United States Patent 3806171

A multiple dead-bolt lock which is mounted in a door frame, said bolts located so as to fit locking recesses mounted in the door. Each dead bolt is faced with an internal rack oriented parallel to the axis of travel of the dead-bolt, the rack mating with a pair of spur gears which are rotatably driven by gears meshing with one flexible shaft which may be rotated by the master locking cylinder, or by a motor operated by a remote control mechanism.

Application Number:
Publication Date:
Filing Date:
Primary Class:
International Classes:
E05C9/08; E05B47/00; E05B63/00; (IPC1-7): E05C9/04; E05C9/12
Field of Search:
View Patent Images:
US Patent References:
1577335Safe lock1926-03-16Mariotti

Foreign References:
Primary Examiner:
Larkin, Geo V.
Attorney, Agent or Firm:
Podell, Howard I.
Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is

1. A multiple dead-bolt lock assembly which is mounted in a door frame to which a door is hinged, said assembly comprising a series of dead-bolts, mechanically linked together, with


This invention relates to a multiple dead-bolt lock mounted in the frame of a door, and designed to lock with mating recesses in the door.

An advantage of this invention lies in the fact that the dead-bolt mechanisms are linked by a flexible shaft, permitting the axes of the dead-bolts to be angularly aligned with each other.

In my invention, the dead-bolt is in the form of an L shaped member, with a toothed rack internal surface such that the axis of the rack is parallel to the axis of travel of the dead-bolt. A pair of spur gears are mounted so as to mate with the dead-bolt rack; each of said spur gears being meshed with a gear fastened to the central shaft. The central shafts of each dead-bolt lock assembly are rotatably fastened together by means of a flexible drive shaft.

The flexible drive shaft may be rotated by motorized means in the door frame, or by a locking cylinder operated by a key, said locking cylinder being rotatably joined to said flexible shaft.


The objects and features of the invention may be understood with reference to the following detailed description of an illustrative embodiment of the invention, taken together with the accompanying drawing in which:

FIG. 1 is an elevation view of the multiple dead-bolt lock assembly engaged in a door;

FIG. 2 is a cross-section of the multiple dead-bolt lock assembly taken at line 2--2 of FIG. 1; and

FIG. 3 is a plan view of the drive gear assembly taken at line 3--3 of FIG. 2.


Turning now descriptively to the drawing, in which similar reference characters denote similar elements throughout the several views, FIG. 1 illustrates a door 19 locked by dead-bolt assemblies 10U, 10C and 10L mounted in the door frame 29.

As shown in FIG. 1 and FIG. 2, the individual dead-bolt assemblies 10L, 10C and 10U are of similar construction and will be referred to in this description as dead-bolt assembly 10. They are joined together by flexible shaft 26, which joins and rotates lock shaft 25 in each dead-bolt assembly 10. The dead-bolts 18 fit into female recesses 31 of the latch housing 22 in the door, when the dead-bolts 18 are set in the locking mode. Flexible shaft 26 may be rotated by a key operated locking cylinder, mounted in the mechanism of dead-bolt assembly 10C, or as shown in FIG. 1 and FIG. 3, shaft 26 is rotated by motor 33 that is regulated by remote control unit 34.

As shown in FIG. 2 and FIG. 3 each lock shaft 25 is fastened to, and rotates spur gear 60 which is in mating engagement with both spur gears 13 mounted on shafts 12 in each dead-bolt assembly 10.

As shown in FIG. 2, spur gears 13 engage the teeth 14 of the internal rack surface of dead-bolt 18, causing dead-bolt 18 to travel in or out of recess 31 of door latch 22. Travel of the dead-bolt 18 is limited by stop 15 attached to the dead-bolt 18. Stop 15 travels in slot 16 of dead-bolt frame 17. As shown by the dotted lines, in the locked position, dead bolt 18A is engaged in recess 31 of door latch 22.

Flexible shaft 26 which links the lock shafts 25 of each dead-bolt assembly 10 may be rotated by a motor drive unit 33 located in the door frame 29 or adjoining wall area. The motor drive unit 33 is operated by remote control mechanism 34 located at any convenient and safe location.

Since obvious changes may be made in the specific embodiment of the invention described herein, it is indicated that all matter contained herein is intended as illustrative and not as limiting in scope.