초록 ▼

A vacuum-compression type percussion power tool comprising a housing (12), a cylinder (14) fixed in the housing, a piston (16) reciprocating in the cylinder (14) from a reciprocating drive mechanism such as a crank mechanism (18) driven by an electric motor, or any other suitable drive, a working to

A vacuum-compression type percussion power tool comprising a housing (12), a cylinder (14) fixed in the housing, a piston (16) reciprocating in the cylinder (14) from a reciprocating drive mechanism such as a crank mechanism (18) driven by an electric motor, or any other suitable drive, a working tool (24) installed in the front part of the power tool, and a floating striker (34) which slides inside the cylinder (14) in a space between a tail portion (26) of working tool (24) and the lower end of the piston. The power tool has a sealed auxiliary chamber (54, 56) which is formed by means of a hollow casing (48) which surrounds the cylinder, and a space below the striker (34). The auxiliary chamber is connected to a main working chamber (38), which is formed between the piston and a striker, through a set of compensation holes (44) and a set of idle-stroke holes (46). A check valve (51) is installed in the wall of the auxiliary chamber. This check valve, which connects the auxiliary chamber with an atmospheric-pressure space (49) between the housing and the cylinder, allows flow of air in a direction only from the above-mentioned atmospheric-pressure space to the auxiliary chamber. As a result, during several cycles after starting the power tool, an additional quantity of air will be sucked into the auxiliary chamber via the check valve (51), so that after reaching established conditions, the auxiliary chamber and the main chamber will operate with an increased amount of air, and therefore with an increased pressure at the commencement of each cycle. This will increase the energy of impact.

대표청구항 ▼

A vacuum-compression type percussion power tool comprising: housing means; cylinder means located in said housing means and fixed therein, said cylinder means having inner and outer walls, and a closed bottom wall with an inner and outer sides, said closed bottom wall having a central opening; recip

A vacuum-compression type percussion power tool comprising: housing means; cylinder means located in said housing means and fixed therein, said cylinder means having inner and outer walls, and a closed bottom wall with an inner and outer sides, said closed bottom wall having a central opening; reciprocating drive means supported by said housing means on the side thereof opposite to said bottom wall; piston means slidingly guided in said cylinder means and driven by said reciprocating drive means; a working tool with a tail portion inserted into said cylinder means through said central opening, said working tool having a flange which limits insertion of said working tool into said cylinder means; a floating striker means having upper and lower end faces and located in said cylinder means for sliding therein between said piston means and said tail portion of said working tool inserted into said cylinder; a main working chamber formed in said cylinder means between said piston means and said striker means; a hollow casing having a wall surrounding a portion of said cylinder means and forming a space with said outer walls of said cylinder means; an auxiliary chamber formed by said space of said hollow casing in combination with a space between said bottom wall, said lower end face of said striker means, and said inner walls of said cylinder means; a space which is formed between said housing means, said cylinder means, and said hollow casing, and is connected to the atmosphere; a first set of through holes formed in the wall of said cylinder means above said striker means, said first set of holes connecting said main working chamber with said auxiliary chamber; a second set of through holes in said walls of said cylinder means between said first set of holes and said bottom wall, said second set of holes connecting said space, of said hollow casing with said space below said striker means, said holes of said second set having diameters substantially greater than those of said holes of said first set; one-way valve means in said wall of said hollow casing, said valve means passing air into said auxiliary chamber from said space between said housing means and cylinder means and preventing air from flowing in the opposite direction; and sealing means in said piston means for sealing said piston means against said inner walls of said cylinder means.