Lead-in device for aiding the installation of rim-type lock cylinders

An insertable lead-in device for use with a lock cylinder to be installed into an exit mechanism, the lock cylinder of the type having a movable tailpiece, and the exit mechanism of the type including a rotatable cam having a cam aperture with an effective capture area for receiving the tailpiece therein, wherein the insertable lead-in device comprises:

• means for increasing the capture area of the cam aperture to facilitate insertion of the tailpiece into the cam aperture to couple the lock cylinder to the exit mechanism, and coupling means for coupling the means for increasing the capture area to the cam so that said means for increasing the capture area is rotatably driven by said cam, said coupling means including first and second flexible arms, each arm attached at its proximal end to said means for increasing the capture area and insertable into the cam aperture so as to position the means for increasing the capture area adjacent the cam aperture, and each arm having attached thereto at its distal end a means for retaining the means for coupling in position,
• wherein the means for increasing the capture area includes a plurality of walls arranged to define a converging rectangular conduit having an entrance aperture at one axial end and an exit aperture, smaller than the entrance aperture, at an opposite axial end, the exit aperture being substantially similar in shape to a portion of a cam aperture into which a tailpiece is received.

An insertable lead-in device in combination with a lock cylinder having a movable tailpiece, and an exit mechanism including a cam having a mating aperture for mating with and receiving the tailpiece therein, the insertable lead-in device comprising:

• a plurality of walls arranged to define a converging conduit having an entrance and an exit, said entrance being larger than said exit and generally perpendicular to a longitudinal axis of said lead-in device;
• and
• a pair of arms extending from a surface surrounding the exit, insertable into the mating aperture, each arm including a finger disposed to position the exit of the conduit adjacent the aperture,
• wherein:
• said mating aperture comprises two orthogonal rectangular slots which bisect each other, a first of said slots receiving said tailpiece and a second of said slots receiving said arms.