US3345776A

US3345776A - Vertical opening sash

Info

Publication number: US3345776A
Application number: US503931A
Authority: US
Inventors: Laurence F Carson
Original assignee: Pittsburgh Plate Glass Co
Current assignee: PPG Industries Inc
Priority date: 1965-04-28
Filing date: 1965-10-23
Publication date: 1967-10-10
Anticipated expiration: 1984-10-10

Description

Oct. 10, 1967 L. F. CARSON VERTICAL OPENING SASH Filed Oct. 23, 1965 FIG.3

FlG.2

6 Sheets-Sheet 1 L. F. CARSON VERTICAL OPENING SASH Oct. 10, 1967 6 Sheets-Sheet 2 Filed Oct. 23, 1965 2 n m 5 I bl Ar \2 0 MMU N, u m H H u o w 4 KY2 s 5w 3 8 I 5 mm 2% Q x Q/ Y /i I M E w J 6 A 2 w w Oct. 10, 1967 L. F. CARSON 3,345,776

VERTICAL OPENING SASH Oct. 10, 1967 L- F. CARSON 3,345,776

VERTICAL OPENING SASH Filed Oct. 23, 1965 6 Sheets-Sheet 4 FIG. 6

Oct. 10, 1967 Filed Oct. 23, 1965 L. F. CARSON VERTICAL OPENING sAsH 6 Sheets-Sheet 5 0d. 10, 1967 L. F. CARSON 3,345,776

VERTICAL OPENING SASH Filed 001;. 23, 1965 6 Sheets-Sheet 6 United States Patent O 17 Claims. Cl- 49246) ABSTRACT OF THE DISCLOSURE This relates to windows in general and in particular, to a mounting assembly for a window unit whereby such unit may be moved in a direction normal to the plane f the glazing; to a window frame of particular construction; to the particular construction of a window unit and to a seal between a window frame and a window unit.

Windows in the walls of buildings are mounted to lie normally in a vertical plane in a closed position and accordingly the movement of a window mounted in cordance with the present invention, from a window closed to a window open position and vice versa would be in a substantially horizontal direction with the glass remaining in a substantially vertical plane.

For convenience of description the term window frame used herein refers to the portion fixed to the wall in surrounding relation with respect to a window opening therein and the term window unit refers to the movable portion insertable into the window opening and includes a sub-frame and a glazing portion.

Cleaning the exterior surface of the glazing is often a problem in extremely high office buildings and this is greatly facilitated when the outer surface of the glazing can be reached and cleaned from the interior of the building. Double glazing, however, as is normally used results in rather heavy window units. Also in modern buildings large quantities of glass are used and the size in most cases renders them extremely diflicult to handle. It accordingly has been a problem due to Weight and economics from quantities involved to mount windows to be movable and as a result most buildings use fixed window units.

It is obvious from the size of window units involved that when movably mounted they must be counterbalanced. Lack of a suitable assembly for this purpose has also probably accounted for installating fixed window units. Another factor contributing to the present construction practice includes the lack of a suitable seal between the window frame and the movable Window unit.

It is an object of the present invention to provide a combined counterbalance and mounting assembly for a window unit.

A still further object of the present invention is to P vide a combined window mounting and counterbalance assembly concealed during a window closed position.

A still further object of the present invention is to provide a mounting for a window unit whereby the glazing remains in a substantially vertical position in a Window open and a window closed position.

A still further object of the present invention is to provide means for mounting a window whereby the window unti is entirely removed from the window frame in an open position and thereby provides access to the exterior surface of the glazing around the entire periphery of the window unit.

A still further object is to provide a window unit of particular construction and a window frame each of particular construction.

7 A still object is to provide a window unit and window frame and a pair of seals interposed therebetween around the periphery thereof adjacent respectively the interior and exterior surface of the window glazing.

In accordance with one aspect of the present invention, there is provided a mounting assembly for a window unit movably to mount the latter upon a suitable structure wherein such window unit remains in a substantially vertical plane during movement from a window closed to a window open position. This permits the access to the exterior glazing surface, i.e. the side of the window unit adjacent the window frame in a window open position from the opposite side around substantially the entire periphery of the window unit.

