, throttle valve 92 can be opened to permit fluid to exit from the cylinder and piston through throttle valve 92 and then into reservoir 85.

A mechanical lock of the stay is provided in its adjusted position by locking mechanism E, here illustrated as knurled bolt 97 threadedly secured to threaded portion 33 or rod 30. Typically, when movement of piston 35 interior of cylinder 50 has occurred, bolt 97 will be threadedly moved on rod 30 to a position of abutment with end plate 51. As is apparent, once knurled bolt 97 is in contact with end plate 51, pressure of the hydraulic fluid interior of the cylinder and piston can be relaxed.

Operation of the adjustable back stay of this invention can be readily understood with reference to FIG. 2. Assuming that the back stay adjuster B is in the relaxed position illustrated in solid lines in FIG. 2, lever actuated hydraulic pump 84 is operated. Fluid from reservoir 85 passes through pump 84, check valve 83, conduit 82 and then through inlet aperture 80 into the interface between hydraulic cylinder 35 and end plate 52 interior of cylinder 50. Typically, hydraulic fluid forced into this interval will cause movement of piston 35 away from end plate 52. Such movement of the piston 35 away from the end plate 52 can occur and continue until piston 35 occupies the position shown in broken lines abutting end plate 51 at the opposite end of cylinder 50.

When the desired adjustment of the back stay has occurred, knurled bolt 97 will be moved on the threaded segment 33 of shaft 30 until it lies against end plate 51. In this position, hydraulic pressure interior of the cylindar can be relaxed and a mechanical interlock of piston portion C of the backstay adjuster relative to cylinder portion D of the backstay adjuster will occur.

Relaxing of the backstay adjuster is analogous. Typically, lever actuated pump 84 will be actuated to remove the force of compression of locking mechanism E onto end plate 51. Thereafter, knurled bolt 97 will be threadedly moved away from end plate 51 to the new position of backstay adjustment. When such movement of knurled bolt 97 has been made, throttling valve 92 will be opened. This valve will permit fluid interior of the cylinder and piston to be discharged through the throttle valve 92 directly to the reservoir 85. Fluid discharge will occur until locking mechanism E again seats directly on end plate 51.

It should be apparent to the reader that numerous configurations of a cylinder, piston and mechanical lock therebetween could be used to practice this invention. Likewise, while one embodiment of this invention has been shown and described, it will be apparent that other adaptations and modifications of this device can be made without departing from the true spirit and scope of the invention.

I claim:

1. In a sailboat having a mast, a sail and adjustable tensively loaded rigging extending between a point on said mast and a point on said boat for deflecting said mast and trimming said sail, a segment of said adjustable tensively loaded rigging comprising: a hydraulic cylinder having means for attachment to said standing rigging at one end and defining a bore for receiving a piston at the other end; a hydraulic piston for being received interior of said bore of said cylinder; a rod attached to said piston at one end extending outwardly of the bore of said hydraulic cylinder and having means for attachment to said standing rigging at the other end for completing said segment of said tensively loaded rigging; said hydraulic cylinder and said rod being substantially coaxial with said rigging; means for introducing fluid within said cylinder to urge said piston to move in opposition to the tensive loading of said standing rigging between said hydraulic cylinder and piston; and means for preventing movement of said piston rod with respect to said cylinder responsive to tension in said rigging when cylinder movement has caused adjustment of said rigging.

2. The invention of claim 1 and wherein said fluid introducing means includes a pressure gauge communicated to said fluid introduced interior of said cylinder for detecting tensive loading of said rigging segment during rigging adjustment.

3. The invention of claim 1 and wherein said movement preventing means includes: a plate connected to said cylinder and defining an aperture therethrough for permitting reciprocating movement of said cylinder rod therethrough; a locking nut threadedly movable on said cylinder rod towards and away from said plate for locking said rod with respect to said plate after adjustment of said rigging by said cylinder.

References Cited UNITED STATES PATENTS 2,162,441 6/1939 Mead 114-402 X 2,861,332 11/1958 Hayden 29-452 3,291,090 12/1966 Sevey 114-109 TRYGVE M. BLIX, Primary Examiner