Automatic Locking and Adjustable Sash Balance.
Year: 1896

page_text: Date of Application, 17th Mar., 1896-Accepted, 25th Apr., 1896
COMPLETE SPECIFICATION.
Automatic Locking and Adjustable Sash Balance.
I, ROBERT KNOX BROWN, of Prospect Cottage, Whitinsville, Worcester
County, State of Massachusetts, United States of America, Accountant, 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 sash balances, adapted for use in
connection with window sashes, for the purpose of facilitating the raising and
lowering of the window sash, as well as preventing the rattling of the sash, by wind
or otherwise, my improvements being applicable to various kinds of window sashes,
though they are particularly applicable to sash balances to be used on car
windows.
It is well known, that the wood, of which window frames and sashes are usually
made, is often imperfectly seasoned, and in consequence of this the sashes and
frames frequently shrink, so that the sashes become loose and rattle in the frames,
and on cars the sashes are caused to rattle both by the jarring motion of the car as
well as from the action of the wind.
The chief objects of my invention are not only to effectively provide against the
objectionable rattling of the sash and to secure easy control of the window, when
raising or lowering the same, but also to provide a simple, economically constructed,
and effective sash balance in which the parts are compactly and neatly arranged
and in which the balance, when in operative position, is entirely hid from view with
the exception only of a locking and unlocking lever arm.
My invention has also for its object to improve the constructive details of sash
balances of the character referred to as hereinafter described.
I will describe my invention with reference to the accompanying drawings of
which
Figure represents in vertical, sectional elevation part of a window frame,
showing in position the preferred form of my sash balance.
Figure 2 is a vertical section of the sash balance, window frame and window
sash.
Figure 3 is a horizontal section of the same.
Figure 4 is a rear elevation of the sash balance illustrated in Figure 1.
Figure 5 is a sectional detail of a modified form of spring barrel.
Figure 6 shews in elevation, a preferred form of sash engaging device.
Figure 7 is a horizontal, sectional view of another modification of the sash
balance.
Figure 8 shews in front and side views a portion of the sash engaging device
shown in Figure 6 drawn to a larger scale.
Referring to the drawings A indicates the vertical stile of the window sash, and
B, the vertical stile of the window frame, against which are secured the usual
retaining strips V, Figure 3, between which strips the vertical edges of the
window are held and move.
In Figures 1 to 4, there is a casing E enclosing a spring barrel F which latter in
its preferred form is a cup-shaped piece of metal, from the inner side of which

page_text: projects a spinale I, rotatably mounted in a hub T, projecting inwardly from the
enclosing case E.
The closed side of the spring barrel is provided with a circular projection 9,
fitting a corresponding recess in a projecting flange D, on one side of a shell or
casting C, by means of which the said barrel can be readily centered, when the
parts are being placed in position. The other side of the casting C, is provided
with a flange Di extending beyond the hub T, on the casing E, and resting against
the same, as shewn in Figures 3 and 4, the two flanges thus confining between them
the spring barrel, and its enclosing case E. Two flanges c project from the
casting C, on either side of the flange D, for the purpose of enabling the ready
application of the casting to the window frame, as hereinafter more fully described.
This casting C, constitutes the base on which the other parts of the device are
carried, and comprises the side walls from which the flanges D and D' project, end
walls forming continuations of the side walls, and the bottom plate, the latter of
which is perforated or slotted to permit the sash engaging device on the spring
barrel to project therethrough and engage the sash, as clearly seen in Figures 1, 2,
3 and 7.