In a further aspect of the present invention there is provided a mounting assembly securable to a window unit and a window frame respectively at spaced positions adjacent the marginal edge of the window unit and disposed in such a position as to be concealed in a window closed position.

In a still further aspect of the present invention there is provided a window seal consisting of an interfitting channel and groove on respective parts of the frame and window unit with a gasket therebetween, such groove and channel being continuous adjacent the outer periphery of the window unit.

In a still further aspect of the present invention there is provided a window unit and a window frame having a pair of seals interposed therebetween about the periphery thereof adjacent respectively the inner and outer surfaces of the glazing.

The invention is illustrated by Way of example in the accompanying drawings wherein:

FIG. 1 is a vertical front elevational view of a window unit mounted on a frame in accordance with the present invention;

FIG. 2 is a side elevational view of the window and frame illustrtaed in FIG. 1 but wherein the window is horizontally moved to the right of the frame;

FIG. 3 is a vertical elevational view of a portion of the means for securing the window to the frame and illustrating with means of adjusting tension to provide various counter-balances for the window;

FIG. 4 is a detailed vertical cross-sectional view along section 4-4 of FIG. 1 showing a window and frame constructed in accordance with the present invention mounted in a window opening of a wall and wherein such window is in a closed position;

FIG. 5 is similar to FIG. 4 but in somewhat less detail illustrating, in phantom, the window in an open position;

FIG. 6 is a cross-sectional view taken along section .66 of FIG. 1;

FIG. 7 is an oblique view illustrating a modified means of mounting a Window unit to a frame in accordance with the present invention;

FIG. 8 is an oblique view of a further modified means of mounting a window unit to a frame in accordance with the present invention; and

FIG. 9 is an oblique view of a still further modified means of mounting a window unit to a frame in accordance with the present invention;

FIG. 10 is a cross-section along section 10-10 of FIG. 3; and FIG. 11 is a partial vertical sectional view illustrating a modified seal between the window unit and the frame.

The drawings illustrate a window assembly which includes a window frame, a window unit and a mounting assembly for securing the window unit to the frame in such a manner as to permit relative movement with respect thereto. The window illustrated is a complete window, however it will be apparent hereinafter that various features are also applicable to ventilating type windows used in conjunction with window units having a fixed portion.

Referring now in detail to the drawings, shown therein is a window assembly consisting of a window unit 10 pivotally secured to a frame 11 by a pair of

mounting assemblies

12 and 13. The window unit 10 includes a double glazed portion 14A of the insulating type and a subframe 14B. The glazing may be of the type identified by the trademark Twindow, wherein two sheets of .glass are held in spaced relation by a suitable peripheral frame. The frame 11, as will be seen hereinafter, is preferably multipart consisting of members of extruded aluminum and the mounting assemblies, which also provide counterbalances consists of a pair of arms interconnected by a torsion bar.

The window unit 10 consists of the previously mentioned glazing portion 14A and a sub-frame 148, the latter being assembled from extruded aluminum sections. The sub-frame (see FIG. 4) includes members 16 and 17 detachably secured together and cooperating clampingly to engage the peripheral edge of the glazing portion.

The member 16 extends around the periphery of the glazing portion and is channel shaped in cross-section having a pair of spaced

flanges

18 and 19 projecting outwardly from the marginal edges of a web 20. Associated with the web, on the side opposite to that of the flanges is a glazing retainer 21 consisting of member 22 secured to the web 20 by a plurality of screws 23 and a cover 24. The cover 24 and member 22 are each L-shaped in cross-section and are standard members for this purpose. One leg of the member 22 has a sealing material 22A adhering thereto which bears a surface of the glazing portion adjacent the peripheral edge thereof.

