Movable or removable closures – With means mounting closure for reciprocation – With counterbalance
Reexamination Certificate
2002-02-22
2004-03-02
Redman, Jerry (Department: 3634)
Movable or removable closures
With means mounting closure for reciprocation
With counterbalance
Reexamination Certificate
active
06698139
ABSTRACT:
This invention relates to a sliding sash type window assembly which comprises a fixed rectangular outer frame securable in a window aperture in a building, upper and lower window units mounted in the fixed outer frame with at least one of said units being movable between an open position and a closed position of the window assembly, and respective rectangular frames for said units arranged to permit a lower horizontal frame member of the upper unit to be located alongside an upper horizontal frame member of the lower unit when the window assembly is closed so that a locking element can lock the frame members to each other and thereby prevent unauthorised attempt at forced opening of the window assembly.
Sliding sash type windows have been supplied with timber frames for many years, in which both the upper and the lower window units are capable of vertical sliding movement (one in front of the other) within guide tracks provided in the outer frame, and usually the upper unit is stepped outwardly of the lower unit i.e. it moves in an outer vertical plane which is spaced from an inner plane in which the lower unit is movable. The lower horizontal frame member of the upper unit is located alongside the upper horizontal frame member of the lower unit when both units are in their closed positions, and a suitable lock e.g. a Fitch lock secures the frame members together to prevent forced opening of the window assembly.
Timber frame window units, and the glazing of the units, are heavy, and therefore to facilitate opening and closing movement of the units, it has been traditional to provide counterweight arrangements comprising lead weights, cords and pulleys. The lead weights move up and down within concealed vertical passages defined behind front facings of the vertical side frame members of the fixed frame, but the cords which transmit tensile loads between the lead weights and the window units necessarily are exposed to view, since they must run down the exposed facings to make connections with anchor points on the side frames of the window units.
It is also known to provide adjustable spring assemblies, to provide counterbalance forces to the weights of the sliding sash window units. However, these are quite complicated, expensive, and can require maintenance over a period of time, which is a serious drawback to potential users.
In order to provide for ease of upward and downward movement of sash window units (bearing in mind that the timber components may change in size with temperature changes, or swelling with moisture ingress), it is usual to provide substantial clearances to the movement of the units within the guide provided in the vertical frame members of the fixed frame. This means that in practice when the units are closed, there are often substantial air gaps between the sash window units and the fixed outer frame, which allow drafts of external air to pass through the gaps and into a room. Also, in windy conditions, the sash units can clatter against each other.
Both of these factors are an inevitable feature of traditional timber designs of sash windows, whether genuinely old installations e.g. for Victorian or earlier eras, or from more modern installations in timber.
However, despite these drawbacks, there is substantial design appeal to customers of traditional designs of timber sliding sash windows, and there is a clear commercial demand for the design appeal of these traditional designs to be made available, but preferably utilising more modern materials and sealing techniques, and particularly extruded PVCU sections fibreglass mouldings or aluminium. However, for some users, the invention may be applied to timber framed windows.
To satisfy this need, initial attempts have concentrated on providing a visual illusion i.e. a simulation of vertically sliding sash window units, and using PVCU material to form the fixed outer frame and also the frames of the sash units mounted therein. To form the illusion, it is necessary to mount the sash units in respective off-set vertical planes, so as to make it appear as if the units could be slid vertically one in front of the other.
However, in practice, the lower unit is usually fixedly mounted in the outer frame, and the upper unit is a “top open” window which can move hingedly outwardly about an upper horizontal hinge axis.
By this illusion, while using modern materials, the appearance of sliding sash window units can be obtained, but without need to provide (a) counterweight arrangements and (b) vertical guide tracks in the side frame members of the fixed frame.
SUMMARY OF THE INVENTION
The present invention approaches the task of simulating traditional timber frame sliding sash designs, using modern materials, and in a way which actually replicates the vertical sliding movement of traditional timber designs, but also utilising counterweight arrangements which are technically and/or visually improved over existing arrangements.
According to one aspect of the invention there is provided a sliding sash window assembly which comprises a fixed rectangular outer frame securable in a window aperture in a building, upper and lower window units mounted in the fixed outer frame and at of said units being relatively movable between an open position and a closed position of the window assembly, respective rectangular frames for said units arranged to permit a lower horizontal frame member of the upper unit to be located alongside an upper horizontal frame member of the lower unit when the window assembly is closed and a locking element for locking the frame members to each other in a closed position and thereby preventing unauthorized attempts at forced opening of the window assembly, in which:
(a) the rectangular outer frame has side frame members in which counterweight arrangements are housed and which are operable to control the upward and downward sliding movement of said one movable window unit in said outer frame, the side frame members having facing to conceal the counterweight arrangements from view;
(b) each counterweight arrangement includes an elongate tensile element which is connected at one end to a lower end region of said one movable window unit and which is connected at its opposite end to a load which is housed behind the respective facing whereby one portion of the elongate tensile element is also located behind the facing, and another portion of the elongate tensile element extends upwardly of said lower end region of said one movable window unit and alongside a side frame thereof during raising and lowering movement of said one movable window unit; and,
(c) each elongate tensile element is routed through an aperture in a respective one of the facings which is located generally at the level of the lower horizontal frame member of the upper unit and the upper horizontal frame member of the lower unit in the closed position of the window assembly so that, when in this position, the aperture is concealed from view and the tensile element also is not visible.
According to a second aspect of the invention there is provided a sliding sash window assembly which comprises a fixed rectangular outer frame securable in a window aperture in a building, upper and lower window units mounted in the fixed outer frame and one of said units being relatively movable between an open position and a closed position of the window assembly, and respective rectangular frames for said units arranged to permit a lower horizontal frame member of the upper unit to be located alongside an upper horizontal frame member of the lower unit when the window assembly is closed so that a locking element can lock the frame members to each other and thereby prevent unauthorized attempts at forced opening of the window assembly, in which:
(a) the rectangular outer frame has side frames in which counterweight arrangements are housed and which are operable to control the upward and downward sliding movement of said one movable window unit in said outer frame, the side frames having facings to conceal the counterweight arrangements from view;
(b) each co
Leydig , Voit & Mayer, Ltd.
Redman Jerry
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