Improvements in Constant Upward-pressure Contact for Overhead Conductors.
Year: 1889

page_text: being date of first Foreign Application (in
United States of America),
Date of Application (in United Kingdom), 15th Jan.,
9th Aug., 1888
1889
Complete Specification Left, 15th Jan., 1889-Accepted, 10th Aug., 1888
COMPLETE SPECIFICATION.
Improvements in Constant Upward-pressure Contact for Overhead
Conductors.
I, CHARLES JOSEpi Van Depoele, residing at Number 57 Center Street, in the
City of Lynn, County of Essex and State of Massachusetts, one of the United States
of America, Electrician, 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 improvements in Electric Railways, more particularly to
that feature thereof which comprises the traveling connection between the moving
car and a suspended supply-conductor.
The main feature of the invention comprises a contact-carrying arm of novel
design and means for maintaining an upward contact of constant pressure between
the contact device at the extremity thereof and the undulating under side of the
suspended conductor.
The details of my improvement will be hereinafter fully set forth, in connection
with the accompanying drawings, in which—
Figure 1, is an elevation showing a portion of the top of an electric-railway car
and my improved contact-arm in operative position thereon.
Figure 2, is an end view of the contact-arm and tension-springs.
Figure 3, is a view in elevation with the contact-arm in different positions, the
contact-arm itself being shown as without the flexible portion.
Figure 4, is an elevation showing the relationship of the tension devices in another
different position.
Figures 5 and 6, are respectively, an elevation and an end view of a different form
of compensating device.
As seen in the drawings, upon the top of the car, A, centrally, or in any other
desired position, is mounted upon a suitable thickness of insulation a metallic post, B,
which is provided with an extended base, b, between which and the metallic roof of
the car is interposed a suitable thickness of insulation, C. Upon the post, B, is
placed a rotatable and removable sleeve, B¹, to the upper end of which is secured a
fork, D, which latter is thus pivotally supported upon the post, B, and capable of rotary
movement thereon to any desired extent. A vertically-adjustable collar, C¹, is also
secured upon the exterior of the sleeve, B, and provided with a projection, C, as will
appear.
E, is the contact-carrying arm, which is constructed of a number of light metallic
rods or wires, e, united at suitable distances by stay-plates, F. The outer extremities
of the rods, e, are permanently secured to a collar, or to the shank of a fork, G,
between the prongs of which is journaled or otherwise mounted the contact-wheel or
device, H. The lower extremities of the rods, e, are likewise similarly attached to a
block, I, which may be formed integral with or be subsequently attached to an
elliptical or sloping cam, J, or to an eccentric which is pivotally mounted between the
extremities of the fork, D, with the extended portion of the cain projecting rearward
and upward, the arm being thus universally movable upon its support. To the

page_text: projection, C, of the vertically-adjustable collar, C¹, are attached the lower
extremities of tension springs, K, the upper extremities of said springs being
connected to a band, M, engaging the face of the cam, J, and firmly secured at its
highest point.
The tension of the springs, K, acting through the baud, M, tonds to elevate
the extremity of the contact-carrying arm, E, and thereby to hold the contact, H,
against the under side of the supply-conductor, P. Great difficulty has heretofore
been experienced in maintaining said contact with good operative effect, for the
reason that as it is impracticable to suspend the conductor, P, in a perfectly horizontal
line at the same distance above the track in all places, the tension-spring heretofore
used by me was either required to be unnecessarily strong, in order to elevate the
contact-wheel as much as might in some cases be desired, or else its range of effective
movement was too limited. By my present invention, however, all these objections
are overcome.
The radius of the cam, J, as seen in Figures 1 to 4, is that of the involute of a
semi-circle, otherwise known as an "Archimedoau spiral," and it increases in diameter
toward its upward part in proportion to the loss of power by the tension-springs
in contracting that is to say, as the springs, K, elevate the outer ond of the contact-
arm and become weaker their operative leverage upon said arm is increased by the
increased radins of the cam, J, so that the effect of said springs upon the contact-arm
and the pressure with which said contact is held up against the conductor is practically
uniform throughout its entire range of movement.