The member 17 includes spaced

flanges

25 and 26 projecting from a web 27 to define a channel 28 and a flange 29 projecting from the flange 26 in a direction parallel to the web 27 but in spaced relation with respect thereto. The web 27 of member 17 and the flange 18 of member 16 may be detachably secured together face-to-face as by bolts, screws or the like and if desired, a neoprene or the like gasket may be interposed therebetween to provide a thermal barrier. The flange 29 and glazing retainer 21 are spaced apart to define a groove 30 therebetween to receive the marginal edge of the glazing. A sealing compound 29A is interposed between the flange 29 and the adjacent surface of the glazing portion 14A. It is obvious from the foregoing that the groove 30 may be varied in width to accommodate various thickness of glazing by either variously positioning the glazing retainer 21 with respect to the web 20 or alternatively positioning selected spacers between the abutting flange and web of members 16 and 17. From FIG. 4 it will be noted that the flange 19 of member 16 projects out wardly laterally beyond the member 17 and the purpose of this will become more apparent hereinafter.

The window frame 11 (see FIGS. 4 and consists of a pair of solid extruded aluminum members 40 and '50 detachably secured together. The member 40 consists of a first flange 41 and a second flange 42 disposed substantially at right angles to one another with a further flange portion 43 directed normal to the latter intermediate its ends. The flange 42 terminates at the marginal edge in a groove 44 and as will be seen here inafter cooperates with a flange, on member detachably to' retain such members in a selected position.

The member 50 includes a first flange 51 parallel to and in spaced relation with respect to flange 41 and a further flange 52 normal thereto and directed towards the flange 42 of member 40. The flange 52 terminates in an outwardly directed flange 53 adapted to fit into the groove 44 of member 40 and thereby retain such members in a selected position. The member 50 includes a flange 54 disposed intermediate the marginal edges of flange 52 and projecting therefrom is an inwardly turned flange 55 which effectively forms a ledge circumscribing a window opening defined by the frame. The flange 55 is of such dimension as to fit into the channel 28 of the window frame 15 with space therebetween to receive a gasket The

members

40 and 50 are secured to and form a covering for three faces of a member 60 which may be wood or the like. The

members

40 and 50 are secured together and to the member 60 by a plurality of screws 61 which pass through apertures in the

flanges

42 and 52. The member 60 fits into a window opening in a wall 71 of concrete or the like and wedges 72 may be interposed therebetween to provide a suitable fit. The

flanges

41 and 51 of respective members 40- and 50 are spaced from the edge of the window opening and this space may be filled with a caulking compound 80. If desired, a neoprene strip may be interposed between the

members

40 and 50 in the groove 44 thermally to isolate such members.

Referring now to FIGURES 2, 3 and 4, each of the mounting

assemblies

12 and 13 are U-shaped and include a pair of arms and 81 extending outwardly from opposed ends of a torsion bar 82. The

arms

80 and 81 may be integrally formed with the torsion bar 82; however, in the preferred form, they are detachably securable thereto. Each of the arms preferably is a bar member as illustrated in FIG. 10 and includes an embossment B at the lower extremity. The embossment has a non-circular in cross-section aperture extending therethrough adapted to receive a correspondingly shaped portion of the torsion bar. It is obvious that other types of securement may be used. The torsion bar 82 of the lower mounting assembly 13 is secured to flange 42 of frame 11 by a pair of restraining

block assemblies

83 and 84 while such bar in the upper mounting assembly 12 is secured to the Web 20 of the window sub-frame 15. The torsion bar is preferably square or otherwise non-circular in cross-section and apertures in the

blocks

83 and 84 through which the torsion bar passes are similarly shaped so that, when the blocks are secured as by mounting bolts 90 or other suitable means, they restrain or prevent rotation of a selected portion of the torsion bar. The

blocks

83 and 84 are movable axially along the torsion bar whereby the effective length of the latter is readily varied and thereby provides means to vary or adjust the tension of the counterweight for the window. The torsion bar is further mounted to each of the respective members by a pair of bearings 85 disposed in spaced relation with respect to

blocks

83 and 84. The bearings 85, as noted in FIGS. 3 and 4, are disposed adjacent respective ones of the opposed ends of the torsion bar and each permit free rotational or twisting movement of the torsion bar. Each of the bearings 85 consists of a sleeve 86 journalled in a body 87 which in turn is secured to the window frame or unit by bolts 90. In a modified form the sleeve 86 may be interposed between the plate 89 and body 87, fitting into suitable recesses in respective ones thereof. Tightening or loosening the bolts 88 in such a modified structure would vary the frictional resistance restraining rotation of the sleeve 86. This accordingly may be utilized as a dampening effect to retain the window in various positions within a limited range. In operation the frictional resistance could be adjusted by the bolts 88 to overcome the torsion spring force within certain limited movement of the window unit. Such an installation would be desirable where the movable window unit is used for ventilating purposes.

