US 6,205,894 B1Granted

Automatic stop device for screw striking machine

AssigneeMax Co., Ltd.

InventorHiroshi Tanaka

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Abstract

An automatic stop machine for a screw striking machine includes a driver bit, an air pressure cylinder having a piston, and an air motor driving the piston and rotationally driving the driver bit. The automatic stop machine comprises an open/close valve, a contact arm, and an air passage. The open/close valve is disposed in an air supply passage to the air motor. The contact arm freely slidable along a nose portion of the screw striking machine, projects from the leading end of the nose portion, and stops the air motor by closing the open/close valve when the contact arm is pushed into a main body of the screw striking machine and is moved upwardly as the screw is screwed. The air passage in which pressurized air passes from a space defined by a back surface of the piston in the piston when the piston reaches the vicinity of bottom dead point. Pressure of the pressurized air supplied through the air passage and upward movement of the contact arm cooperatively cause the open/close valve to close when the piston reaches the vicinity of bottom dead point.

Claims10

Dependent claims

A screw striking machine including a driver bit extending from a leading end of a nose portion of the screw striking machine and having a bit to be engaged with the head of a screw, an air pressure cylinder having a piston which said driver bit is rotatably connected thereto, an air motor driving said piston of said air pressure cylinder to strike said screw and rotationally driving said driver bit to screw said screw, and an automatic stop mechanism comprising:

a primary open/close valve disposed in an air supply passage to said air motor;
a contact arm freely slidable along the nose portion of said screw striking machine, projecting from the leading end of the nose portion, and stopping said air motor by closing said primary open/close valve when said contact arm is pushed into a main body of said screw striking machine as said screw is screwed;
and
an air passage in which pressurized air passes from a space defined by a back surface of said piston in said piston when said piston reaches approximately one end of its travel,
wherein pressure of the pressurized air supplied through said air passage and movement of said contact arm into the main body of the screw striking machine cooperatively cause said primary open/close valve to close when said piston reaches the approximately one end of its travel.

2 more elements

A screw striking machine comprising:

a driver bit extending from a leading end of a nose portion of the screw striking machine and including a bit to be engaged with the head of a screw;
an air pressure cylinder including a piston which said driver bit is rotatably connected thereto;
an air motor driving said piston of said air pressure cylinder to strike said screw, and rotationally driving said driver bit to screw said screw;
a primary open/close valve disposed in an air supply passage to said air motor;
a contact arm freely slidable along the nose portion of said screw striking machine, projecting from the leading end of the nose portion, and stopping said air motor by closing said primary open/close valve when said contact arm is pushed into a main body of said screw striking machine as said screw is screwed;
and
an air passage in which pressurized air passes from a space defined by a back surface of said piston in said piston when said piston reaches the approximately one end of its travel,
wherein pressure of the pressurized air supplied through said air passage and movement of said contact arm into the main body of the screw striking machine cooperatively cause said primary open/close valve to close when said piston reaches approximately one end of its travel.

5 more elements

Dependencies are inferred from the claim text.