Adjustable self locking shoring strut
First Claim
1. A shoring strut comprising:
- a cylinder;
a drive piston and a working piston recprocatingly mounted in said cylinder;
a first chamber in said cylinder for receiving a first fluid, said first chamber being in fluid communication with a first side of said drive piston;
a second chamber in said cylinder containing a hydraulic fluid, said second chamber being in fluid communication with a second side of said drive piston and a first side of said working piston;
a port for injecting said first fluid into said first chamber;
wherein when said first fluid is injected through said port into said first chamber, pressure is applied to said first side of said drive piston and said drive piston is urged in a first direction, thus urging hydraulic liquid from said second chamber against said first side of said working piston, thereby actuating said shoring strut.
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Accused Products
Abstract
A pneumatic/hydraulic shoring strut is disclosed for bracing walls in various situations. The shoring strut is provided with features that allow it to be infinitely adjustable and self-locking. In a preferred embodiment, the strut contains an internal biasing member that urges contraction when pneumatic pressure is released. More particularly, the pneumatic/hydraulic shoring strut of the present invention is composed of an inner and outer cylinder which form an annular recess therebetween. The cylinders are mounted in first and second caps and an annular drive piston is positioned within the annular recess, creating first and second chambers. A port for injecting air into the first chamber is mounted on the outer cylinder and hydraulic fluid is sealed in the second chamber. A channel is provided in one of the caps providing fluid communication between the second chamber and an interior cavity located within the inner cylinder where a working piston is reciprocatingly mounted. The channel has a unidirectional flow control valve and a releasable flow restriction control mounted therein thereby facilitating the self-locking feature of the strut.
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Citations
24 Claims
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1. A shoring strut comprising:
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a cylinder; a drive piston and a working piston recprocatingly mounted in said cylinder; a first chamber in said cylinder for receiving a first fluid, said first chamber being in fluid communication with a first side of said drive piston; a second chamber in said cylinder containing a hydraulic fluid, said second chamber being in fluid communication with a second side of said drive piston and a first side of said working piston; a port for injecting said first fluid into said first chamber; wherein when said first fluid is injected through said port into said first chamber, pressure is applied to said first side of said drive piston and said drive piston is urged in a first direction, thus urging hydraulic liquid from said second chamber against said first side of said working piston, thereby actuating said shoring strut. - View Dependent Claims (2, 3, 4)
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5. A shoring strut comprising:
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an outer cylinder and an inner cylinder, said inner cylinder being coaxially aligned within said outer cylinder and said inner cylinder having an outer diameter less than an inner diameter of said outer cylinder thereby forming an annular recess therebetween, said inner cylinder further having an interior cavity; an annular drive piston reciprocatingly mounted in said annular recess, said recess being divided into a first chamber and a second chamber by said annular drive piston; a working piston having an axially aligned piston rod extending therefrom, said working piston being reciprocatingly mounted in said interior cavity of said inner cylinder; a channel providing fluid communication between said second chamber of said annular recess and said interior cavity of said inner cylinder; a hydraulic fluid in said second chamber of said recess and said interior cavity; a port for injecting a first fluid into said first chamber of said recess; wherein said first fluid is injected through said port into said first chamber, pressure is applied to one side of said annular drive piston and said annular drive piston is urged in a first direction, thus expelling hydraulic liquid from said second chamber of said recess into said interior cavity, thereby actuating said working piston. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A shoring strut comprising:
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an outer cylinder and an inner cylinder, said inner cylinder being coaxially aligned within said outer cylinder and said inner cylinder having an outer diameter less than an inner diameter of said outer cylinder thereby forming an annular recess therebetween, said inner cylinder further having an interior cavity; a working piston recprocatingly mounted in said interior cavity of said inner cylinder; an expandable bladder mounted in said annular recess; a channel providing fluid communication between said recess and said interior cavity of said inner cylinder; a hydraulic fluid in said recess and said interior cavity; a port for injecting a first fluid into said bladder; wherein when said first fluid is injected through said port into said bladder, hydraulic fluid in said recess is urged through said channel into said interior cavity, thereby actuating said working piston. - View Dependent Claims (23, 24)
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Specification