Off locking trigger switches

Claim 2

A self-enclosed trigger switch for a portable electric tool affording operation of the tool but preventing accidental operation thereof comprising; an insulating base housing the switch mechanism; a movable spring-biased trigger forming a first part and having a normal off position in which the tool is not in operation and having an alternate on position in which the tool is in operation; a frame forming a second part and mounting said trigger for movement relative to said base and frame and means coupling said trigger to the switch mechanism to allow operation thereof; and an automatically-engaging off lock for said trigger comprising; a resiliently-biased locking member coupled between said movable trigger and said frame parts and means mounting said locking member on one of said parts and locking catch means operative between said locking member and the other part; said mounting means comprising means supporting said locking member on said one part for limited movement relative thereto, and means resiliently biasing said locking catch means toward locking engagement with said other part, and being movable within said limited movement to disengage said locking catch means from said other part; a release button depressible against the force of said resilient bias means to disengage said catch means thereby to allow movement of said trigger from its off to its on position; and said resilient bias means causing automatic reengagement of said catch means when said trigger is released and returned to its off position.

Claim 3

The invention defined in claim 1, wherein said resiliently-biased locking member, mounting means and locking catch means comprises: a spring-biased pin mounted for limited axial movement on said frame; an eccentric locking plate attached to one end of said pin; a release button attached to the other end of said pin; a compression spring on said pin between said frame and said release button; and a stop wall formed on said trigger in alignment with the eccentricity of said locking plate and the axis of said pin behind which said eccentric locking plate is snapped by said compression spring whenever said trigger returns to its off position, said alignment causing the force of trigger pull to Be applied directly to the axis of said pin when said trigger is locked without any torque being applied thereto through said eccentricity; and depression of said release button against the force of said compression spring causes said eccentric locking plate to move clear of said stop wall to allow movement of said trigger.

Claim 4

The invention defined in claim 2, wherein: said trigger is an in-line trigger mounted for linear sliding movement along the top of said base; and said stop wall is formed by a stepped slot in said trigger having an initial short dimension providing said stop wall abutting said locking plate in the undepressed position of the latter and also having an adjacent longer dimension providing clearance for said locking plate in the depressed position of the latter to allow operation of the trigger.

Claim 5

The invention defined in claim 2, wherein; said trigger is an overhanging trigger mounted for pivotal movement on said frame; and said stop wall is formed by a hole in one side of said trigger complementary to said locking plate to freely receive said locking plate and into which said locking plate snaps whenever the trigger returns to its off position and depression of said release button moves said locking plate out of said hole to permit trigger operation.

Claim 6

A self-enclosed trigger switch for a portable electric tool affording operation of the tool but preventing accidental operation thereof comprising: an insulating base housing the switch mechanism; a movable spring-biased trigger having a normal off position in which the tool is not in operation and having an alternate on position in which the tool is in operation; a frame mounting said trigger for movement relative to said base and frame and means coupling said trigger to the switch mechanism to allow operation thereof; and an automatically-engaging off lock for said trigger comprising: a resiliently-biased locking member coupled between said movable trigger and said frame and means mounting said locking member to one thereof and locking catch means between said locking member and the other thereof; a release button depressible against the force of said resilient bias to disengage said catch means thereby to allow movement of said trigger from its off to its on position; and said resilient bias causing automatic reengagement of said catch means when said trigger is released and returned to its off position; said resiliently-biased locking member, mounting means and locking catch means comprising: a leaf spring mounted at one end in a slot in said trigger and being formed with an outward bias to bias the other end portion thereof against said frame and including a projecting catch on said other end portion; and a hole in said frame located so as to receive said catch under the force of said bias whenever said trigger returns to its off position to lock the latter therein.

Claim 7

A self-enclosed trigger switch for a portable electric tool affording operation of the tool but preventing accidental operation thereof comprising: an insulating base housing the switch mechanism; a movable spring-biased trigger having a normal off position in which the tool is not in operation and having an alternate on position in which the tool is in operation; a frame mounting said trigger for movement relative to said base and frame and means coupling said trigger to the switch mechanism to allow operation thereof; and an automatically-engaging off lock for said trigger comprising: a resiliently-biased locking member coupled between said movable trigger and said frame and means mounting said locking member to one thereof and locking catch means between said locking member and the other thereof; a release button depressible against the force of said resilient bias to disengage said catch means thereby to allow movement of said trigger from its off to its on position; and said resilient bias causing automatic reengagement of said catch means when said trigger is released and returned to its off position; said resiliently-biased locking member, mounting means and locking catch means comprising: a leaf spring mounted at one end in a slot in said trigger and being formed with an outward bias to bias the other end portion thereof against said frame and including a projecting catch on said other end portion; and a hole in said frame located so as to receive said catch under the force of said bias whenever said trigger returns to its off position to lock the latter therein.