The outer extremities of the

legs

80 and 81 of the mounting assembly 13 are pivotally secured to the window frame as. at.91 while the upper mounting assembly 12 has the arms pivotally secured as at 92 to the window frame 11. Each of the

legs

80 and 81 has an aperture (not shown) extending therethrough adjacent the free end thereof. The axis of each aperture is parallel to the longitudinal axis of the torsion bar and receives a pivot pin. A pair of pins P are secured to the web 20 of the window sub-frame member 16. These pins are located on opposite sides of the window unit at a position intermediate the

flanges

18 and 19.

Pins P pivotally mount the free end of the

arms

80 and 81 of mounting assembly 13 to the window unit. Similar pins P are secured to the window frame and project through apertures adjacent the free end of

arms

80 and 81 of the mounting assembly 12.

Alternatively pins may be secured to the arms and project outwardly therefrom to fit into apertures in the respective ones of window frame 11 and window subframe 14.

The flanges 43 and 54 of the window frame abut respectively flange 19 and fit i-ntogroove 28 of the subframe of the window unit and together in a window closed position form a closed channel C extending about the periphery of the window. Assembly 13 and the upper assembly 12 are disposed within the channel C. In the closed position, the torsion bar 82 of the mounting

assemblies

13 and 12 are disposed respectively along the lower and the upper edges of the window unit while the arms. are disposed along the vertical edges thereof.

In FIG. 5, the window assembly is shown (in phantom) in an open position and in such open position it is to the right of the window frame. From this figure, it will be noted that the window, in this position remains vertical i.e., the glazing is in a plane parallel to that of the closed position. This is desirable in that it prevents direct drafts interiorly of the building since the openings effectively are above and below and to each side of the window. In the open position the window unit forms a deflector. The window furthermore when opened moves substantially horizontally and this permits a seal as previously described to be formed between the window assembly and frame circumferentially around the entire window. This horizontal movement allows effecting a tight seal without damage to such seal during opening and closing of the window as occurs with normal windows mounted to pivot through an arc.

The seal 60, as illustrated in FIGURE 4, is U-shaped in cross-section and consists of a web 61 having a spaced pair of parallel legs 62 projecting therefrom. Each leg 62 has a plurality of inwardly directed ribs 63 engaging respective ones of opposed faces of the flange 55. Since the window unit moves horizontally during opening and closing, the flange 65 can project a substantial distance into the groove Without damaging the seal. Furthermore the seal consisting of the interfitting groove and flange can extend entirely around the periphery of the window unit due to the latters horizontal movement during opening and closing.

The flange 19, in a window closed position, bears against the flange 43 and, if desired, a thermal barrier may be interposed therebetween. Such thermal barrier, together with the seal 60 would be effective in thermally isolating the window frame and the window subframe.

A modified form of seal arrangement between the frame and window unit is illustrated in FIG. 11. In the modified form, the window unit sub-frame member 16 has the flange 19 modified at its outer extremity by including an inwardly turned portion 19A. Also, in the modified arrangement, the flange 43- of the window frame member 40 is modified by including at its marginal edge an outwardly directed flange 43A. Effectively the flange 43A and flange 42 of the frame modified member define a groove for receiving a sealing strip 60. The sealing strip is, as previously described, and in the modified form, receives the flange 19A of the window frame sub-assembly. In the modified form, the seal at the opposite side; that is, between the flange 54 of the frame and the groove in the sub-frame may be dispensed with. With the seal formed adjacent the glazing surface interiorly of the building condensation within 6 r the channel C may be drained through an aperture E extending through the flange 54 adjacent the lower edge of the window unit. It has been found that the space between the window unit and the frame effectively forms 'a vacuum and as such has a tendency to draw moisture inwardly. One or more apertures B may be provided and 7 these have a tendency to equalize the atmospheric pressure with that in the channel C or enclosed chamber containing the mounting assembly.

