Heat responsive door latch handle
AssigneeBaldwin Hardware Manufacturing Corporation
InventorsPeter Fayerman, Elwood Shaffer
Life of this patent
Estimating the term…
Abstract
A door latch mechanism for controllably securing a door, the latch mechanism of the type having a spindle and operating handles, comprises a fusible connecting member rigidly attaching the handle and spindle at room temperature, the fusible connecting member melting at elevated temperatures to permit relative rotation of the handle and spindle. The handle is mounted using a connecting member which is attached to the latch trim using a screwless connection. This is particularly applicable to latches using lever handles in that a positive positioning mechanism holds the handles at their selected positions, regardless of wear and age.
Claims13
A fusibly-linked latch mechanism for controllably securing a door, the latch mechanism having a shaft, the latch mechanism being operable by moving said shaft, said latch mechanism comprising:
- a handle having an opening, said handle mounted on the shaft for actuating the latch mechanism;
- and
- a fusible link member disposed within the opening, between the handle and the shaft, the fusible link member being of a material which melts at an elevated temperature to permit relative movement between the handle and the shaft, the fusible link member contacting the shaft and handle, and being sufficiently thin that capillary action retains a portion of the material in position when melted, whereby the handle is temporarily disengaged from the latch mechanism by elevated temperature.
A fusibly-linked latch mechanism for controllably securing a door, comprising:
- a handle to be grasped for rotation, the handle being bored along an axis defined by said rotation to form a cylindrical bore;
- a spindle rotatable to effect operation of the latch mechanism, the spindle having a non-cylindrical external surface;
- and
- a connection member having a cylindrical outer surface slightly smaller than the bore of the handle and a non-cylindrical cavity fitting securely over the spindle, the connection member being attached to the handle by an annular layer of fusible material disposed within the cylindrical bore between the handle and the connection member, and being sufficiently thin that capillary action retains a portion of the fusible material when melted.
Dependencies are inferred from the claim text.