Collision-safeguarded Latch Mechanisms For Slidable Sashes

Abstract

A collision-safeguarded latch mechanism is disclosed for slidable sashes. The latch is extendible from one sash, to engage with a keeper on the other sash, when the sashes are closed; but a latch-retainer mechanism is employed to prevent the latch from being extended when the sashes are relatively displaced in the open condition thereof. The latch may be operated by a handle-actuated toggle mechanism, and may be locked in the latched position thereof by a magnetically actuated pinlock mechanism which is released by a key.

Description

FIELD OF THE INVENTION

This invention relates to latch mechanisms for slidable sashes; and more particularly to a latch mechanism of this nature which is equipped with a latch that is extendible from one sash, to engage with a keeper on the other sash, when the sashes are closed, but safeguarded against collision with the other sash when the sashes are opened.

BACKGROUND OF THE INVENTION INCLUDING CERTAIN OBJECTS THEREOF

A paired sliding window sash assembly is often fastened by a latch which is extendible from one sash, to engage with a keeper on the other sash, when the sashes are closed. One object of the present invention is to provide an extendible latch for such assemblies which is safeguarded against collision with the keeper sash, when the sashes are relatively displaced in the open condition thereof. Another object is to provide a latch mechanism of this nature in which the latch is prevented from being extended when the sashes are in the open condition thereof. A still further object is to provide a latch mechanism of this nature which is of simple and durable construction, and pleasing in appearance; and in which the latch can be locked in the latched position thereof by a lock mechanism which is released by a key. Other objects will become apparent from the description of the invention which follows hereafter.

SUMMARY OF THE INVENTION

These objects and advantages are realized by a collision-safeguarded latch mechanism of our invention wherein the latch is extendible from one sash, to engage with a keeper on the other sash, when the sashes are closed, but a latch-retainer mechanism is employed to prevent the latch from being extended when the sashes are relatively displaced in the open condition thereof. The latch may be operated by a handle-actuated toggle mechanism, and may be locked in the latched position thereof by a magnetically actuated pinlock mechanism which is released by a key.

In preferred embodiments of the invention, the latch retainer mechanism comprises a latch-retainer pin which is biased into a stop position with respect to the latch, when the latch is withdrawn from the extended position thereof and the sashes are relatively displaced in the open condition thereof. The retainer pin is displaced against the bias thereon by the keeper sash when the sashes are closed. In the displaced condition, the pin allows the latch to be extended into engagement with the keeper.

The latch may be stabilized in the extended and withdrawn positions thereof by a spring-loaded toggle linkage which is actuated by a handle. The handle may have a rectilinear vertical motion.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood by reference to the accompanying drawings wherein:

FIG. 1 is a part perspective view of a paired sliding window sash assembly, showing the meeting stiles and a collision-safeguarded latch mechanism thereon;

FIG. 2 is a part cross-sectional view through the latch mechanism when the latch is in the latched condition thereof;

FIG. 3 is a part cross-sectional view along the line 3-3 of FIG. 2;

FIG. 4 is a part cross-sectional view of the latch mechanism as the latch is being withdrawn from the latched position thereof;

FIG. 5 is another part cross-sectional view of the latch mechanism when the latch is fully withdrawn and the sashes are parted from one another; and

FIG. 6 is a part cross-sectional view of a similar latch mechanism which is equipped with a locking device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, it will be seen that the principal components of the latch mechanism 2 are mounted in a narrow block casing 4 which is installed upright in the cavity 6 of a hollow tubular rail 8 forming the meeting stile of the inside sash 10. In vertical section, the casing 4 has a stepped outline and blocked-in upper and lower wall sections 12 and 14, with a corbelled, open-ended bore 16 therebetween. The casing is installed between the inside and outside faces 8' and 8" of the stile, and protrudes outside each face, there being a lateral clearance 18 (FIG. 3) between the sashes so that the rearward protrusion 20 of the casing does not interfere with the relative movement thereof. The clearance 18 is concealed, however, by oppositely directed flanges 22 and 24 on the stile 8, and the stile 26 of the outside sash 28, the latter flange 24 being L-shaped to project toward the rearward protrusion 20 of the casing. The sidewalls 4' and 4" of the casing are laterally flanged at the vertical face of the forward protrusion 30, and an elongated, complementally slotted handle 32 with a parallelepipedal configuration, is slidably engaged over the face 30 of the casing to track up and down on the flanges 30'. The motion of the handle 32 operates the latch mechanism 2, although there is provision for preventing this motion when the sashes are unlatched and opened, as shall be explained hereinafter.

The operating components of the latch mechanism 2 include a flanged and arcuately stepped crescent latch 34 which is pivotally mounted on a hinge 36 that is horizontally secured across the bore 16 between the sidewalls 4' and 4" of the casing. The flanged rear portion 34' of the latch is housed against the inner wall 4" of the casing, and the hinge 36 is disposed in the bore 16 so that the latch swings between an extended position outside of the casing, as in FIG. 2, and a withdrawn position inside of the bore, as in FIG. 5. In the extended position of the latch, the flange 38 thereon interengages with a keeper element 40 on the stile 26 of the outside sash 28, thus preventing relative motion between the sashes. In the withdrawn position, the sashes are free to slide in the opposite directions of the arrows 42 in FIG. 3.

The latch 34 also has a slot 44 in the stepped nose portion 34" thereof, and a pair of hooked indentations 46 and 48 in the curved lower edge of the flanged rear portion 34' thereof. The slot 44 is substantially oppositely disposed from the tail end 38' of the flange 38, with respect to the angular positions of the same on the latch. The indentations 46 and 48 are angularly spaced from the flange end 38', and from one another, by angular segments of the latch 46' and 48', respectively.