The radius of the cam, J, will not be the same under all circumstances, and whore
the contact-arm is made heavier, or the contact-wheol varied in size, or the contact-
arın made longer or shorter, cams of suitably-different radii are provided, or the cam
is made adjustable or in the form of an eccentric and provided with means for
adjustment to the service required.
As shown in Figure 5, an eccentric, J¹, may be substituted for the cam, J. The
eccentric is mounted in the fork, D, and the shauk, d, of the contact-arm is also
supported upon the same pivot. The shank or lower end of the contact-arm is
secured to the eccentric by an adjustable connection-as, for example, by the curved
brace arm or arms, or by the bolt, d, moving in a curved slot in the eccentric and by
which the arm is bolted or clamped in desired relation to the eccentric, J. The
band, M, may be attached at different points upon the faco of the eccentric by a
inovable screw-bolt, or directly to the shank of the arm, as by link, j.
As other means of adjustment will be obvious in view of the foregoing, the form
illustrated will suffice.
Theoretically, a single tension-spring attached at one end to the extension, C³, of
the adjustable sleeve, C¹, and at its other to the band, M, would suffice; but in
practice it is found that a bunch of springs-containing, for example, five-all of
much lighter wire, will produce the desired effect in a more satisfactory manner than
the single heavy spring referred to, and, furthermore, be much more easily handled
both for adjustment and in construction. I have therefore shown, a bunch of
springs, as indicated by the letter, K, the lower extremities of which are hooked
into a cross-plate, L, said cross-plate being bolted to the projection, C². The upper
ends of the springs, K, are similarly secured to a cross-plate, l', connected to the
band, M.
In Figures 1, 2 and 3, the arm is seen at different elevations, from which the
difference in leverage in the different positions will be apparent. A stop, L, is
formed or attached to the cam, J, and constructed to engage the fork, D, to
limit the movement of the arm and prevent the tension-springs from throwing it
over backward, in case the contact devico should become accidentally detached from
the conductor.
The contact-arm, as just described, is a perfectly rigid structure, and as such
embodies one form of my invention. For many purposes, however, it is advantageous
to construct the arm so that a part at least thereof, desirably the outer end portion,
shall be flexible. Each component member of the arm consists, as stated, of a thin

page_text: metallic rod possessing considerable elasticity, but rigidly secured in the cross-plates, F.
When all the rods are rigidly secured in the cross-plates, as seen in Figure 3, the
structure as a whole is practically rigid; but in the form shown in Figure 1, a central
rod, e¹, carrying the contact, H, at its outer extremity, is added. The rod, e', passes
loosely through the outer place, and may also project beyond said plate for a length of
one or two feet. It is rigidly secured in the next cross-plate, and may terminate
there or extend the entire length of the arm and be secured in block, I. This
arrangement, while allowing the end portion to bend freely, will impart a very useful
degree of flexibility to the contact-supporting device, which will materially lessen its
tendency, if any there be, to jump or spring downward from the wire when making
switches or in passing any obstruction or obstacle that may be encountered.
It will be understood that the cain, J, or its equivalent, constitutes a distinct feature
of invention, irrespective of the construction of the arm used in connection therewith,
and that the arrangement of the tension springs or devices might be materially
modified without departing from the invention.
It will be understood, moreover, that various minor modifications and changes
may be made in the structure herein shown and particularly described by way
of illustration, and I therefore do not limit myself to the precise details set forth.
In the foregoing I have described a sloping cam or an adjustable eccentric as
a means of imparting constant upward pressure to the contact-carrying arm. In
using the term " cam I intend to include both these features or anything equivalent
thereto.