Extending from the bottom of the casting C in the same plane are two ears or
flanges c. through which suitable fastening devices, such as screws, are passed into
the window frame for securing the balance in place. At right angles to the
bottom plate of the casting C two guide flanges or lips c¹, extend, these lips being
slightly offset from the face of the flange D, thus providing a recess, in which the
locking and interlocking lever arm L can operate. These two lips are provided
for the purpose of enabling the ready application of the device to the window
frame, without necessitating accurate measurements, this being quickly and realily
accomplished by simply setting the device, into the recess in the window frame,
with the lips aligning, and flush, with the side of the box or groove, in which the
sash slides. The casting C, constructed as described, forms a shallow box or shell
in which the casing E, enclosing the spring barrel F is adjustably held by means
of bolts K passing loosely through holes in the bottom plate of the casting C, and
through similar holes in projecting flanges e on the casing E. The outer ends of
the bolts K are screw-threaded and provided with nuts n, between which nuts, and
the flanges e coil springs are interposed the said springs tending to press the
casing E and the barrel F carried thereby through the opening in the bottom of
the casting and toward the window sash;-between the flanges e and the bottom
of the casting C, another set of coil springs el Figure 2 is interposed the said
springs, tending to press the casing E in the opposite direction. By screwing or
unscrewing the nuts n, on the bolts K, the spring barrel may be readily aud
delicately adjusted in position with relation to the sash.
Upon the periphery of the spring barrel F, I provide rounded or spherical
teeth H adapted to mesh with corresponding rack teeth R on the window sash;
and on one edge of the said barrel, I also preferably provide a series of teeth
with which teeth a locking spring detent S engages to hold the spring barrel
against rotation. This spring detent S is preferably a leaf spring, one end of
which is arranged to rest against the inner wall of the casing E, the other end
being slightly bent so as to form a tooth to engage the teeth on the barrel; this
spring is confined, between the ends thereof, by a bar G, formed between two holes
made in the periphery of the casing E, the body portion of the spring passing
through these holes and over the outside of the bar. Within the barrel F is a coil
spring 1, the outer end of which is confined in a recess or groove in the inner
periphery of the barrel, the other end being confined in a similar groove in the
fixed hub T so that as the window sash is lowered, the rack R engaging with the
teeth H, on the barrel, the said barrel rotates and winds up the said spring thus
storing up energy sufficient to operate the balance in raising the window.
In order to operate the detent S to release the spring barrel, when it is desired
to raise or lower the sash, the lever arm L, which is pivotted to one side of the
axis of the barrel, at on the flange D, has one end beat as shewn in Figures 3

page_text: and 7 so as to engage with the underside of the spring detent S so that by
depressing the projecting end of the lever arm L the said detent will be raised out
of engagement with the teeth & on the barrel F, and permit of the sash being
easily raised or lowered, the energy stored up in the spring facilitating the raising
and causing it to respond to the slightest pressure in raising the window. When
the arm L is released the spring detent S instantly forces its end down and drops
into engagement with the teeth h, again locking the spring barrel.
It will be observed that this lever arm L works between the two flanges c¹, in
the casting C, the said flanges being raised above the surface of the flange Da
distance equal to the thickness of the lever arm L, thus forming a recess in the
window frame. The arm I is normally out of operative engagement with the
spring detent S, so that the said detent always locks the window against raising or
lowering until the arm is operated to lift it out of contact with the teeth A, on the
spring barrel, the outer or projecting arm of the unlocking lever being provided
with a suitable cord or chain, if desired, or other convenient means may be attached
thereto, for the purpose of operating it.
One or more of my sash balances may be used as desired, according to the size
and weight of the window, and they may be placed on opposite sides of the window
frame, the parts all being reversible and interchangeable so that the balance may
be placed on the right or left hand side of the window. When only one balance is
used, it is desirable to provide a friction roller, such as W, within a recess at the
lower part of the sash, which roller overcomes any friction of the sash on the frame.
These rollers may be applied to both sides of the frame if desired.
When the sash balance is applied for operating the upper sash of a window, the
balance, with the parts arranged as shown in the drawings, is set into the window
frame opposite the lower rail of the upper sash, the lower bolt K being just below
the said lower rail, so that a screw driver may be inserted into the slot in the bolt
head, to effect the adjustment of the spring barrel, with relation to the rack on the
window sash, the upper adjusting bult being adjusted, in the same manner, after the
sash is lowered.
When the balance is applied for operating the lower sash, it is set in the window
frame nearly opposite the upper rail of the lower sash with the upper adjusting
screw bolt above the said rail, thus allowing the screw driver to enter the slot in
the head thereof for the purpose of adjusting the spring barrel in the manner
before stated. The sash is then raised and the other screw bolt adjusted in the
same manner.
