Hydraulic trim cylinder for marine stern drives and outboard motors

• US 5,980,339 A
• Filed: 11/12/1997
• Issued: 11/09/1999
• Est. Priority Date: 11/12/1996
• Status: Expired due to Fees

• Current Assignee: Ohio Associated Enterprises, LLC
• Original Assignee: Ohio Associated Enterprises, LLC
• Inventors: Hartman, John E., Venaleck, John T., Dadd, Paul M.
• Primary Examiner(s): AVILA, STEPHEN P
• Application Number:
  US08/968,080
• Time in Patent Office: 727 Days
• Field of Search: 440/65, 440/61, 440/66
• US Class Current: 440/61.00R
• CPC Class Codes: F02B 61/045 for marine engines
• CPC Class Codes: F15B 15/1428 Cylinders F15B15/1438 takes precedence
• CPC Class Codes: F15B 15/1447 Pistons; Piston to piston rod assemblies
• CPC Class Codes: F15B 15/149 Fluid interconnections, e.g. fluid connectors, passages

Abstract

It is an object of the current invention to provide a trim cylinder that is cost effective; it is further an object of the invention to provide a cylinder that has few parts, less than one-third the number of parts of present art; it is further an object of the invention to provide a unique and simple check valve for operation as a shock absorber and further to provide passages integral of the extruded or molded body allowing plumbing to be attached at one end only of the cylinder; also to eliminate the plastic shroud which normally covers unsightly plumbing.

Claims

1. An hydraulic actuator comprising:

a housing having an annular bore; and

a piston slidable within the bore, the piston including;

a body with at least one fluid passage therethrough; and

a relief valve for selectively allowing fluid flow through the at least one passage, the relief valve including an annular spring surrounding an axis of the body and a preload mechanism for urging the spring against the body.

2. The actuator of claim 1, wherein the annular spring is a Belleville washer.

3. An hydraulic actuator comprising:

a housing including a single plastic molded piece having an annular bore therein and an end portion which is substantially closed; and

a piston slidable within the bore, the piston including;

a body with at least one fluid passage therethrough; and

a relief valve for selectively allowing fluid flow through the at least one passage.

4. The actuator of claim 3, further comprising an end cap at the end of the annular bore opposite the end portion.

5. The actuator of claim 3, wherein the end portion has a hole therethrough and the actuator further comprises a tapered plug in the hole.

6. The actuator of claim 3, the body having at least one resilient seal in contact with the molded piece along the bore, the at least one seal being able to accommodate variations in diameter of the bore or changes in diameter of the bore due to changes in pressure within the housing.

7. The actuator of claim 3, wherein the end portion has a hole therethrough and the actuator further comprises a tapered plug insertable in the hole.

8. The actuator of claim 3, the body having at least one resilient seal in contact with the molded piece along the annular bore, the at least one seal being able to accommodate variations in diameter of the annular bore, or changes in diameter of the annular bore due to changes in pressure within the housing.

9. The actuator of claim 3, wherein the end portion includes a bearing.

10. The actuator of claim 9, wherein the end portion further includes an end wall, the end wall and the bearing each having a hole for passage of an insert therethrough.

38. The actuator of claim 3, wherein the body includes at least one cup seal in contact with the molded piece along the annular bore.

39. The actuator of claim 9, wherein the at least one resilient seal includes at least one cup seal.

11. An hydraulic actuator comprising:

a housing having an annular bore, the housing including a cylinder and two end caps adhesively adhered to the cylinder; and

a piston slidable within the bore, the piston including;

a body with at least one fluid passage therethrough; and

a relief valve for selectively allowing fluid flow through the at least one passage.

12. The actuator of claim 11, wherein the cylinder is metal and the end caps are plastic.

13. A relief valve mechanism comprising:

a body having at least one fluid passage therethrough;

an annular spring mechanism alternatively in a closed position preventing fluid flow through the body when the spring mechanism is in contact with the body, or in an open position allowing fluid flow through the body when the spring mechanism is not in contact with the body; and

a preload mechanism for urging the spring mechanism against the body;

wherein the spring mechanism is in the open position when a pressure difference across the spring mechanism is greater than a given value and the spring mechanism is in the closed position when the pressure difference is less than the given value.

14. An hydraulic actuator comprising:

a housing having an annular bore, the housing including a cylinder and at least two end caps adhered to the cylinder, the end caps having a lower modulus of elasticity and stiffness than the cylinder; and

a piston slidable within the bore, the piston including;

a body with at least one fluid passage therethrough; and

a relief valve for selectively allowing fluid flow through the at least one passage.