Claim 8

The invention defined in claim 5, wherein said release button comprises: a spring-biased button including a pin mounting the same in a hole in said frame for limited axial movement therein and being located in registration with said other end portion of said leaf spring so that depression of said button causes said pin to move said projecting catch clear of said hole in said frame to allow movement of said trigger.

Claim 9

A trigger switch for a portable electric tool affording intended operation thereof but automatically locking it against accidental operation whenever the switch is released comprising; a housing for the switch mechanism; a trigger mounted on said housing for limited reciprocal movement between an on position wherein the switch is in operation and an off position wherein the switch is not in operation; a return spring normally biasing said trigger into its off position; and an automatically engaging off lock for said trigger including; a spring-biased locking member coupled between said housing and said Trigger, being mounted to and movable with the trigger and being engagable and disengagable with respect to the housing, engagable to lock the trigger against movement with respect to the housing and disengagable to allow trigger movement with respect to the housing; said engagement and disengagement being provided by a catch and an abutment, said catch being movable with trigger movement and said abutment being stationary with said housing; said catch and said abutment being located so that said spring bias causes automatic engagement between said catch and said abutment whenever said trigger is returned to its off position to prevent accidental operation of said switch; and a release button mounted on said housing and being depressible to separate said catch from said abutment to allow operation of said trigger to its on position.

Claim 10

A trigger switch for a portable electric tool affording intended operation thereof but automatically locking it against accidental operation whenever the switch is released comprising; a housing for the switch mechanism; a trigger mounted on said housing for limited reciprocal movement between an on position wherein the switch is in operation and an off position wherein the switch is not in operation; a return spring normally biasing said trigger into its off position; and an automatically engaging off lock for said trigger including; a spring-biased locking member coupled between said housing and said Trigger, being mounted to and movable with the trigger and being engagable and disengagable with respect to the housing, engagable to lock the trigger against movement with respect to the housing and disengagable to allow trigger movement with respect to the housing; said engagement and disengagement being provided by a catch and an abutment, said catch being movable with trigger movement and said abutment being stationary with said housing; said catch and said abutment being located so that said spring bias causes automatic engagement between said catch and said abutment whenever said trigger is returned to its off position to prevent accidental operation of said switch; and a release button mounted on said housing and being depressible to separate said catch from said abutment to allow operation of said trigger to its on position.

Claim 11

In combination with a portable tool having a handle to be grasped by the right hand of the user, an aperture in the front of the handle for a trigger and a hole in the left side of the handle for an off lock release button; a self-enclosed trigger switch mounted within said handle comprising; a housing for the switch mechanism; a trigger mounted on said housing for limited movement between an on position wherein the switch is in operation and an off position where the switch is in operation; said trigger extending out of said aperture for depression by the forefinger of the user; a return spring normally biasing said trigger into its off position; and an automatically engaging off lock for said trigger including; a spring-biased locking member between said housing and said trigger, being unitarily associated with said trigger with the spring being between said locking member and said trigger and being engagable and disengagable with respect to said housing, engagable to lock the trigger against movement with respect to the housing and disengagable to allow trigger movement with respect to the housing; said engagement and disengagement being provided by a catch and an abutment, said catch being movable with trigger movement and said abutment being stationary with said housing; said catch and said abutment being located so that said spring bias causes automatic engagement between them whenever said trigger is returned to its off position to prevent accidental operation of said tool; and a release button mounted on said housing and extending out of said hole in said handle to be depressible by the thumb of the user to separate said catch from said abutment to allow operation of said tool.

Claim 12

In combination with a portable tool having a handle to be grasped by the right hand of the user, an aperture in the front of the handle for a trigger and a hole in the left side of the handle for an off lock release button; a self-enclosed trigger switch mounted within said handle comprising; a housing for the switch mechanism; a trigger mounted on said housing for limited movement between an on position wherein the switch is in operation and an off position where the switch is in operation; said trigger extending out of said aperture for depression by the forefinger of the user; a return spring normally biasing said trigger into its off position; and an automatically engaging off lock for said trigger including; a spring-biased locking member between said housing and said trigger, being unitarily associated with said trigger with the spring being between said locking member and said trigger and being engagable and disengagable with respect to said housing, engagable to lock the trigger against movement with respect to the housing and disengagable to allow trigger movement with respect to the housing; said engagement and disengagement being provided by a catch and an abutment, said catch being movable with trigger movement and said abutment being stationary with said housing; said catch and said abutment being located so that said spring bias causes automatic engagement between them whenever said trigger is returned to its off position to prevent accidental operation of said tool; and a release button mounted on said housing and extending out of said hole in said handle to be depressible by the thumb of the user to separate said catch from said abutment to allow operation of said tool.