For operating a car window sash the balance is set into the frame near the upper
rail of the sash to allow the window to be raised sufficiently high. After the sash
is fitted to the frame and provided with a groove to permit the insertion of the
metal strip forming the rack in the sash without binding on the frame, the strip is
secured to the side sash so that the centres of the teeth in the strip will centre with
the teeth on the spring barrel.
In Figure 5, I have shown a modified form of spring barrel, the said barrel being
composed of two parts, namely, a ring F, which is provided with the operating
teeth H in its outer periphery, and a cup-shaped disc F, provided on its outer
periphery with the teeth, for the detent S to engage. The disc F" forms
the bottom of the barrel and from which projects the spindle P, the outer side
of the disc being provided with the circular projection g, as in the construction
hereinbefore described.
The two parts F and F', are secured together by suitable screws, a rubber or
other flexible washer r, being confined between the meeting edges.
In Figure 6 I bave shown a common square toothed rack and pinion R¹ and H",
which is preferable to the spherical tooth rack and pinion before described. In this
modification the anti friction roll W, is seated and revolves between two of the teeth
in the rack R, this being a neat and cheap anti-friction device, for overcoming any
friction of the sash on the frame. Furthermore, the staple fastener v', which
secures the rack to the sash, acts as a stop for the rotating barrel.

page_text: Z Fig. 8 is a metal plate secured to the lower end of the rack, for the ends of the
friction roll W to run on.
When one balance only is used in a sash there will, of course, be only one
rack and pinion, and in such case, the anti friction roll W is placed on the
opposite side of the sash, or preferably by means of a casting corresponding to
the lower end of the rack, the said casting being held in place by a staple v', as
shown in Figure 6.
In Figure 7 I have shown the engaging device between the spring barrel and
sash as composed of a flexible tyre H, of rubber, or the like, which tyre meshes
with a groove in the window sash. In this construction the spring barrel is
preferably made of two parts, and y, of which the part y carries the teeth h, and
spindle I, while the part a carries the hub T and is arranged to clamp the tyre H¹¹
between a peripheral flange thereon and a flange on the part y. These two parts
are held together by screws k, a space between the parts & and y, permitting of a
limited adjustment of the parts with respect to each other by means of the
screws k.
This elastic tyre will adjust itself to a limited extent of shrinkage of the window
sash, and can be further adjusted with reference to the sash by increasing or
diminishing the side pressure on the tyre through the medium of the screws k, a
compression of the tyre laterally effecting a radial expansion of the said tyre, to
take up shrinkage, and a diminution of such pressure effecting a radial contraction,
to compensate for swelling.
While I have shown the spring detent S as normally disengaged from the arm L,
for locking and unlocking the device, I do not wish to confine myself, to this specific
form of mechanism, as I may adapt any suitable locking device to the various forms
of balances shown.
To wind up the spring barrel to the proper tension for balancing the sash, the
sash is put into the frame when the sash is in its open position, then when the sash
is closed, the engaging device on the barrel meshing with the rack on the sash
causes the barrel to turn so as to wind up the spring I. Should one such
operation be insufficient to secure the proper tension, it may be repeated as
often as necessary, by taking the sash out and reinserting it at the open position
each time.
It will be noted that the balance, after it is once adjusted and in position, is
always locked, except when the pressure is applied to the lever arm so as to lift the
detent out of engagement with the barrel, the barrel being again automatically
locked, when the pressure is removed from the arm.
The lever for operating the lower sash of ordinary windows or a railway car
sash is always arranged to be within easy reach of the hand, and the detent and
lever may be reversed and interchanged for either a downward or upward movement
of the arm, as the case may require. In the case of the upper sash the lever on the
upper balance can be operated by a cord or chain led upward by suitable means on
the frame, and down to within easy reach of the hand, the movement of the lever
being upward. In all windows the "parting box strip" in the frame, between the
two sashes, make a space between the upper rail of the lower sash, and the lower
rail of the upper sash; the rails of the upper sash do not touch the upper lever
arm, and as the extreme width line of lower "meeting rail" is the centre line of
the "parting box strip" there is a space between the lower "meeting rail" and
the upper sash sufficient for the upper balance lever arm to operate in without
being touched or interfered with by the lower sash rails, and the free movement of
the cord or chain and lever arm to operate the upper sash balance. Another
important feature is that, where more than one balance on one sash is required, (for
instance, one on each side of the sash) only one locking device is required to be
operated, the detent and lever arranged on the other side being inoperative
excepting when the sash is out of the frame for rewinding, for when one side
is locked the other side is held effectually as if both locking devices were in
operation.

