Improvements in and connected with Electric Door Contact.
Year: 1894

page_text: Date of Application. 18th Oct., 1894
Complete Specification Left, 17th July, 1895-Accepted, 17th Aug., 1895
PROVISIONAL SPECIFICATION.
Improvements in and connected with Electric Door Contact.
1, HERMANN OPPENHEIMER Electrical Engineer of 55 Redcross Street
London E.C. do hereby declare the nature of this invention to be as follows:-
Electric door contacts or triggers are generally so constructed that on opening
the door, the contact piece is pressed against the contact spring, thus closing the
circuit, and actuating the electric bell, thereby giving the signal.
The same signal however, is given when the door is closed again, and in order
to avoid this second signal, I have constructed a one-way contact, which I will now
describe.
In Fig. 1, I show a side view of the one-way door contact. From an angle
piece RI suspend at point S a curved frame, consisting of two parts, joined
together by studs, one of which forms the axis at S on which they move, while the
frame when in normal position rests against R at point d (Fig. 1). Between the
two parts of such frame D, there is a roller r, whose axis A is supported by
the perforation S. shown in the frame, and which allows the roller to move
backwards and forwards.
The stud between the two frame plates D has a platinum contact c while the
platinum pointed spring f, which is insulated from, and fixed to the top of the
angle picce carries one terminal. The other terminal V, which I show in Figs. 1
& respectively, is connected to the metal angle piece.
The fixing of the spring fis shewn in Figs. 3 & 4, the latter shewing section
of a. b.
Fig. 2. shows the contact in front view, with contact spring detached. The oue-
way contact is screwed to the top of door-post, and when the door is opened it
touches the roller r, thereby raising the movable frame, and bringing platinum
point c into contact with platinum point on spring f, thus closing the circuit. On
shutting the door, it again touches roller r, which however moves backwards in
perforations thereby allowing the door to close without raising the frame.
latter case, the roller only is raised, but not the frame plates.
London, dated this 17th day of October 1894.
In the
Improvements in and connected with Electric Door Contact.
I, HERMANN OPPENHEIMER 55 Red Cross Street, London E.C., Electrical
Engineer 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 :-
Door contacts or door triggers are generally so constructed that on opening the
door the contact piece is pressed against the contact spring, thus closing the circuit
& actuating the electric bell, thereby giving the signal.
The same signal is however given when the door is closed again, and in order
I Prima Q1

page_text: to avoid this second ringing, I have constructed a one way door contact, which I
will describe by the aid of the drawing referred to & filed with my Provisional
Specification No. 19807 Oct. 18/94.
In Fig. 1, I show a side view of the one way contact. From an angle-piece R
I suspend a sledge piece D consisting of two parts connected together.
The sledge piece D is hinged to the angle piece rat point S, so as to allow of
its being moved up and down.
Between the 2 parts of such sledge piece D, held apart by the cross piece d,
hinge S, and connecting piece c, there is a roller r, which with its axis A rests on
the perforations shown in the sledge piece, and which allows the roller to move
backward and forward.
The connecting piece between the 2 plates D has a platinum contact c, while the
spring, which is insulated at point v, from, and fixed to angle piece Ŕ, has also
a platinum point.
The fixing of the spring f is shown in plan in Fig. 3, a. b., while Fig. 4
represents the section. Fig. 2. shows the contact in front view with detached
contact spring.
The one way contact is screwed to the top of the door post, and when the door
is opened, it touches the roller r, thereby raising the sledge piece D, and bringing
platinum point c into contact with the platinum point on spring f.
On closing the door, it touches again roller r, which however moves backward,
thereby allowing the door to close without the contact points touching.
In the latter case only the roller is raised, but not the sledge piece D.
?"
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
In a one way door contact, the construction, use, and arrangement of a hinged
sledge piece with sliding roller substantially as described, and for the purpose as
set forth.
Dated this day 16th July 1895.
HERMANN OPPENHEIMER.