Improvements in Electrical Devices for Releasing Doors.
Year: 1893

page_text: Date of Application, 26th Aug., 1893-Accepted, 14th Oct., 1893
COMPLETE SPECIFICATION.
Improvements in Electrical Devices for Releasing Doors.
A communication by HERMANN SCHÜTZE, of Würzburg, in the Empire of
Germany, Mechanic.
I, WILLIAM PHILLIPS THOMPSON F.C.S. M.I.M.E. of the Agency for
Foreign Patent Solicitors 6, Lord Street, Liverpool and 6, Bank Street,
Manchester, both in the County of Lancaster and 323 High Holborn in the
County of Middlesex, Civil Engineer do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
This invention has for its object an electrical door opener which is shown on the
accompanying drawing-
Figure 1 being an elevation, and
Figure 4 a section on the line A B, Figure 1:
Figures 2 and 3 being section and front view respectively of a nut a.
The parts consist essentially of an electro-magnet with an armature, of a catch
device and of a latch bolt.
These parts are inserted in a suitable case, and the latter is let into the side post
of the door. The catch, which has the form shown in the drawing, moves in
suitable supports in the case, and is, by means of a spring m, drawn in the direction
indicated by the arrow I, Figure 4. The catch f, when the parts are at rest, rests
behind the spring fastening bolt arranged in the door, the projection f¹ of the
catch engaging at the same time behind the projection n, Figure 2, of a bolt r.
The latter is let into the nut a, which is preferably pivotted eccentrically, and
revolves in suitable holders in the case, and, when the device is at rest, engages by
means of its wing a' behind the armature lever h of the electro-magnet, such lever
being pivotted at h', or is held (by means of a spring d which draws the nut of the
catch device in the direction shown by the arrow II), behind the armature lever
against a contact piece of the lock case.
The parts act as follows:-
1f, by pressing on a key, the circuit of the current circulating through the
electro-magnet be closed, the armature h is thereby attracted and the way left
open for the movement of the wing a' of the nut a hereinafter more particularly
described.
The door is opened whilst the circuit is closed (in the direction of arrow III,
Figure 4), the door catch of the electrical door opener being turned out of the
position shown in full lines in Figure into the position shown in dotted lines.
By this means, on the one hand, the spring m is distended, and, on the other hand,
the wing simultaneously causes the eccentrically arranged nut a to rotate into
the position shown in dotted lines, thus distending the spring d.
At the same moment as the wing f¹ releases the projection n, the distended
spring d returns the nut a into its original position. If, in the next moment, the
lock latch S releases the door opening catch, the latter, owing to the action of the
spring m, springs back into its first assumed position, the projection n escaping
with a spring action from the wing f'. The whole arrangement thus returns to its
original position.
When the door is closed, the fastening catch S, by means of its inclined part,
slides first along the door opening catch f, which, when at rest, is situated in a
projection of the sheet metal plate of the lock, and then springs behind the door
opening catch as soon as the door has completely entered its recess.
The parts may, of course, be also arranged so that the door opener may be fixed-
to the door and the fastening latch to the door post.

page_text: The following are the advantages offered by this invention :—
1st. The releasing may be performed with a weak current simply because the
electromagnet armature is not loaded; the load on the same is entirely relieved by
the action of the springs m and d (direction of the arrows I and II).
2nd. The catch springs back automatically, after the door is opened, into its
original position without the use of complicated mechanism, such as a lever or
the like.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
An electric door opener having an eccentrically arranged nut a operated by a
spring d, the spring projection n of which nut engages, when in a position of repose,
behind a wing f₁of the latch f, and the wing a' of the same nut also engaging
behind the armature lever, the latter being attracted when the circuit is closed,
so that the door may be opened, whereby the catch turns together with the nut a
thereby causing an immediate automatic springing back of the same into its
original position.
Dated this 25th day of August 1893.
WM. P. THOMPSON & Co.,
Agents for the Applicant.