FIG. 6 illustrates -a catch arrangement for retaining the window in a closed position. Shown therein is a bar 110, having a catch 111, mounted on the flange 18 of the member 15 by a spring 112. The bar, by virtue of the spring, is resiliently biased outwardly such that the catch 111 abuts the inner face of the flange 43 of the window frame. The bar 110 has ahandle portion 113 which extends through the flange 19 and may be conveniently shaped readily to be grasped by the fingers.

It is obvious from FIG. 6 that the window may be unlatched by pivoting the handle counterclockwise. A similar arrangement may, of course, be utilized on the opposed vertical side of the window unit and/or the upper and lower edges.

In the embodiments illustrated in FIGS. 1 to 6, the torsion bar is a substantially solid bar; however, it is conceivable that a spiral spring, a flat bar or elongated coil type arrangement could be effective to accomplish the same result. A spiral spring for example may be enclosed in a tube the latter providing means for rigidly securing the mounting assembly to the Window unit or window frame, whichever the case may be. The only requisite is that the torsion bar not only provide means of biasing the window to a closed position but also provide a mounting rigidly to retain the window unit in a selected plane. The only movement permitted in the connection between the torsion bar and the window or frame is oscillatory motion about the longitudinal axis of the torsion bar.

As further alternatives, the window unit may be pivotally secured to the frame in a variety of Ways.

Referring to FIG. 8, the window unit 10 is pivotally secured to the frame 11 by a pair of mounting assemblies 200. Each of the mounting assemblies consists of a substantially L-shaped member having a torsion bar 201 and an arm 202 secured thereto adjacent one end thereof. The arm 202 of one mounting assembly is pivotally secured to the frame 11 while the torsion bar 201 is secured to the upper edge of the window

unit mounting blocks

83 and 85. In the lower mounting assembly 200, the torsion bar 201 is secured to the frame by mounting

blocks

83 and 85 while the arm 202 is pivotally secured at its free end to the window unit.

In this type of installation it is obvious that acertain amount of twisting force will be imposed upon the window unit; however, this could be readily compensated for in the design of the window sub-frame.

A further alternative mounting is illustrated in FIG. 7 wherein only a single mounting assembly 13 is used. In this embodiment the torsion bar portion 82 is mounted on the window frame 11 by two mounting blocks 83 and two mounting blocks 85 while the free ends of the arms and 81 are pivotally secured to marginal vertical edges of the window unit 10. Pivotal attachment, as will be obvious, is disposed at a position vertically above the center of gravity of the window. By such arrangement, the window unit remains suspended freely in a vertical position in an open position. The torsion bar may be mounted in a manner as described with reference to FIG. 4 and the effective length of the torsion bar may be varied to compensate for various weights of windows.

In FIG. 9 there is illustrated a still further modified means of mounting the window unit to the frame. In this embodiment the window unit 10 is secured to the frame 11 by a mounting assembly 300. The mounting assembly 300 consists of a pair of torsion arms 301 and 302 extending from and interconnected by a bar 303. The torsion bars 301 and 302 may be secured respectively to the upper and the lower edge of the window unit 10 and frame 11. It is obvious that the torsion arm 301 need not necessarily provide a biasing force but alternatively could be pivotally secured to the window unit. In the latter case, the window unit would be freely suspended in an open position as is the case in the FIG. 7 embodiment. it is obvious that the torsion arms 301 and 302 may be mounted in a manner similar to that described in FIG. 4 and thus, an adjustment for the effective strength of the torsion bars may be made by moving the restraining block; i.e., moving the restraining block selectively along the length of the torsion arm.

As previously briefly mentioned, the window unit shown in the drawings is a complete or unitary window. The mounting assemblies however and/or the seal arrangement also may be used in secondary or ventilating windows. One particular application is in hopper windows where a relatively small Window unit is disposed adjacent the upper or lower edge of a fixed window unit, the relatively small window unit being for ventilating purposes.