page_text: 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 :-
1st. The herein described sash balance for windows, consisting of a casting or
shell adapted to be secured in a recess in the window frame, a barrel rotatably
mounted in the said casting, and provided with meaus on its periphery for engaging
the side of the window sash, a spring detent normally locking the barrel against
rotation, and a lever arm pivotted to one side of the axis of the barrel normally out
of engagement with the said detent and arranged to lift the detent out of
engagement with the barrel, substantially as hereinbefore described.
2nd. The herein described sash balance for windows, consisting of a shell or
casting provided with guide lips on each end in alignment with the box strip of
the window frame, a spring barrel rotatably mounted in the casting and having an
engaging device on its periphery for engaging the side of a window sash, with
mechanism for locking and unlocking the sash balance, substantially as hereinbefore
described.
3rd. The herein described sash balance, consisting of a shell or casting adapted
to be secured within a recess in a window frame, a spring operated barrel, rotatably
mounted in the said casting, the said barrel haring on its periphery an engaging
device for engaging with the side of a window sash, and a set of locking teeth, a
detent normally in engagement with the said teeth, and a lever normally out of
operative engagement with the detent for lifting and holding the said detent out of
contact with the said teeth to allow the barrel to rotate, substantially as hereinbefore
described.
4th. In a sash balance, the combination with the window frame provided with a
recess, of a casting or shell having flanges projecting within the recess, a spring
operated barrel rotatably and adjustably mounted between the flanges, and having
in its periphery a device for engaging the side of the window sash, and a set of
teeth for locking the barrel, a spring detent normally in contact with the teeth to
lock the said barrel, and a lever arm pivotted to one side of the axis of the barrel,
upon one of the flanges of the casting and adapted to raise the detent and unlock
the barrel, substantially as herein before described.
5th. In a sash balance, the combination with the window frame having a recess
therein, of a casting or shell provided with flanges secured to the frame, and a pair
of parallel flanges projecting at right angles thereto, within the recess of the frame,
a spring operated barrel mounted in the casting between the said flanges, guide
lips extending from the casting so as to be quickly aligned with the box strip of
the window frame, the inner portions of the said lips being slightly raised above
the shell side and barrel supporting flange forming a recess, a lever pivotted
upon the barrel supporting flange and having one end extending through the rear
between the lips and the other end into the recess of the frame, a detent normally
locking the barrel against rotation, with which detent the said lever arm is
adapted to engage and lift it out of contact with the barrel, substantially as
bereinbefore described.
6th. In a sash balance, the combination with the shell or casting having parallel
barrel supporting flanges therein, one of the said flanges being provided with a
centering recess on its inner side, a casing closed on one side and provided with a
centrally projecting hub and adjustably mounted in the casting, a cup-shaped
barrel having a spindle fitting in the said hub, and provided on its closed side with
a circular projection meshing with the recess on the supporting flange, substantially
as hereinbefore described.
7th. In a sash balance, the combination with the shell or casting C provided
with parallel flanges extending from the base thereof, an operating barrel supported
between the said Hanges, and projecting through the base of the shell to engage
the side of the window sash, a cup-shaped shell enclosing the barrel, a spring
Sent having its body portion engaged by a bar formed in the periphery of the

page_text: shell E and its free end normally holding the barrel against rotation, a lever
pivotted on one of the flanges, one end of the said lever being normally out of
operative engagement with the detent and adapted to be brought into contact
therewith to disengage the detent from the barrel, substantially as herein before
described.
Dated this 17th day of March 1896.
JOHNSONS & WILLCOX,
47 Lincoln's Inn Fields, London, W.C., Agents.