SUMMARY OF THE INVENTION

This invention relates to a combined slide and tilt-lock and a counterbalance spring for a vertically slidable and tiltable window sash.

U. S. patent 3,789,549 to Yip discloses a slide for a window sash which is received in a vertically elongated trac in an adjacent side of the window frame. A helical spring extending vertically along the track acts between the window frame and the slide to counterbalance the weight of the window sash and window pane. A locking member with a cam- shaped periphery is rotatably mounted on the slide for adjustment between a position in which it does not impede th up or down sliding movement of the window sash and a locking position wedged in the track, which it occupies when the sas is tilted into the room. In its locking position, the locking member prevents up or down displacement of the windo sash in the window frame.

The present invention is directed to a novel and improved simplified arrangement for the same general purpose. In accordance with the present invention, a one-piece member acts as both a slide for guiding the up and down movement of the window sash and as a tilt-lock for preventing such movement when the sash is tilted with respect to the window frame. The counterbalance spring for the window sash is a thin, flat, elongated spring leaf which is wound into a spiral at its upper end and is anchored there to the window frame. The lower end of this spring is attached to the combined slide and tilt-lock for the window sash. Between its spirally-wound upper end and its lower end, the unwound thin, flat length of the spring extends closely down along o wall of the slide track in the window frame and is concealed and protected by the frame.

If desired, one or more additional springs of the same ty may be mounted in the window frame directly above the first spring, and the unwound length of each additional _.sprir

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springs may extend down next to the unwound length of the first spring in the slide track for attachment to the combin slide and tilt-lock. The springs do not interfere with each other or with the up and down movement of the window sash, a the provision of more than one such spring at each side of t window sash enables a heavier sash to be counterbalanced properly.

A principal object of this invention is to provide a nove and improved vertical slide and tilt-lock and counterbalance spring arrangement for a window sash.

Another object of this invention is to provide such an arrangement in which a single slide member with a cam-shaped periphery acts as both a vertical slide and a tilt-lock for the window sash. Another object of this invention is to provide such an arrangement having a counterbalance spring in the form of a thin, flat, elongated spring leaf with a spirally-wound uppe end fastened to the window frame and with its unwound thin, flat length below its upper and concealed and protected by t window frame, and its lower end fastened to the combined sli and tilt-lock member.

Further objects and advantages of the present invention will be apparent from the following detailed description of the two presently-preferred embodiments shown in the . accompanying drawings.

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DESCRIPTION OF THE DRAWINGS

Figure 1 is an elevational view of a closed window having a frame and upper and lower sashes equipped with springs and tilt-lock slides in accordance with a first embodiment of th invention;

Figure 2 is a vertical cross-section taken along the line 2—2 in Figure 1 at one side of the window frame;

Figure 3 is a horizontal cross-section taken along the li 3—3 in Figure 1; Figure 4 is a horizontal cross-section taken along the li 4—4 in Figure 1;

Figure 5 is an exploded perspective view showing one of t cam-lock slides and the mounting for one of the springs acti between the window frame and one of the window sashes in Figure 1;

Figure 6 is a fragmentary exploded perspective view showi one of the cam-lock slides attached to the lower end of a spring, the track in the window fr._me which receives this cam-lock slide and spring, and the adjacent lower corner of the window sash;

Figure 7 is a fragmentary vertical section taken along th line 7—7 in Figure 2 and showing the frame-mounted upper en of the spring;

Figure 8 is a perspective view of the Figure 1 window wit the window sashes tilted into the room;

Figure 9 is a view similar to Figure 2 and taken along the line 9—9 in Figure 8, showing the position of the cam-lock slides when the window sashes are tilted into the room; and Figure 10 is a view generally similar to Figure 2 and showing a second embodiment of the invention in which two springs are provided for each cam-lock slide.

Before explaining the disclosed embodiments of the present invention in detail, it is to be understood that the inventio is not limited in its application to the details of the particular arrangements shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.

DETAILED DESCRIPTION

Referring to Figure 1, a rectangular window frame is show having opposite vertical sides 11 and 12, a top piece 13 extending horizontally between the opposite sides 11 and 12 at their upper ends, and a bottom piece 14 extending horizontally between these sides at their lower ends. The t and bottom pieces are rigidly connected at their opposite en to the respective sides to provide a unitary, rigid window frame which may be mounted in an outside wall of a building a known manner.

The window has a rigid rectangular lower sash with opposi vertical sides 11a and 12a joined to a horizontal top piece 13a and a horizontal bottom piece 14a. This sash extends peripherally around and- supports a lower window pane 15. Th lower sash fits entirely inside the window frame, with the opposite sides 11a and 12a of this sash in close proximity t and inside the corresponding sides 11 and 12 of the window frame toward the inner (room) side of the frame.