I claim:

1. A window assembly comprising a window frame having a spaced lower and upper pair of members interconnected by a pair of spaced side members to define a window opening, a window unit and means for mounting said window unit to said frame selectively to open and close the opening, said window unit, in an open position, being removed from the plane of the window opening, said mounting means comprising an elongated torsion spring having an arm secured thereto and projecting therefrom to be disposed at an angle corresponding to the angle between the lower member of the frame and an associated adjacent side member, means securing said torsion spring to the lower member including restraining means and journal means disposed in spaced relation along the length of said torsion spring, said journal means preventing relative movement of said lower member and torsion spring except about the longitudinal axis of the torsion spring and means pivotally securing the free end of the arm to the window unit adjacent a marginal edge thereof to pivot only about an axis parallel to the longitudinal axis of the torsion spring.

2. A window assembly as defined in claim 1 wherein said mounting means consists of a torsion bar having an arm projecting from each of the opposed ends thereof, the free ends of the arms being pivotally secured to the window unit at a position vertically above the center of gravity thereof.

3. A window assembly as defined in claim 1 wherein the torsion spring is an elongated torsion bar non-circular in cross-section throughout at least a portion of the length thereof and the means for securing said torsion spring to the lower member consistis of a journal disposed adjacent the arm permitting free rotation of the torsion spring and a restraining block preventing relative rotation between a portion of the length of the torsion spring and said lower member detachably securable to the spring and movable therealong to vary the effective length of the spring, said journal and restraining block being disposed in spaced relationship along said torsion bar.

4. A window assembly as defined in claim 1 wherein said window unit includes a sub-frame consisting of a pair of extruded aluminum solid sections detachably joined together and having a pair of flanges defining a groove therebetween to receive a flange projecting from the marginal edge of the window frame.

5. A window assembly as defined in claim 4 including a thermal barrier interposed between the members of the sub-frame.

6. A window assembly as defined in claim 5 including a further flange projecting outwardly from the sub-frame and thereby providing means for concealing the torsion spring and arm in a window closed position.

7. A window assembly comprising a window frame, a window unit and a mounting assembly securing said window unit to said window frame, said mounting assembly comprising a torsion bar, a pair of spaced parallel arms projecting outwardly from said torsion bar adjacent opposed ends thereof, means securing said torsion bar to said window frame along one edge of the latter including a journal and restraining block disposed in spaced relation along the length of the torsion bar and means pivotally securing the free end of each arm to respective ones of opposed marginal edges of the window unit.

8. A window assembly as defined in claim 7 wherein said mounting assembly includes an additional torsion bar having a pair of spaced parallel arms projecting therefrom, said additional torsion bar being secured to the window unit along an edge opposite to the marginal edge of the window frame to which the other torsion bar is secured and similarly including a journal and restraining block disposed in spaced relation along the length of the torsion bar, the free ends of each of the arms being pivotally secured to said window frame.

9. A window assembly as defined in claim 8 wherein the window frame and window unit each include a pair of flanges thereon disposed in abutting relation in a window closed position to define a channel circumscribing the window unit in a window closed position, said mounting assemblies being disposed within said channel and thereby concealed in a window closed position,

10. A window assembly comprising a window frame, a window unit and a mounting assembly securing said window to said window frame whereby the window is movable selectively to open and close a window opening defined by the window frame and in the open position, said window unit being removed from the plane of the window opening, said mounting assembly comprising a torsion bar having at least one arm projecting therefrom and pivotally secured adjacent the free end thereof to the window unit at a position vertically above the center of gravity thereof when the window is positioned vertically, said torsion bar being secured to the window frame along one edge thereof by a journal and a restraining block disposed in spaced relation along the length of the torsion bar, said journal being located intermediate the arm and the restraining block.

11. A window assembly adapted to be mounted substantially in a vertical plane comprising a window frame including a spaced lower and upper pair of parallel members interconnected by a pair of spaced side parallel vertical members to define a window opening, each of said members comprising a pair of shaped metallic members detachably joined together and having a flange projecting inwardly, said flange terminating at a marginal edge in a seal engaging member; a window unit including a glazing portion and a sub-frame, the latter comprising a pair of extruded aluminum members detachably secured together and having a thermal barrier interposed therebetween, said sub-frame having a groove receiving said seal engaging member of the glazing portion, a seal disposed in said groove and interposed between the window frame and window unit, said sub-frame having a further outwardly directed flange in spaced relationship with respect to said groove and mounting means disposed therebetween, said mounting means comprising a torsion bar secured to the lower member and having a pair of arms proecting therefrom to be disposed adjacent opposed marginal edges of the closing unit, means for securing the torsion bar to the lower member comprising a pair of bear ings disposed respectively one adjacent each arm and permitting free rotational movement of the torsion bar and means disposed intermediate said bearings for securing said torsion bar rigidly to said lower member of the frame, said means being relatively movable along a selected length of the torsion bar and means for pivotally securing the free end of each of the arms to the sub-frame to be concealed behind said further flange of the sub-frame in a window closed position.

