Improvements in Sash Balances.
Year: 1890

page_text: Date of Application, 7th Jan., 1890-Accepted, 8th Feb., 1890
Improvements in Sash Balances.
A communication from JAMES MCARTHUR, of the City of Rochester, County of
Monroe, in the State of New York, United States of America, Inventor..
I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex, M.I.M.E.,
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:-
This invention relates to that class of sash balances in which the sash is suspended
from a rope or cable, and in which the tension of a spring replaces the weights
commonly used, and the improvements consist mainly in using an auxiliary pulley
over which the rope or cable passes, in placing the brake so as to act upon the
auxiliary pulley and in providing a guard for protecting the rope or cable passing
over said pulley.
In the drawings figure 1 is a side elevation and Fig. 2 a rear view of one form
of this device; figs. 3 and 4 are respectively a side elevation and front view of
another form of the device; figs. 5 and 6 are respectively a side elevation and an
end view of the guide pulley and frame used in figs. 1 and 2 ; figs. 7 and 8 are
respectively a side elevation and top view of the guide pulley and frame used in
figs. 3 and 4; fig. 9 is a sectional view of the drum and spring. used in this
device.
Into.
The
A is the face plate of the sash balance, to which all the other parts are attached,
and which is led into the window frame so that its outer surface is flush with the
face of the frame, and then secured in position by screws or nails through the
holes provided in the face plate for that purpose. Projecting up from the back
of the face plate are the two side pieces B B provided with the notches a.
these notches fit the ends of the shaft 6 upon which the drum C revolves freely.
This drum contains a spiral spring c c of ordinary construction which is held
securely on the shaft at one end and on the inside of the drum at the other, by
any of the usual devices. There are two flanges projecting from the sides of the
drum and its surface may be left smooth, or may have a continuous groove
formed in it in which the cable or rope can run. One of the ends of the cable D
is securely attached near one of the flanges to the surface of the drum and then
winds around the drum, passing thence over the swinging guide pulley E, and
having its other end attached to the sash by any of the ordinary means.
pulley E projects beyond the surface of the plate A through a suitable slot provided
in said plate and to such a distance as to allow the cable D to clear the surface
of plate A. This pulley is placed on a shaft which is mounted in the frame F
and this frame is so held as to be able to swing in order to accommodate the cable
which unwinds from the drum at continuously varying angles while keeping its
direction and location substantially constant after leaving the pulley E.
swinging of the frame F and thereby of the pulley E may be accomplished in
a number of different manners, but I have only illustrated the two constructions
which are preferred. In figs. 1, 2, 5 and 6 F is the frame carrying the pulley E.
At its upper end it has a projecting lug. A guard G so shaped as to cover the
portion of the cable D on the guide pulley is securely attached to the back of the
face plate A and has a pin di passing through it and the upper lug of the frame F.
At its lower end the frame F has another lug projecting from it, which is held to
a corresponding lug on the back of plate A by a pin d. These two pins d d¹ are
located in line with each other and close to the back of face plate A thus enabling
the frame F to swing around them in a plane at right angles to the surface of plate A.
In figs. 3, 4, 7 and 8 the frame F has the guard G attached to it and projecting
beyond the pulley E at one end, while a lug is formed at the same end parallel with
This

page_text: the face of plate A to which it is held by the pin e passing through the plate and
the lug. In this case the frame swings in a plane parallel to the surface of plate A
around the pin e.
""
It is frequently desirable to vary the tension or draft of the cable D on the sash
to which it is attached and this is accomplished by employing an adjustable brake
to act upon the pulley E. This brake may be applied in various manners but I
have only illustrated the one which is preferred in which the pressure is applied
to the surface of the pulley E by the brake H. In this preferred construction the
brake shoe is carried on a strap of metal which is bent near its lower end so as
to pass through a slot provided in the end of frame F and which has the portion f
projecting beyond this slot. The head of the screw 9 bears against this portion f
and is screwed into a projection from the frame F the end of the threaded part
being slotted. By screwing this screw further in the head presses the portion f of
the brake-strap outward thereby crowding the shoe harder against the pulley the
fulcrum being in the end of the frame F. By placing the head of the screw
between the portion f of the brake strap and the projection from the frame F, the
adjusting screw is securely retained in place and can not be lost out accidentally.
A slot is provided in the frame A opposite the end of screw g so as to enable an
adjustment of the brake pressure without disturbing the position of the device.
Other modifications in the construction of this device may be employed such as
altering the position of the brake to the upper end of the frame F and allowing the
cable to pass under pulley E instead of over it but I have not illustrated these modifi-
cations as they involve no new features and the constructions shown are preferred.
Having now particularly described and ascertained the nature of the said invention
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 ;-
1. In a sash balance the combination of a face plate A with the spring drum
bolding the cable D and a swinging guide pulley E over which the cable passes sub-
stantially as described.
2. In a sash balance the combination of a face plate A with spring drum C holding
the cable D a swinging guide pulley E over which the cable passes and a brake H
operating on the guide pulley substantially as described.
3. In a sash balance the combination of a face plate A with spring drum C holding
the cable D a swinging guide pulley E over which the cable passes a brake H
operating on the guide pulley E and a guard G to protect the cable substantially as
described.
4. In a sash balance the combination with a face plate A with spring drum C
holding cable D a swinging guide pulley E over which the cable passes and an
adjustable brake H operating on the guide pulley with an adjusting screw g bearing
on the prolongation of the brake strap substantially as described.
5. In a sash balance the combination of a face plate A the spring drum (holding
the cable D and guide pulley E over which the cable passes together with a frame
holding said guide pulley and swinging in a plane at right angles to the face plate sub-
stantially as described.
6. In a sash balance the combination of a spring drum holding the cable a guide
pulley over which the cable passes a brake operating upon said guide pulley and an
adjusting screw for increasing or diminishing the pressure of said brake substantially
as described.
7. In a sash balance the combination of a face plate A a grooved spring drum C
to which the cable D is attached and having said cable run in the grooves of said drum
with a guide pulley E over which said cable passes and a ¡brake operating upon said
guide pulley substantially as described.
Dated this 7th day of Januar 1800
W. P. THOMPSON & BOULT,,
Agents for the Applicant.