Pneumatic hammer

Claim 2

A pneumatic hammer comprising: a casing; a barrel in said casing, said barrel being axially movable relative to said casing; a working tool mounted in the front portion of said barrel, said working tool having a shank; an air-distribution device and an impact mechanism with a hammer piston in said barrel, said air-distribution device and impact mechanism ensuring reciprocation of said hammer piston imparting blows at the shank of said working tool under the action of compressed air; a guide bush fixed in the front portion of said barrel, the shank of said working tool being received in said guide bush; a hood mounted on the front portion of the hammer; means preventing said working tool from falling out, said means comprising a lock in the form of a tubular member rotatably mounted on the front portion of said barrel; an end wall at the front end of said lock, said end wall having an non-circular opening; said hood being rotatably mounted on said casing and embracing said lock so as to form an annular space therebetween; an end wall at the front end of said hood, said end wall having a non-circular opening; a first portion of said working tool adjacent to the shank thereof, said first portion having a shoulder, the crosssectional shape of said shoulder corresponding to the shape of the opening of said end wall of said lock, whereby, upon a relative angular rotation of said hood and lock, after said shoulder has been received in the opening of said lock, said working tool is held in said lock from falling out; a second portion of said working tool having a non-circular crosssectional shape corresponding to the shape of the opening of said end wall of said hood so as to ensure an angular rotation of said working tool when in the operative position by rotating said hood; means for locking said working tool in the hammer, said means providing the fixing of the relative angular position of said hood and lock in the operative position at which the openings of said end walls of said hood and lock are not in register, whereby said working tool is positively held in said lock.

Claim 3

A pneumatic hammer comprising: a casing; a barrel in said casing, said barrel being axially movable relative to said casing; a working tool mounted in the front portion of said barrel, said working tool having a shank; an air-distribution device and an impact mechanism with a hammer piston in said barrel, said air-distribution device and impact mechanism ensuring reciprocation of said hammer piston imparting blows at the shank of said working tool under the action of compressed air; a guide bush fixed in the front portion of said barrel, the shank of said working tool being received in said guide bush; a hood mounted on the front portion of the hammer; means preventing said working tool from falling out, said means comprising a lock in the form of a tubular member rotatably mounted on the front portion of said barrel; an end wall at the front end of said lock, said end wall having a non-circular opening; said hood being rotatably mounted on said casing and embracing said lock so as to form an annular space therebetween; an end wall at the front end of said hood, said end wall having a non-circular opening; a first portion of said working tool adjacent to the shank thereof, said first portion having a shoulder, the cross-sectional shape of said shoulder corresponding to the shape of the opening of said end wall of said lock, whereby, upon a relative angular rotation of said hood and lock, after said shoulder has been reCeived in the opening of said lock, said working tool is held in said lock from falling out; a second portion of said working tool having a non-circular cross-sectional shape corresponding to the shape of the opening of said end wall of said hood so as to ensure an angular rotation of said working tool when in the operative position by rotating said hood; means for locking said working tool in the hammer, said means providing the fixing of the relative angular position of said hood and lock in the operative position at which the openings of said end walls of said hood and lock are not in register, whereby said working tool is positively held in said lock, said means for locking said working tool in the hammer comprising: a ring rotatably mounted on said hood, a pin fixed to said ring, said hood having a circular slot and said pin extending through said slot, said lock having a longitudinally extending slot to receive said pin, a leaf spring being fixed to said pin for fixing the relative angular position of said hood and lock, and said hood being externally provided with a projection having a recess in which the free end of said leaf spring is received.

