Improvements in Door-locks or Latches.
Year: 1893

page_text: Date of Application, 4th Aug., 1893-Accepted, 30th Sept., 1893
COMPLETE SPECIFICATION.
Improvements in Door-locks or Latches.
I, JOHAN MATHISEN, of 6 Calmeyergaden, Christiania, in the Kingdom of
Norway, Mechanician, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
My invention relates to spring-locks or latches for doors and it consists in
arranging the springs in such positions relatively to each other that friction is
reduced to a minimum, the springs being connected to a lever which acts upon the
bolt in such a manner that the bolt ensures a secure fastening of the door. The
door handle is easily operated and an arrangement is provided whereby it can be
readily adjusted.
The lock can be manufactured at a small cost, works with a minimum amount
of wear on account of the small amount of friction and never requires to be oiled.
My invention is illustrated in the accompanying drawing, in which :-
Figure 1 is an elevation of a door-lock embodying my improvements, the handles
and their spindle being removed:
Figure 2 is a section of part of the same with the handles, the section being
taken on the line y of Figure 1 ; and,
Figure 3 is an elevation of part of a modified construction of lock or latch.
Referring first to Figures 1 and 2 a is the lever which turns in the sides of the
lock-case, its free end being jointed to the handle bolt b while the other end is
formed with the usual square hole e to receive the handle spindle. The lever a is
provided with two lugs d, d, to which the spiral-springs e, e are attached by one of
their ends in any suitable manner for example as shewn in Figure 1, where the end
of the spiral-spring is bent over the lug d and enters a hole in the said lug so that
friction and wear only take place at the extreme end of the spring where it is
placed in the hole. The other end of the said spring is suitably attached to the
lock-case, the springs being approximately placed in the positions relatively to
each other shewn in Figure 1 or Figure 3, or three of such springs may be
employed. It is evident that the strain equalized when the lever a is turned by
the handle as the springs e are all of equal tension and balance each other in such
a manner as to enable the handle to be easily turned; at the same time the springs
will act strongly on the bolt e, when the door is closed, so that the bolt secures the
door well and exactly.
In the arrangement shewn in Figure 3 the bolt b is provided with a third spring y
which assists in keeping the bolt in a locking position, the lever acting loosely upon
a flange on the bolt b.
In order to regulate the handles in case they should become loose I connect one
handle to a spindle adapted to enter a sleeve to which the other handle is fixed,
a screw i passing through a slot h into the spindle so as to keep the handles in the
position to which they may have been adjusted.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. In door-locks or latches the arrangement of a lever, one end of which acts
upon the handle bolt and the other end is formed with a square to receive the
handle spindle, the said lever turning in the lock-case and being combined with
two or more spiral-springs in such a manner that an equal balanced strain is
obtained, substantially as described.

page_text: 2. In door-locks or latches the herein described arrangement for adjusting the
handles by means of a slot and a screw, substantially as set forth and for the
purpose described and as illustrated in Figure 2 of the accompanying drawing.
3. The improved door-locks or latches hereinbefore described and illustrated in
Figures 1 and 2 and Figure 3 of the accompanying drawing.
Dated this 4th day of August 1893.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant