Note: Descriptions are shown in the official language in which they were submitted.
9358
FRICTION STAY ~RM ASSEMBLY FOR A WINDOW
.
The present invention relates to a friction
stay arm for a hinged window sash in a window frame. More
specifically the present invention provides a novel
friction locking member for a friction stay arm assembly
suitable for a window which allows a hinged window sash
to be locked in any open window position.
Hinged window assemblies require some type of
stay arm system so that a window sash may be swung open and
locked in at least one open window position, otherwise wind
can force ~he window sash to swing. There are many types of
stay arm systems, some of the older designs have a series of
specific positions with holes in a swing arm which fit over
a pin fixed to the window frame. Another system provides a
rotating handle and mechanism on the frame which moves a lever
connected to the window sash. Perhaps the most desirable type
of window opening system is one which is simple and requires
a person to push a window sash to any desired open window
position and then lock the window sash in that position
knowing that it will not move when it is left.
Friction stay arms are provided which partially
meet this demand. They have a friction member which runs in
a trac~ mounted on the window sash with a pivot link between
the friction member and the frame. However, such a system
requires a falrly heavy push or pull in order to overcome
the friction and open or close the window. This system may
be acceptable for an inward opening window, however, for an
outward opening window, the friction force to overcome wind
and hold the window in an open position has to be so great
that it becomes difficult to open and close the window.
Another type of friction stay arm mechanism for a
hinged window includes one which has a loc~ing handle in the
window sash that can be turned from a locked position to a
..~
- 2 ~ 9~58
sliding position. In the sliding position, the window sash
can be pushed open and clos~d and moves relatively easily
about its hinge, then by turning the handle to the locked
position, 'the window sash is locked and is not supposed to
swing.' Most existing designs of this type, however, rely
on metal to metal sliding friction to stop the swinging and
this is generally not sufficient to prevent the window sash
swinging in a high wind. Furthermore, if one does use metal
to metal friction locking,'then the ~orce required to rotate
the locking handle becomes excessive, preventing children or
older people from uslng the window.
The present invention overcomes the problems of a
friction stay arm mechanism which does not lock properly when
the locking handle is in a locked position, by providing a
sliding member which slides in a track fixed to the window
sash, 'the sliding member having a friction surface which
when pushed into engagement with flanges or rails on the
track, 'locks the sliding member to the track in a positive
manner without undue pressure being applied, such that strong
2~ winds cannot move the position af the window sash.
~he present invention provides in a friction stay
arm assembly for a hinged window sash in a window frame,
including a locking handle in the window sash having a
sliding position and a locked position, extension arm mech-
amism means connected from the handle, channel shaped track
in one side of the window sash having a fixed ramp member
therein, a movable ramp member positioned in the track, and
connected to the extension arm mechanism means such that
when the handle is turned from the sliding position to the
locked position,'the movable ramp member-moves adjacent the
fixed ramp member in the track, 'sliding member in the track,
free to slide when the handle is in the sliding position,
and locked by the movable ramp member and the fixed ramp
member when the handle is in the locked position, arm member
~ ~ 3 - ~59358
having one end pivotally attached to the sliding member and
the other~end pivotally attached to a fixed position on the
window frame, the improvement comprising inward facing
shoulders at extremities of flanges on the channel shaped
track, the sliding member having a friction surface to engage
with the inward facing shoulders of the track when the handle
is in the locked position, the friction surface being forced
against the inward facing shoulders of the track by the
movable ramp member and the fixed ramp member.
In other embodiments of the invention, the sliding
member has a T-shaped cross section with a side flange of the
T-shape touching the inward facing shoulders of the track.
Friction material may be provided for the friction surface
with metal protective pieces at each end of the sliding member
and the friction material preferably stands higher than the
metal protective pieces permitting only the friction material
to engage with the inward facing shoulders of the track.
Preferably the friction material is glued to a metal back-u~ strip
of the sliding member which is formed integrally with the
metal protective pieces. The friction material is preferably
a carbon composition having metal flakes embedded therein.
In drawings which illustrate embodiments of the
invention,
Figure 1 is a front elevational view showing a
double sash hinged window assembly,
Figure 2 is an exploded view showing a friction
stay arm assembly for a hinged sash window assembly,
Figure 3 is a partial sectional front view showing
the top of a window sash with the channel shaped track and
stay arm,
Figure 4 is a side sectional view through the
channel shaped track of a friction stay ar~ assembly,
Figure 5 is a top view showing the friction stay
arm assembly of Figure 4,
4- 1~5~58
Fi.gure 6 is.a top view of a sliding member which
slides in the channel shaped track of the friction stay arm
assembly,
Figure 7 is a side view of the sliding member
shown in Figure 6,
Figure 8 is a sectional view taken at line 8-8
of Figure 7.
