Trigger actuated control having supplemental heat sink
First Claim
Patent Images
1. A trigger actuated control for controlling rotational speed of an electric motor of a portable tool, said control having:
- an electrically insulating housing;
a manually displaceable trigger mounted to said housing;
an electric circuit in said housing comprising a variable resistor operably connected to said trigger and a thyristor connected in circuit with said variable resistance and the electric motor of said portable tool for varying rotational speed of said motor as a function of displacement of said trigger; and
a primary heat sink in said housing thermally coupled with at least said thyristor;
wherein the improvement comprises;
an opening in said housing;
a supplemental heat sink disposed externally of said housing and having a projection extending through said opening into thermally coupled relationship with said primary heat sink; and
complemental attachment means on said housing and said supplemental heat sink for attaching said supplemental heat sink to said housing.
1 Assignment
0 Petitions
Accused Products
Abstract
A heat sink is slideably attached to a housing of an electronic control, retained by complemental snap-in elements and has a projection extending through a wall of the housing into abutting thermal engagement with an internal heat sink which is in intimate contact with the electronics of the control.
30 Citations
10 Claims
-
1. A trigger actuated control for controlling rotational speed of an electric motor of a portable tool, said control having:
-
an electrically insulating housing; a manually displaceable trigger mounted to said housing; an electric circuit in said housing comprising a variable resistor operably connected to said trigger and a thyristor connected in circuit with said variable resistance and the electric motor of said portable tool for varying rotational speed of said motor as a function of displacement of said trigger; and a primary heat sink in said housing thermally coupled with at least said thyristor; wherein the improvement comprises; an opening in said housing; a supplemental heat sink disposed externally of said housing and having a projection extending through said opening into thermally coupled relationship with said primary heat sink; and complemental attachment means on said housing and said supplemental heat sink for attaching said supplemental heat sink to said housing. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
Specification