The window also has a rigid upper sash with opposite vertical sides lib and 12b, a horizontal top piece 13b, and a horizontal bottom piece 14b, which extends around and supports an upper window pane 16. The upper sash fits entir inside the window frame, with the opposite sides lib and 12b of this sash in close proximity to and inside the correspond sides 11 and 12 of the window frame toward the outer (buildi exterior) side of the frame.

Both window sashes are slidable vertically in the window frame. Both sashes may be tilted from an upright vertical position (Figures 1 and 2) , in which they fit snugly inside the window frame, to a tilted position (Figures 8 and 9) , in which they extend down horizontally away from the window fra into the room for cleaning of the outside of the respective window panes.

Referring to Figure 4, the right side 12 of the window frame presents a vertically elongated inner track 17, which aligned with the lower window sash lla-14a, and a vertically elongated outer track 18, which is aligned with the upper window sash llb-14b. The inner track 17 is located closer t

inside of the building than the outer track 18.

The inner track 17 is of rectangular cross-section throu out its vertically elongated length. It is defined by an o end wall 19, which is at the laterally outward side of the track, away from the window sash, a pair of side walls 20 an

21 joined to the outer end wall 19 and extending perpendicul to it laterally inward toward the adjacent side 12a of the lower window sash, and a pair of aligned, flat, inner end li

22 and 23 which are joined respectively to the side walls 20 and 21 and extended perpendicular to the latter and toward each other. These lips 22 and 23 are closely spaced from th adjacent side 12a of the lower window sash and they terminat short of one another to define between them a vertically elongated opening 24 leading into the track 17 at its latera inward side (i.e., the side next to the adjacent side 12a of the lower window sash) .

The opposite (left) side 11 of the window frame is a mirr image of the right side 12 and it presents inner and outer tracks 17 and 18 which are mirror images of those in the rig side. Corresponding structural elements in the left side of the window frame are given the same reference numerals as those in the right side, and the detailed description of one side will suffice for both.

The vertically elongated inner track 17 in each side of the window frame receives a corresponding tilt-lock slide member 25 with a cam-shaped periphery, as shown in Figure 2. This slide member is fastened to the outer end of a rectangu shank 26, which extends horizontally into the bottom piece 1 of the lower sash and is bolted or otherwise rigidly attache to this bottom piece. In this manner, each slide member 25 rigidly coupled to the bottom piece 14a of the lower sash so that the lower sash and the two slide members 25 move up and down in unison and turn in unison in the window frame.

A respective leaf spring 27 of thin, flat cross-section h its lower end snugly received in a recess or groove 28 formed in the periphery of the corresponding slide member 25, as bes seen in Figures 5 and 6. The upper end of each spring is

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spirally wound and is fastened to the central hub 29 (Figure 5) of a corresponding mounting bracket 30. This mounting bracket is received in the slide track 17 about half-way up that side of the window frame, as shown in Figure 2. Referri to Figure 7, a screw 31 extends through the hub 29 of the mounting bracket 30 andhas its inner end screw-threaded into that side of the window frame. Consequently, the spring 27 has its spirally wound upper end rigidly mounted on that side of the window frame in the vertical track 17 above the slide member 25.

The unwound, vertically elongated, thin, flat length of the spring 27 extends down along the track 17 substantially contiguous to the inner side wall 20 of the window frame and completely behind the lip 22, so as to be concealed and physically shielded by the latter. The lower end of the spri 27 fits snugly in the peripheral recess 28 in the slide membe 25 and is anchored to the slide member by a pin or other suitable rigid fastening arrangement.

As shown in Figure 2, the slide member 25 has a flat segme 32 on its periphery which extends parallel to, and spaced fro the outer side.wall 21 of the track 17 in the rotational position which the slide member assumes when the lower sash extends vertically upright in the window frame. In this rotational position of the slide member 25 it presents a minimum diameter extending horizontally between the opposite side walls 20 and 21 of the track and it is easily slidable u and down along the track to guide the up and down movement of the lower sash in the window frame.

When the lower window sash is tilted into the room (Figure this causes the slide member 25 to rotate 90 degrees from the position shown in Figure 2 to the position shown in Figure 9. The horizontal diameter of the slide member 25 between the opposite side walls 20 and 21 of the window frame track increases progressively as it is so turned, so that the slide member becomes wedged tightly between the opposite side walls 20 and 21 of the track 17, locking the window sash against vertical movement in the window frame when the sash is tilted in to the horizontal position shown in Figure 9.

