Back to results
US 4,065,112 AGranted
Hydraulic jack cushioning apparatus
AssigneeTowmotor Corporation
InventorsEdward V. Leskovec, Ralph D. Porter
Life of this patent
Estimating the term…
Abstract
Cushioning apparatus for cushioning a hydraulic jack is disclosed which includes a plunger reciprocably mounted within a blind bore. The plunger sequentially closes off a plurality of axially spaced orifices provided through the wall of the bore as the plunger moves from a first position adjacent the open end of the bore to a second position adjacent its closed end, thereby progressively restricting the escape of fluid from the bore so as to slow the movement of one of the telescopic members of the jack toward another.
Claims9
Apparatus for cushioning the movement of one telescopic member of a hydraulic jack toward another, comprising:
- wall means carried by one of said telescopic members and forming a blind bore having an open end and an opposite closed end;
- a plunger reciprocably mounted within said blind bore for movement between a first position adjacent the open end of the bore and a second position adjacent its closed end and defining a variable chamber therebetween;
- surface means carried on the other of said telescopic members for engagement with said plunger to effect the displacement of the plunger toward its second position as the telescopic members approach a predetermined position relative to each other;
- a plurality of axially spaced orifices formed through said wall means between said first and second positions of the plunger so as to be sequentially closed off by the plunger as it moves towards its second position, thereby progressively restricting the escape of fluid from the chamber as the plunger approaches its second position;
- biasing means for normally biasing said plunger toward its first position;
- said plunger has an inner end having a spring cavity formed therein, and said biasing means includes a helical compression spring having one end seated within said spring cavity and its other end seated against the closed end of the blind bore;
- a snap ring disposed within a groove formed adjacent the open end of the bore for retaining the plunger therewithin;
- said other member has an end cap closing one end thereof, said end cap having an inner transverse surface thereon providing said surface means;
- said other member has an end portion adjacent said end cap and said wall means is mounted to said end portion with the open end of said bore facing said end cap of the outer member;
- and
- said plunger has an elongated stem extending therefrom, said stem having a distal end extendable from the open end of the bore for engagement with the transverse surface of the end cap.
8 more elements
Apparatus for cushioning the movement of one telescopic member of a hydraulic jack toward another, comprising:
- wall means carried by one of said telescopic members and forming a blind bore having an open end and an opposite closed end;
- a plunger reciprocably mounted within said blind bore for movement between a first position adjacent the open end of the bore and a second position adjacent its closed end and defining a variable chamber therebetween;
- surface means carried on the other of said telescopic members for engagement with said plunger to effect the displacement of the plunger toward its second position as the telescopic members approach a predetermined position relative to each other;
- a plurality of axially spaced orifices formed through said wall means between said first and second positions of the plunger so as to be sequentially closed off by the plunger as it moves towards its second position, thereby progressively restricting the escape of fluid from the chamber as the plunger approaches its second position;
- biasing means for normally biasing said plunger toward its first position;
- said plunger has an inner end having a spring cavity formed therein, and said biasing means includes a helical compression spring having one end seated within said spring cavity and its other end seated against the closed end of the blind bore;
- a snap ring disposed within a groove formed adjacent the open end of the bore for retaining the plunger therewithin;
- and
- said other member has an end cap closing one end thereof, said end cap having an inner transverse surface thereon and a blind bore formed into said surface, and wherein said wall means includes a cylindrical sleeve having a first end portion mounted within said blind bore of the end cap and a second end portion extending therefrom.
6 more elements
Apparatus for cushioning the movement of one telescopic member of a hydraulic jack toward another, comprising:
- wall means carried by one of said telescopic members and forming a blind bore having an open end and an opposite closed end;
- a plunger reciprocably mounted within said blind bore biased by a helical compression spring for movement between a first position adjacent the open end of the bore and a second position adjacent its closed end and defining a variable chamber therebetween;
- surface means carried on the other of said telescopic members for engagement with said plunger to effect the displacement of the plunger toward its second position as the telescopic members approach a predetermined position relative to each other;
- a plurality of axially spaced orifices formed through said wall means between said first and second position of the plunger so as to be sequentially closed off by the plunger as it moves towards its second position, thereby progressively restricting the escape of fluid from the chamber as the plunger approaches its position;
- retainer means disposed within a groove formed adjacent the open end of the bore for retaining the plunger therewithin;
- said other member has an end cap closing one end thereof, said end cap having an inner transverse surface thereon providing said surface means;
- said one member has an end portion adjacent said end cap and said wall means is mounted to said end portion with the open end of said bore facing said end cap of the outer member;
- and
- said plunger has an elongated stem extending therefrom, said stem having a distal end extendable from the open end of the bore for engagement with the transverse surface of the end cap.
6 more elements
Dependencies are inferred from the claim text.