Figure l-shows a side hung casement window with
two hinged sashes 10.opening in a window frame ll. A friction
stay arm assembly 15 is shown in Figure 2. One such assembly
15 is fitted in each window sash 10. A locking handle 16 is
positioned on the opening side of each sash 10 at a convenient
height, and is connected by means of a pinion and ratchet
connection 11 to a first extension arm 18 which extends both
upwards and downwards in the window sash 10. Although not
specifically forming part of this invention, the first extension
arm 18 generally has a bolt 20 at its bottom end for insertion
into the frame ll of the window to provide a positive lock
when the sash is closed. In another embodiment, locking
pieces 21 on the side of one sash engage in locking sockets
(not shown) on the adjacent sash to positively lock both
sashes together when they are both closed. The first extension
arm 18 is connected at its top to an angle portion 22 with a
flexible member 23 to carry the movement of the extension arm
18.around to the top of the sash and connects to a second
25- extension arm 24. As can be seen in Figure 3, the second
extension arm 23 joins to a movable ramp member 25 comprising
a number of sloping ramps which is illustrated more clearly
in Figure 4. The movable ramp member 25 reciprocates back-
wardsand forwards in a channel shaped track 26 which includes
a stationary ramp member 27 in the base of the track 26. The
stationary ramp member has a number of sloping ramps approx-
imately the same length and slope as the movable ramp member
25 so that when the movable ramp member 25 is moved to the
right (when looking at Figure 4) the member 25 is forced
_ 5 _ ~L2S9358
upwards away from the fixed ramp member 27 and when moved
to the left, it moves downwards following the slope of the
ramps. On top of the movable ramp member 25 is a sliding
member 28 which has a pivot 29 at its center and is attached
to an arm 30 as shown in Figure 5. At the end of the arm 30
is a -second pivot 3I connecting the arm 30 to an attachment
32 which is flxed in a fixed position to the window frame 11.
In operation of the friction stay arm assembly,
the locking handle 16 is turned from a locked position which
is when the movable ramp mernber 25 is to the right and thus
is raised as far as possible above the fixed ramp member 27.
~his causes the movable ramp mem3~er 25 ~o push the sliding
member 28 up against inward facing shoulders 33 at the top of
the channel shaped track 26 and locks the sliding member 28
so it cannot slide in the track 26. When the handle 16 is
moved to the sliding position, the movable ramp member 25
moves to the left so that it is in a lower elevation, and does
not push against the sliding rnernber 28 leaving it free to
slide in the channel shaped track 26.
The sliding member 28 is better illustrated in
Figures 6, 7 and 8 and comprises a metal backing strip 40
having a T-shaped cross section as shown in Figure 8. Metal
protective pieces 41 are provided on each end of the backing
strip 40 and are formed integral therewith. A central metal .
portion 42 has a stud 43 for the pivot connection 29 to arm
30. A steel spring membex 45 bows down underneath the
sliding member 28 providing some resilience and preventing
the sliding member 28 from rattling in the track 26. Friction
material pieces 47 are placed between the protective peices
41 and the central portion 42 of the sliding member 28. They
are substantially T-shaped, and arranged so that the flange
48 of the T-shaped friction member is raised above the flanges
of the protective pieces 41 and the central portion 42 of the
sliding member 28, thus ensuring that when the sliding member
- 6 - ~2 5 935 8
28 is pushed up to make contact with the inward facing
shoulders 3~ o the track 26, then it is the friction surface
48 which touches the track and not the metal surface. It is
found that the friction surface requires considerable less
pressure to form a positive lock and prevent the window sash
from moving. This means ~hat the force required to rotate
the handle rom the sliding position to the locked position,
is much less than required in a unit which does nat have a
friction surface to st~p the sliding member from movingO
In a preerred embodiment, the friction surface
i~ a carbon material having metal flakes therein similar to
that used in brake pa~s and the like, sold under the trade
mark FERODO brake lining material. It is found that by sub-
stituting the friction surface in place of a metal surface, and
using the same force to turn the handle 16 on the sash, the
locking force for the opening sash in increased by at least
300%. The movable ramp member 25 and fixed ramp member 27 are
preferably~formed of brass, although other suitable metal alloys
ma~ be used provided they do not distort or seize together.
Various changes may be made to the friction stay
arm assembly as illustrated herein without departing from the
scope of the present invention which is limited only by the
follawing claims.
3Q
