HYDRAULIC LOCKING DEVICE

• US 3,760,911 A
• Filed: 12/22/1971
• Issued: 09/25/1973
• Est. Priority Date: 12/22/1971
• Status: Expired due to Term

• Current Assignee: Clyde R. Porter, Percy L. Porter
• Original Assignee: Clyde R. Porter, Percy L. Porter
• Inventors: Porter, Percy L., Porter, Clyde R.
• Primary Examiner(s): Halvosa, George E. A.
• Application Number:
  US05/211,023
• Time in Patent Office: 643 Days
• Field of Search: 188/266,300,322 92/13.4 248/354H,161,407,188.5 297/355 287/58CT
• US Class Current: 188/300
• CPC Class Codes: B60N 2/231 by hydraulic actuators
• CPC Class Codes: F15B 15/24 for restricting the stroke
• CPC Class Codes: F15B 15/26 Locking mechanisms
• CPC Class Codes: Y10T 403/32426 Plural distinct positions

Abstract

A piston on a piston rod divides a cylinder into two hydraulic locking chambers, fluid flow between the two chambers being through the piston under control of a locking valve. A rotary adjustment sleeve of stepped configuration permits adjustment of the piston stroke. A reservoir for hydraulic fluid adjoins one locking chamber so that leakage from the chamber is into the reservoir. The reservoir is cut off when the piston moves out of its normal limit position.

Claims

1. In a hydraulic locking device to control relative movement between two members comprising a hydraulic cylinder means connected to one of the two members, a piston rod means extending through at least one end of the cylinder means and connected to the other of the two members, a piston united with the piston rod means and dividing the interior of the cylinder means into two variable hydraulic locking chambers, a reservoir for hydraulic fluid to replinish the fluid between said two chambers, the reservoir having a movable wall, means controlling flow of fluid between said chambers, spring means acting on said movable wall to place the fluid in the reservoir under pressure, means selectively controlling flow of fluid from said reservoir, and a manually releasable locking valve controlling fluid flow between the two chambers to control the freedom of the piston, the improvement to permit selective adjustment of the range of movement of the piston thereby to adjust the range of relative movement between the two members, comprising:

a first stop operatively connected to the cylinder means;

a second stop operatively connected to the piston rod means and cooperative with the first stop to limit the range of the stroke of the piston, one of said two stops being formed with a circumferential series of steps to cooperate selectively with the other stop to limit the stroke of the piston, one of said two stops being fixed relative to the means to which it is operatively connected, the other of said two stops being rotatably adjustable relative to the means to which it is operatively connected to limit the stroke of the piston by the steps of said series of steps selectively, index means fixed against rotation relative to the means to which the rotatable stop is operatively connected, said index means releasably engaging the rotatable stop to hold the rotatable stop against rotation selectively at a series of rotary positions of the rotatable stop to selectively limit the stroke of the piston, and means urging said rotatable stop axially toward its limit position whereby the rotatable stop may be retracted in opposition to said urging means and while retracted may be rotated relative to said index means to change the rotary position at which the rotatable stop is releasably held by said index means.

2. In a hydraulic locking device to control relative movement between two members comprising a hydraulic cylinder means connected to one of the two members, a piston rod means extending through at least one end of the cylinder and connected to the other of the two members, a piston united with the piston rod means and dividing the interior of the cylinder means into two variable hydraulic locking chambers, and a manually releasable locking valve controlling fluid flow between the two chambers to control the freedom of the piston, the improvement to permit selective adjustment of the range of movement of the piston thereby to adjust the range of relative movement between the two members, comprising:

a first stop fixedly connected to the cylinder;

a second stop in the form of a stop sleeve of stepped configuration rotatably mounted on the piston rod for rotation relative thereto to selected positions for Selectively limiting the stroke of the piston;

index means fixedly mounted on the piston rod in releasable engagement with the stop sleeve to hold the stop sleeve at selected positions of rotation, said stop sleeve being axially retractable from engagement with the index means to permit adjustment rotation of the stop sleeve; and

spring means urging the stop sleeve into engagement with the index means.

3. An improvement as set forth in claim 2 which includes a sleeve of light-transmitting material enclosing the stop sleeve for the dual purpose of keeping foreign matter out of the hydraulic locking device and of making visible the rotary position of the stop sleeve relative to the fixed stop.

4. In a hydraulic locking device to control relative movement between two members comprising a hydraulic cylinder means connected to one of the two members, a piston rod means extending through at least one end of the cylinder means and connected to the other of the two members, a piston united with the piston rod means and dividing the interior of the cylinder means into two variable hydraulic locking chambers, and a manually releasable locking valve controlling fluid flow between the two chambers to control the freedom of the piston, the improvement to permit selective adjustment of the range of movement of the piston thereby to adjust the range of relative movement between the two members, comprising:

a first stop operatively connected to the cylinder means;

a second stop operatively connected to the piston rod means and cooperative with the first stop to limit the range of the stroke of the piston, one of said two stops being formed with a circumferential series of steps to cooperate selectively with the other stop to limit the stroke of the piston, one of said two stops being fixed relative to the means to which it is operatively connected, the other of said two stops being rotatably adjustable relative to the means to which it is operatively connected to limit the stroke of the piston by the steps of said series of steps selectively;

index means fixed against rotation relative to the means to which the rotatable stop is operatively connected, said index means releasably engaging the rotatable stop to hold the rotatable stop against rotation selectively at a series of rotary positions of the rotatable stop to selectively limit the stroke of the piston, one of said index means and said rotatable stop being axially retractable out of interlocking engagement with the other, and an outer protective member enclosing said rotatable stop to protect said locking device from foreign matter.

5. An improvement as set forth in claim 4 in which the rotatable stop is in the form of a sleeve and is axially retractable out of interlocking engagement with the index means.

6. An improvement as set forth in claim 5 in which the stop sleeve has a radial wall to cooperate with the index means.