Claim 4

A pneumatic hammer comprising: a casing; a barrel in said casing, said barrel being axially movable relative to said casing; a working tool mounted in the front portion of said barrel, said working tool having a shank; an air-distribution device and an impact mechanism with a hammer piston in said barrel, said air-distribution device and impact mechanism ensuring reciprocation of said hammer piston imparting blows at the shank of said working tool under the action of compressed air; a guide bush fixed in the front portion of said barrel, the shank of said working tool being received in said guide bush; a hood mounted on the front portion of the hammer; means preventing said working tool from falling out, said means comprising a lock in the form of a tubular member rotatably mounted on the front portion of said barrel; an end wall at the front end of said lock, said end wall having a non-circular opening; said hood being rotatably mounted on said casing and embracing said lock so as to form an annular space therebetween; an end wall at the front end of said hood, said end wall having a non-circular opening; a first portion of said working tool adjacent to the shank thereof, said first portion having a shoulder, the cross-sectional shape of said shoulder corresponding to the shape of the opening of said end wall of said lock, whereby, upon a relative angular rotation of said hood and lock, after said shoulder has been reCeived in the opening of said lock, said working tool is held in said lock from falling out; a second portion of said working tool having a non-circular cross-sectional shape corresponding to the shape of the opening of said end wall of said hood so as to ensure an angular rotation of said working tool when in the operative position by rotating said hood; means for locking said working tool in the hammer, said means providing the fixing of the relative angular position of said hood and lock in the operative position at which the openings of said end walls of said hood and lock are not in register, whereby said working tool is positively held in said lock, said means for locking said working tool in the hammer comprising: a ring rotatably mounted on said hood, a pin fixed to said ring, said hood having a circular slot and said pin extending through said slot, said lock having a longitudinally extending slot to receive said pin, a leaf spring being fixed to said pin for fixing the relative angular position of said hood and lock, and said hood being externally provided with a projection having a recess in which the free end of said leaf spring is received.

Claim 5

A pneumatic hammer comprising: a casing; a barrel in said casing, said barrel being axially movable relative to said casing; a working tool mounted in the front portion of said barrel, said working tool having a shank; an air-distribution device and an impact mechanism with a hammer piston in said barrel, said air-distribution device and impact mechanism ensuring reciprocation of said hammer piston imparting blows at the shank of said working tool under the action of compressed air; a guide bush fixed in the front portion of said barrel, the shank of said working tool being received in said guide bush; a hood mounted on the front portion of the hammer; means preventing said working tool from falling out, said means comprising a lock in the form of a tubular member rotatably mounted on the front portion of said barrel; an end wall at the front end of said lock, said end wall having a none-circular opening; said hood being rotatably mounted on said casing and embracing said lock so as to form an annular space therebetween; an end wall at the front end of said hood, said end wall having a non-circular opening; a first portion of said working tool adjacent to the shank thereof, said first portion having a shoulder, the cross-sectional shape of said shoulder corresponding, to the shape of the opening of said end wall of said lock, whereby, upon a relative angular rotation of said hood and said lock, after said shoulder has been received in the opening of said lock, said working tool is held in said lock from falling out; a second portion of said working tool having a non-circular cross-sectional shape corresponding to the shape of the opening of said end wall of said hood so as to ensure an angular rotation of said working tool when in the operative position by rotating said hood; means for locking said working tool in the hammer, said means comprising said lock having a radial hole, a pin mounted in said radial hole of said lock, said hood having a circular slot and at least one longitudinally extending slot communicated with said circular slot, said hood being axially spring-loaded relative to said casing so as to take the position at which said pin is received in said longitudinally extending slot for fixing the relative angular position of said hood and lock in which said openings of said end walls thereof are not in register, whereby said working tool is positively held in said lock.

Claim 6

A pneumatic hammer comprising: a casing; a barrel in said casing, said barrel being axially movable relative to said casing; a working tool mounted in the front portion of said barrel, said working tool having a shank; an air-distribution device and an impact mechanism with a hammer piston in said barrel, said air-distribution device and impact mechanism ensuring reciprocation of said hammer piston imparting blows at the shank of said working tool under the action of compressed air; a guide bush fixed in the front portion of said barrel, the shank of said working tool being received in said guide bush; a hood mounted on the front portion of the hammer; means preventing said working tool from falling out, said means comprising a lock in the form of a tubular member rotatably mounted on the front portion of said barrel; an end wall at the front end of said lock, said end wall having a none-circular opening; said hood being rotatably mounted on said casing and embracing said lock so as to form an annular space therebetween; an end wall at the front end of said hood, said end wall having a non-circular opening; a first portion of said working tool adjacent to the shank thereof, said first portion having a shoulder, the cross-sectional shape of said shoulder corresponding, to the shape of the opening of said end wall of said lock, whereby, upon a relative angular rotation of said hood and said lock, after said shoulder has been received in the opening of said lock, said working tool is held in said lock from falling out; a second portion of said working tool having a non-circular cross-sectional shape corresponding to the shape of the opening of said end wall of said hood so as to ensure an angular rotation of said working tool when in the operative position by rotating said hood; means for locking said working tool in the hammer, said means comprising said lock having a radial hole, a pin mounted in said radial hole of said lock, said hood having a circular slot and at least one longitudinally extending slot communicated with said circular slot, said hood being axially spring-loaded relative to said casing so as to take the position at which said pin is received in said longitudinally extending slot for fixing the relative angular position of said hood and lock in which said openings of said end walls thereof are not in register, whereby said working tool is positively held in said lock.