"
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. An upward-pressure contact for electric railways comprising the combination,
with a universally-movable arm, of a sloping cam attached thereto, and a tension-
spring connected with said cam and acting to exert a practically constant force
upon said arm throughout its operative range of movement, substantially as
described.
2. An upward-pressure contact for electric railways, comprising the combination,
with a movable arm carrying a contact device at its outer extremity, of a cam at its
lower extremity, and a tension-spring connected with said cam and acting to exert n
practically constant upward pressure upon the outer extremity of said arm throughout
its operative range of movement, substantially as described.
3. An upward-pressure contact for electric railways, 'comprising the combination,
with a movable arm, of a cam adjustably connected thereto, and a tension-spring
connected with the cam and acting to exert a constant force upon said arm throughout
its operative range of movement substantially as described.
4. An upward-pressure contact for electric railways, comprising the combination,
with a hinged arm carrying a contact at its outer extremity, of an adjustablo
cam connected to its lower extremity, a spring connected to said cam for imparting
upward movement to the contact-carrying arm, and movable clamping devices for
connecting the arm and cam or eccentric in any desired relation substantially as
described.
5. An upward-pressure contact for electric railways, comprising the combination,
with a hinged arm carrying a contact at its outer end, of a cam at its lower extremity,
and a tension-spring connected to said cam and acting to press the outer end of the
contact arm upward with a constant pressure throughout its operative range of
movement, substantially as described.
6. An upward-pressure contact for electric railways, comprising the combination,
with a hinged arm carrying a contact at its outer end and a sloping cam at its lower
extremity, of a tension-spring connected to said cam, whereby as the tension of the
spring decreases with the elevation of the arm its leverage thereon will be increased,
substantially as described.
7. An upward-pressure contact for electric railways, comprising the combination

page_text: with a hinged arm, of a hinge support for the lower end thereof, an eccentric also
mounted upon said support and adjustably connected to the arm, and a tension-spring
connected to the face of the eccentric for imparting upward movement to the outer
portion of the arm, substantially as described.
8. An upward-pressure contact for electric railways, comprising the combination of
a hinged arm carrying a contact at its outer extremity, the cam, J, at its lower
extremity, the tension-spring, K, and a flexible connection extending from the spring
and engaging the face of the cam, substantially as described.
9. An upward-pressure contact for electric railways, comprising the combination of
a contact-carrying arm, a sloping cam at its lower extremity, a tension-spring
connected to the face of the cam for imparting upward motion to the outer extremity
of the arm, and a fixed support and a movable support sustained thereon, and carrying
the arm, cam and tension-spring, substantially as described.
10. A contact-carrying arm mounted upon a hinged-support and having a flexible
end portion, to which the contact device is secured, substantially as described.
11. A contact-arm composed of side rods secured in cross-plates and forming a
rigid structure, and a flexible end rod centrally disposed and secured in one of
the plates and passing loosely through the end plate and carrying the contact device,
as described.
12. The combination of an arm carrying a contact at its outer extremity and a cam
at its inner end, a fixed support, B, a tubular support rotatably mounted thereon and
hinged at its upper extremity to the lower part of the contact-arm, a tension-spring
connected to and acting upon the face of the cam, and a support for the tension-spring
adjustably mounted upon the rotatable support.
13. An upward-pressure contact for electric railways, comprising the combination
of the hinged arm, the cam, the tension-spring connected to the cam for imparting
upward movement to the outer portion of the arin, and a stop for limiting said upward
movement, substantially as described.
14. A contact-arm composed of a truss having a flexible rod.secured in its end
portion and carrying a contact device at its outer extremity, substantially as
described.
15. A contact-arm mounted upon a hinged support and having a portion of its
length rigid or semi-rigid, and a flexible whip-like end, to which the contact-trolley is
secured. substantially as described.
Dated this 15th day of January 1889.
CHARLES JOSEPH VAN DEPOELE.
By Jensen & Son,
77, Chancery Lane, London, W.C., Patent Agents.