Improvements in Electrical Pushes and Contacts therefor.
Year: 1897

page_text: Date of Application, 15th June, 1897
Complete Specification Left, 14th Mar., 1898-Accepted, 23rd Apr., 1898
PROVISIONAL SPECIFICATION.
Improvements in Electrical Pushes and Contacts therefor.
We, MAX BYNG, Electrical Engineer, and VALENTINE HOLT, Electrician, both
of No. 71, Queen Victoria Street, in the City and County of London, do hereby de-
clare the nature of this invention to be as follows:—
Our invention relates to certain improvements in electrical pushes and contacts
therefor, and has for its objects firstly, a rubbing contact which may be by usage
free from oxidation or the accumulation of dust or dirt which may prevent pro-
per contact, and secondly a better mechanical action than has heretofore been
used. The invention applies especially to plunger pushes or contacts in which
a considerable range of surface for guiding the moving parts and facilitating
a parallel action is afforded.
In carrying our said invention into practice, we construct a tube, or frame
of circular or semicircular cross section, having a flange at one end for attachment
to the place where it is to be used. Within said tube or frame we place a
plunger, with an ordinary press or push button at the end, projecting beyond the
Hange aforesaid. Said plunger is provided with a collar, or shoulder, against
which a spiral or volute spring is arranged to keep it in a normal or out of con-
tact position when in tension. An insulating, or insulated cap, is fitted to the
opposite end of the tube or frame, and two or more bent spring brushes are
attached thereto, and form in themselves, and by connection with the external electri-
cal circuit the contacts. When the plunger is pressed into the tube or frame against
shaped,
the tension of the spring, the end of said plunger being properly
forces said brushes apart, at the same time cleaning both surfaces, and producing
a proper electrical contact.
We may vary the external construction or conformation of the device, but
in all cases retain the essential feature according to our invention, viz.; the scrap-
ing contact formed by the parting of the spring brushes by the end of the plunger
aforesaid.
FREDK. WALKER.
73, St. Stephen's Road, Upton Park, E.,
Agent for the Applicants.

page_text: 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:
Our invention relates to certain improvements in electrical pushes, and contacts
therefor, and has for its objects, firstly, a rubbing contact which may be by usage free
from oxidation or the accumulation of dust or dirt, which may prevent perfect elec-
trical contact; and secondly; a better mechanical action than has heretofore been
used. The invention is especially applicable to plunger pushes or contacts in which
a considerable range of surface for guiding the moving parts and facilitating
a parallel action is afforded.
In order that our invention may be clearly understood we have appended the
accompanying sheet of drawings, in which Figure 1 is an end elevation of a barrel
push, and Figure 2 a longitudinal section of the same, and Figure 3 a back
elevation, also corresponding to the former views Figure 4 is a detached view
illustrating the chief point of the invention. Similar letters of reference in-
dicate like parts throughout the several views.
In carrying our invention we employ a tube A, of circular or semicircular
cross section, or a skeleton frame as a substitute therefor, having a flange B
at one end for attachment to the place where it is to be used. Within said tube
or frame A is placed a plunger C, with an ordinary press button end c pro-
jecting beyond B. Said plunger C is arranged to slide freely within A, and is
provided with a collar or shoulder abutting against a spiral spring S in tension
against a fixed plate D, through which the plunger C passes, this forming a second
guide, and also a stop for the spring. The action of said spring S is to keep the
push normally out of contact. An insulating cap E is fitted to the opposite end
of the tube or frame A relatively to the flange B and has attached to its inner
surface two bent spring contact brushes, bb'. Upon the outer surface of E are
two contact plates and terminals t¹ connected to the brushes b¹. The end e
of the plunger C is shaped so as to complete the electrical circuit when pressed
between the brushes 66', forcing them apart, and at the same time cleaning
them and under all atmospheric and other conditions securing a perfect electrical
contact. The detached view Figure 4 shows this essential feature of our said
invention. We may employ more than one pair of spring brushes if necessary,
properly connecting these to act as a single pair or for multiple circuits, which
would have the same connection with an increased contact surface.
Having now particularly described and ascertained the nature of our said in-
vention and in what manner the same is to be performed, I declare that what
we claim is:
First. In a barrel or frame push for electrical purposes, the arrangement of
parts and construction thereof substantially as herein described and for the pur-
poses stated, with reference to the appended drawings.
Second. In a push for electric circuits the combination of a contact knob or
pin e with two or more spring contact brushes, substantially as herein described
with especial reference to Figure 4 of the appended drawings.
The 10
1
L 1000
FREDK. WALKER,
73, St. Stephen's Road, Upton Park, London, E.,
Agent for the Applicants.