Claim 7

A pneumatic hammer according to claim 3, wherein said barrel has a radial hold coaxial with said radial hole of said lock, and said pin is provided with a shank receiver in said radial hole of the barrel.

Claim 8

A pneumatic hammer according to claim 3, wherein said barrel has a radial hole, said lock has a second radial hole, and there is provided a second pin having one end mounted in said radial hole of the barrel, the free end of the pin bEing received in said radial hole of said lock.

Claim 9

A pneumatic hammer comprising: a casing; a barrel in said casing, said barrel being axially movable relative to said casing; a working tool mounted in the front portion of said barrel, said working tool having a shank; an air-distribution device and an impact mechanism with a hammer piston in said barrel, said aid-distribution device and impact mechanism ensuring reciprocation of said hammer piston imparting blows at the shank of said working tool under the action of compressed air; a guide bush fixed in the front portion of said barrel, the shank of said working tool being received in said guide bush; a hood mounted on the front portion of the hammer; means preventing said working tool from falling out, said means comprising a lock in the form of a tubular member rotatably mounted on the front portion of said barrel; an end wall at the front end of said lock; said end wall having a non-circular opening; said hood being rotatably mounted on said casing and embracing said lock so as to form an annular space therebetween; an end wall at the front end of said hood, said end wall having a non-circular opening; a first portion of said working tool adjacent to the shank thereof, said first portion having a shoulder, the cross-sectional shape of said shoulder corresponding to the shape of the opening of said end wall of said lock, whereby, upon a relative angular rotation of said hood and said lock, after said shoulder has been received in the opening of said lock, said working tool is held in said lock from falling out; a second portion of said working tool having a non-circular cross-sectional shape corresponding to the shape of the opening of said end wall of said hood so as to ensure an angular rotation of said working tool when in the operative position by rotating said hood; means for locking said working tool in the hammer, said means comprising said lock having a radial hole, a pin mounted in said hole of said lock, said hood having a circular slot and at least one longitudinal slot communicated with said circular slot, said hood being axially spring-loaded relative to said casing so as to take the position at which said pin is received in said longitudinally extending slot for fixing the relative angular position of said hood and lock at which the openings in said end walls thereof are not in register, whereby said working tool is positively held in said lock, said barrel having a radial hole, a second pin being mounted in said radial hole of the barrel, said lock having a circular slot and said second pin having the free end movably received in said circular slot.

Claim 10

A pneumatic hammer comprising: a casing; a barrel in said casing, said barrel being axially movable relative to said casing; a working tool mounted in the front portion of said barrel, said working tool having a shank; an air-distribution device and an impact mechanism with a hammer piston in said barrel, said aid-distribution device and impact mechanism ensuring reciprocation of said hammer piston imparting blows at the shank of said working tool under the action of compressed air; a guide bush fixed in the front portion of said barrel, the shank of said working tool being received in said guide bush; a hood mounted on the front portion of the hammer; means preventing said working tool from falling out, said means comprising a lock in the form of a tubular member rotatably mounted on the front portion of said barrel; an end wall at the front end of said lock; said end wall having a non-circular opening; said hood being rotatably mounted on said casing and embracing said lock so as to form an annular space therebetween; an end wall at the front end of said hood, said end wall having a non-circular opening; a first portion of said working tool adjacent to the shank thereof, said first portion having a shoulder, the cross-sectional shape of said shoulder corresponding to the shape of the opening of said end wall of said lock, whereby, upon a relative angular rotation of said hood and said lock, after said shoulder has been received in the opening of said lock, said working tool is held in said lock from falling out; a second portion of said working tool having a non-circular cross-sectional shape corresponding to the shape of the opening of said end wall of said hood so as to ensure an angular rotation of said working tool when in the operative position by rotating said hood; means for locking said working tool in the hammer, said means comprising said lock having a radial hole, a pin mounted in said hole of said lock, said hood having a circular slot and at least one longitudinal slot communicated with said circular slot, said hood being axially spring-loaded relative to said casing so as to take the position at which said pin is received in said longitudinally extending slot for fixing the relative angular position of said hood and lock at which the openings in said end walls thereof are not in register, whereby said working tool is positively held in said lock, said barrel having a radial hole, a second pin being mounted in said radial hole of the barrel, said lock having a circular slot and said second pin having the free end movably received in said circular slot.