| 摘要 |
An electric heat sealer comprises a pen-shaped housing including a power supply unit and an end portion, preferably in the form of a tapered socket, containing an electric heat seal unit. The heat seal unit includes a heat sealing tip projecting from an opening in the end portion of the housing. The heat seal unit is movable axially within the housing end portion and includes an electric contact connected to the electric heating element and arranged to engage an electric terminal on the housing to complete an electrical circuit between the power supply unit and the electric heating element. A spring disposed between the one end of the housing and the heat seal unit axially biases the heat seal unit toward the opening in the end portion of the housing sufficiently to separate the contact on the heat seal unit from the terminal on the housing. Axially directed pressure on the heat seal unit tip causes sufficient axial movement against the bias of the spring to cause the contact to engage the terminal to complete the circuit between the power supply unit and the electric heating element. Release of the pressure on the projecting tip causes movement of the heat seal unit under the urging of the spring thereby causing disengagement of the contact and the terminal so as to break the electric circuit. |