The slide member 25 is formed with a generally C-shaped groove 33 which is substantially concentric with its axis of rotation through the shank 26. This groove enhances the ability of the slide member to compress radially as its cam- shaped periphery is rotated into progressively tighter wedgi engagement with the opposite side walls of the track 17, as described. Preferably, the slide member 25 is of resilientl deformable plastic material.

The spirally wound spring 27 exerts an upward force on th window sash to counterbalance the combined weight of the sas and window pane in any vertical position thereof within the window frame.

The novel one-piece construction of each slide member 25 and its size and shape enable it to perform two' functions in the window: (1) in one rotational position, as a slide which is guided vertically along the corresponding track 17 to hold the lower window sash properly positioned in the window frame as the sash is raised or lowered; and (2) in a second rotational position, as a frictional lock which acts between the lower sash and the window frame to prevent the sash from being raised or lowered while it is tilted with respect to th window frame. As already explained, each counterbalance spri 27, because of its thin, flat cross-section, has its unwound length concealed- and protected by the window frame. The lips 22 and 23 of the window frame on opposite sides of the vertically elongated opening 24 leading into the track 17 confine the slide member 25 and the spring 27 in that track.

At the outer track 18 in each side 11 and 12 of the window frame, the frame construction is essentially similar to the construction already described in detail for the inner tracks 17. The outer tracks 18 are slightly offset laterally inward from the inner tracks 17, as shown in Figure 4. Structural elements of the window frame at the outer tracks 18 are given the same reference numerals, plus 100, as those for the inner tracks 17, so that the detailed description of these elements need not be repeated.

A spirally wound, thin, flat spring 127 acts between the window frame and a slide member 125 in each outer track 18 in

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the same manner as the corresponding elements 27 and 25 in each inner track 17 of the window frame. A mounting bracket 130 holds the spirally wound upper end of each spring 127 an is fastened by a corresponding screw 131 to that side of the window frame at the respective outer track 18; the lower end of each spring 127 is affixed to a corresponding slide membe 125, which has a cam-shaped periphery as already described i detail for the slide members 25 in the inner tracks 17.

The tilt-lock member 125 and springs 127 are essentially the same as the slide members 25 and springs 27 for the lowe sash, and therefore they need not be described in detail.

As long as the upper sash is vertically positioned in the window frame, the slide members 125 are freely slidable up a down along the respective outer tracks 18 to guide the upper sash when it is raised or lowered. When the upper sash is tilted horizontally into the room (Figures 8 and 9) , the sli members 125 become wedged tightly into frictional engagement with the opposite side walls 120 and 121 of the respective tracks 18, thereby locking the upper sash against movement vertically along the window frame while this sash is tilted in, as shown.

Figure 10 shows a second embodiment of the present invent which has two spirally wound, flat springs at each side of e window sash. This second embodiment is advantageous for heavier windows. ^• *

The window frame has a vertically elongated inner track i each side at the inside (i.e., toward the window sash) which slidably receives a slide member 25' having a cam-shaped periphery. The construction of the window frame at this tra is substantially identical to what has already been describe in detail. The slide member 25* is rigidly attached to the lower end of a flat leaf spring 27' , whose upper end is spirally- wound in a bracket 30' attached to this side of the window frame. A similar second bracket 230 is fastened to the window fr directly above bracket 30' and it holds the spirally wound. upper end of a second flat spring 227. This unwound length the second spring 227 extends down contiguous to the first

spring 27' at the side of the latter toward the room.

Both springs 27' and 227 are concealed and protected in t track and because of their flat configuration neither interferes with the other. More than two such springs may be provided for each slide member 25* , depending upon the weight of the window sash and window pane which is to be counterbalanced by the springs.

The outer sash in Figure 10 also is provided with two similar springs for the cam-shaped slide member at each side of the window. The arrangement here is substantially the sa as the one already described for the lower sash, and it has the same advantages.

If desired, more than two counterbalance springs may be provided at each side of each window sash. The vertically offset spirally wound upper ends of the springs and their thi flat unwound lengths down along the slide track in the window frame do not interfere with each other when the springs are arranged in multiples of two or more.

From the foregoing, it will be apparent that the present invention constitutes a novel and simplified arrangement of a tilt-lock slide and a counterbalance spring for a window sash in which the slide is of one-piece construction, serving both the function of a slide when the sash is vertical in the wind frame and the function of a lock to prevent up or down moveme of the sash when it is tilted. The counterbalance spring is concealed and protected by the window frame, and it is inherently adapted to be arranged in groups of two or more without interference between the springs in a group.

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