12. A window assembly as defined in claim 11 including a further mounting means comprising a torsion bar secured to the window sub-frame adjacent the upper end of the window unit and having a pair of arms projecting downwardly therefrom and pivotally secured at the free ends thereof to the window frame.

13. A window assembly comprising:

(a) a window frame including a member circumscribing a window opening and having a pair of flanges projecting unequal distances thereinto, said flanges being disposed in spaced relation in a direction normal to the plane of said opening,

(b) a window unit including a glazing portion and a sub-frame circumscribing said glazing portion, said sub-frame having a pair of flanges projecting outwardly therefrom and disposed to be substantially in abutting relationship with respective one of the window frame flanges in a window closed position, the flanges on the window frame and the sub-frame defining a channel circumscribing the window unit in a window closed position, and

(c) a mounting assembly securing said window unit to said window frame, and disposed in said channel in a window closed position, said mounting comprising:

(i) a torsion bar,

(ii) a pair of spaced, parallel arms projecting outwardly from said torsion bar adjacent opposed ends thereof,

(iii) means securing said torsion bar to said window frame along one edge of the latter including a journal and restraining block disposed in spaced relation along the length of the torsion bar, and

(iv) means pivotally securing the free end of each arm to respective ones of opposed marginal edges of the window unit.

14. A window assembly as defined in claim 13 including a cooperating tongue and groove on respective ones of associated flanges of the window unit, window frame and a gasket interposed therebetween in a window closed position, said tongue and groove and gasket extending about the entire periphery of said window unit.

15. A window assembly comprising a window frame having a spaced lower and upper pair of members interconnected by a pair of spaced side members to define a window opening, a window unit and means for mounting said window unit to said frame selectively to open and close the opening, said window unit, in an open position, being removed from the plane of the window opening, said mounting means comprising an elongated torsion spring having an arm secured thereto and projecting therefrom to be disposed at an angle corresponding to the angle between the lower member of the frame and an associated adjacent side member, means securing said torsion spring to the window unit including restraining means and journal means disposed in spaced relation along the length of said torsion spring, said journal means preventing relative rotation of said window unit and torsion spring except about the longitudinal axis of the torsion spring, and means pivotally securing the free end of the arm to one of the spaced side members to provide for relative pivotal movement of the arm and the side member about an axis parallel to the longitudinal axis of the torsion spring.

16. A window assembly as defined in claim 15 wherein said mounting means includes a torsion bar having 'an arm projecting from one end of said bar and being disposed substantially at right angles thereto.

17. A window assembly as defined in claim 15 wherein the torsion spring is an elongated torsion bar noncircular in cross-section throughout at least a portion of the length thereof, and the means for securing said torsion spring to the window unit consists of a journal disposed adjacent the arm permitting free rotation of the torsion bar with respect to said window unit and a restraining block preventing relative rotation between a portion of the length of the torsion spring and said window unit detachably securable to the spring and movable therealong to vary the eifective length of the spring, said journal and restraining block being disposed in spaced relationship along said torsion bar.

References Cited UNITED STATES PATENTS 2,831,219 4/1958 Nelson 49-205 2,878,531 3/1959 Benham 49-386 2,960,733 11/ 1960 Nida 49-40 1 2,984,517 5/1961 Farrow et al 49-386 X 3,091,819 6/1963 Wheeler et al. 49-386 FOREIGN PATENTS 1,263,748 5/ 1961 France.

DAVID J. WILLIAMOWSKY, Primary Examiner. KENNETH DOWNEY, Examiner.