15. The actuator of claim 14, wherein the cylinder is metal and the end caps are plastic.

16. A relief valve mechanism comprising:

a body having at least one fluid passage therethrough;

an annular spring mechanism alternatively in a closed position preventing fluid flow through the body when at least a portion of the spring mechanism is in contact with the body, or in an open position allowing fluid flow through the body when the at least a portion is not in contact with the body; and

a preload mechanism for urging the spring mechanism against the body.

17. The valve mechanism of claim 16, wherein the spring mechanism includes a Belleville washer and the body has a body land thereon which contacts a first seat of the washer at a first contact line when the spring mechanism is in the closed position.

18. The valve mechanism of claim 17, wherein a maximum distance between the first seat and the body land is a function of the configuration of the at least one fluid passage.

19. The valve mechanism of claim 18, wherein the preload mechanism is a retainer bolt having a bolt land thereon which contacts a second seat of the washer at a second contact line.

20. The valve mechanism of claim 19, wherein the first and second contact lines are circular, the first contact line having a larger radius than the second contact line.

21. The valve mechanism of claim 20, wherein the amount of force urging the spring mechanism against the body may be adjusted by changing the position of the bolt.

22. The valve mechanism of claim 21, wherein the Belleville washer is conformal coated with a soft metal.

23. A method of absorbing shocks in a hydraulic trim cylinder comprises the steps of:

preventing flow around a piston body by use of a perimeter seal around the perimeter of the body; and

preventing flow through fluid passages in the body by use of an annular seal surrounding an axis of the body which seals by contact with a first seal land on the body and a second seal land on a preloading member connected to the body.

24. A cylinder for an hydraulic system, comprising

an elongate hollow tubular member having at least one end at least partly closed by an end cap,

said end cap having a portion including two surfaces, one of said surfaces facing a surface of the tubular member and the other of said surfaces being exposed to fluid pressure in said tubular member to urge said one surface toward said tubular member in response to such fluid pressure tending to maintain engagement therebetween as pressure increases and physical distortion occurs in response thereto.

31. The cylinder of claim 24 wherein the end cap is made of plastic.

32. The cylinder of claim 24 wherein the end cap is adhesively joined to the tubular member.

25. An hydraulic apparatus, comprising

an elongate hollow tubular member having at least one end at least partly closed by an end closure,

a rod movable in the tubular member and having a part extending beyond the end closure,

the end closure having an opening for passing the rod therethrough, the end closure having a portion at the area of said opening for effecting a seal with said rod in response to increasing pressure in the tubular member, said portion including two surfaces, one of said surfaces facing a surface of the rod and the other of said surfaces being exposed to fluid pressure in said tubular member to urge said one surface toward said rod in response to such fluid pressure tending to maintain sealed relation therewith as pressure increases.

33. The hydraulic apparatus of claim 25 wherein the end closure is made of plastic.

34. The cylinder of claim 33 further comprising an O-ring between the rod and the end cap.

26. An hydraulic device, comprising

an elongate tubular body of molded material, the tubular body having a hollow interior, an end closure molded to one end of the tubular body, a piston in the tubular body, a closure at the other end of the tubular body, and a piston rod extending beyond one of the ends of the tubular body, at least one channel molded in the outside of the tubular body for conducting fluid in the channel, a closure for the channel to retain fluid therein, and a fluid connection between said at least one channel and the hollow interior for fluid flow therebetween.

27. The device of claim 26, said molded material comprising a plastic material.

35. The device of claim 26 wherein the closure for the channel has protrusions which mate with end sections of the at least one channel.

36. The device of claim 35 wherein the protrusions and the end sections are adhesively adhered.

37. The device of claim 26 wherein the at least one channel includes two channels with a prong therebetween.

28. A fluid actuator, comprising,

a body having plural chambers separated by a piston, the piston being movable in the body toward one or the other of the chambers, a rod extending out from the chamber, a closure at one end of the body, the closure having a bearing molded directly therein allowing rotatable connection to an external member to which the actuator is connected.

29. The actuator of claim 28, said body and closure comprising an integrally molded structure.

30. A fluid actuator for marine use to adjust the tilt of an outdrive, comprising:

an elongate tubular housing having a piston slidably movable therein separating the housing into respective chambers on opposite sides of the piston,

a piston rod coupled to the piston,

the actuator being able to be coupled to an outdrive to adjust the tilt thereof,

means for supplying fluid to a respective chamber to urge the piston in a respective direction in the housing to adjust tilt of the outdrive, and

the piston including a body with at least one fluid passage therethrough, and a relief valve for passing fluid from one chamber to the other to allow movement of the outdrive when force exceeding a prescribed magnitude is applied to the outdrive tending to tilt the outdrive, the relief valve including an annular spring surrounding an axis of the body and a preload mechanism for urging the spring against the body.