Hand held hammer machine
First Claim
1. A hand held hammer machine comprising a housing;
- a cylinder in said housing;
spring means in said housing at a forward end of said cylinder in alignment therewith and compressively supported on a frontal abutment in said housing;
a limit stop in said housing;
a tool and tool sleeve assembly axially movable in said housing relative to said cylinder at said forward end of said cylinder between a first position in which said tool and sleeve assembly further compresses said spring means away from said frontal abutment in response to axial movement of said tool and sleeve assembly towards said cylinder, and a second position in which said limit stop in said housing limits said movement of said tool and sleeve assembly towards said cylinder;
a drive piston reciprocably movable in said cylinder at rear end of said cylinder;
a hammer piston reciprocably movable in said cylinder between said drive piston and said tool and sleeve assembly;
said hammer piston being driven by said drive piston through a working chamber defined in said cylinder between said drive piston and said hammer piston;
portion means defined in a wall of said cylinder swept by said hammer piston during reciprocal movement of said hammer and drive pistons for providing fluid communication between ambient air and said working chamber so as to alternately reduce pressure in said working chamber to cause said hammer piston away from said tool, and to increase pressure to provide a gas cushion in said working chamber for driving said hammer piston to impact on said tool during movement of said drive piston towards said tool;
said first and second positions of said tool and sleeve assembly being selected to define a range of movement of said hammer piston such that said hammer piston sweeps past and uncovers said porting means upon said impact of said hammer piston against said tool.
3 Assignments
0 Petitions
Accused Products
Abstract
A hand held hammer machine comprises a housing (10) with a cylinder (11) therein, in which a reciprocating drive piston (40) via a gas cushion in a working chamber (44) repeatedly drives a hammer piston (15) to impact on the neck (17) of a tool (20) carried by the machine housing (10) as soon as a feeding force is applied via the machine housing (10) to the tool (20) and an interposed recoil spring (23) pre-stressed between fixed shoulders (28,22) in the housing (10) starts being compressed in response to tool penetration into the housing (10). Therein and within the spring (23) and around the path of movement of a piston rod (13) of the hammer piston (15) is affixed one end (26) of a sleeve (25), which by its other end forms a stop (30) limiting the penetration of the tool neck (17) into the machine housing (10) to a maximally allowable extent. The range of movements of the neck (17) wherein it can receive repetitive impacts lies between beginning and maximal compression of the spring (23) counted from its precompressed state which defines an idle position for the neck (17), and in that idle position and within that range proper uncovering of porting (45) in the cylinder wall is assured with the hammer piston seal (16) out of hazardous alignment with said porting (45) at the impacting instants.
35 Citations
10 Claims
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1. A hand held hammer machine comprising a housing;
- a cylinder in said housing;
spring means in said housing at a forward end of said cylinder in alignment therewith and compressively supported on a frontal abutment in said housing;
a limit stop in said housing;
a tool and tool sleeve assembly axially movable in said housing relative to said cylinder at said forward end of said cylinder between a first position in which said tool and sleeve assembly further compresses said spring means away from said frontal abutment in response to axial movement of said tool and sleeve assembly towards said cylinder, and a second position in which said limit stop in said housing limits said movement of said tool and sleeve assembly towards said cylinder;
a drive piston reciprocably movable in said cylinder at rear end of said cylinder;
a hammer piston reciprocably movable in said cylinder between said drive piston and said tool and sleeve assembly;
said hammer piston being driven by said drive piston through a working chamber defined in said cylinder between said drive piston and said hammer piston;
portion means defined in a wall of said cylinder swept by said hammer piston during reciprocal movement of said hammer and drive pistons for providing fluid communication between ambient air and said working chamber so as to alternately reduce pressure in said working chamber to cause said hammer piston away from said tool, and to increase pressure to provide a gas cushion in said working chamber for driving said hammer piston to impact on said tool during movement of said drive piston towards said tool;
said first and second positions of said tool and sleeve assembly being selected to define a range of movement of said hammer piston such that said hammer piston sweeps past and uncovers said porting means upon said impact of said hammer piston against said tool. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
- a cylinder in said housing;
Specification