The latch 34 and handle 32 are interconnected by a spring-biased toggle linkage 50 which operates the latch in reverse direction to the handle, and effectively stabilizes each member at the close of the operation. Fixedly interconnected with the handle is a yoke 52 which extends on a perpendicular into the bore 16 of the casing from the back of the handle. A pin 54 loosely the size of the slot 44 in the latch, is trunnioned between the arms 52' of the yoke and slidably engaged in the slot. In addition, a toggle link 56 is pivotally mounted at one end on the pin 54, and slidably engaged at the other end in a hole 58 in the hinge 36 of the latch. The pivotal end of the link has an enlarged head 56', and a coiled spring 60 is caged about the link between the hinge 36 and the shoulders 56" of the head. Thus, when the latch is in its upwardly inclined, latched position of FIG. 2, the spring 60 operates to retain the yoke 52 and the handle 32 in a raised abutted position against the upper wall section 12 of the casing. Similarly, when the latch is in its downwardly inclined, unlatched position of FIG. 5, the spring 60 retains the yoke and handle in a depressed position against the lower wall section 14. Between the two positions, the spring 60 maintains the latch and handle in an unstable condition, and they tend to snap into either the raised handle position of FIG. 2, or the depressed handle position of FIG. 5, depending on the direction of instability from the centered position of FIG. 4.

When the sashes 10 and 28 are open, the latch 34 is retained in the withdrawn position thereof by a stepped, spring loaded retainer pin 62 in the casing. The pin 62 is horizontally disposed in the bore 16, at a point in the rearward protrusion 20 of the casing, below the latch and opposite the corbel 16' of the bore. One end 62' of the pin is slidably received in a cylindrical recess 64 in the corbel, and has an enlarged tubular cross section so that a coiled spring 66 can be caged therein to bias it in the relatively outward direction from the corbel. The other end 62" of the pin is relatively reduced in cross section, and projects through and beyond a hole 68 in the opposite wall 4" of the casing, so as to be exposed to the right angular flange 24 of the outside sash 28. When the sashes are closed, the flange 24 displaces the pin 62 inwardly of the casing, thus placing the reduced end portion 62" of the pin in the path of the latch 34. When the sashes are opened, the spring 66 displaces the pin against the opposite wall 4" of the casing, thus placing the enlarged end portion 62' of the pin in the path of the latch.

The right-hand angular segment 48' of the latch in FIGS. 2, 4, and 5, is radially dimensioned about the hinge 36 so that the notch or indentation 48 thereof engages with the enlarged portion 62' of the pin, as in FIG. 5, when the latch is rotated counterclockwise. When the enlarged portion 62' of the pin is displaced from the wall 4', however, the angular segment 48' of the latch sweeps past the reduced portion 62" of the pin. See FIG. 4. Thus, when the sashes are open, and the flange 24 of the outside sash is detached from the pin, the latch cannot rotate into the path of the sash. On the other hand, when the sashes are closed, and the stiles of the same have met in the condition of FIG. 1, the flange 24 on the outside sash displaces the pin 62 from the path of the latch so that it can be operated. Still, however, the left-hand angular segment 46' of the latch is radially dimensioned so that the notch or indentation 46 thereof provides a stop for the latch. See FIG. 2.

FIG. 6 illustrates a similar latch mechanism 2' in which the latch 70 can be locked in the latched position thereof. Certain elements of the embodiment in FIGS. 1--5 have been omitted to simplify the illustration; however, it is apparent that the features of the two embodiments can be combined when desired.

In FIG. 6, the forward protrusion 72 of the casing 74 has a vertical slot 76 in the lower step 72' thereof. The slot 76 receives a plate key 78 which is notched in turn to receive a spring-loaded detent ball 80 that is housed in a horizontal bore 82 in the casing opening onto the interior of the slot 76. The detent ball 80 operates to retain the key 78 in the slot 76 at a point in which a strong permanent magnet 84 embedded in the front face thereof, releases a magnetically actuated pin lock 86 on the handle. The opposing faces 74' and 88' of the casing 74 and the handle 88 have recesses 90 and 92 formed therein, in the same vertical plane as the magnet 84 of the key 78. The recesses 90 and 92 are disposed to be horizontally aligned with one another when the handle 88 assumes its upper position. The recess 90 in the handle has a fixed permanent magnet 93 in the pit thereof which is oppositely disposed and weaker than the force of the key magnet 84. A magnetic pin 94 is slidably engaged in the mouth of the recess 90, and the polarization of the pin 94 is opposed to that of the magnets 84 and 93, so that when the handle 88 is in its upper position, the pin 94 is ejected into the recess 92 of the casing, in the absence of the key 78, but when the key is inserted and engaged in the slot 76, the greater force of its magnet 84 drives the pin 94 back into the pit of the handle recess 90. Thus, so long as no key is engaged in the slot, the latch can be locked against movement in the latched position thereof. Yet when the key is inserted, the latch can be used freely in either direction without locking the mechanism, since the magnetic pin 94 remains in the recess. A hole 96 in the key enables it to be withdrawn.

The lower step 72' of the casing, the handle 88, and the key 78, are all constructed of nonmagnetic material such as aluminum, brass or the like, so as to not interfere with the locking action of the pin 98.

Claims

What I claim is:

1. In a planar window assembly, a pair of parallel sliding sashes having meeting stiles which are opposed to one another across the plane of the assembly when the sashes are closed, and a collision-safeguarded latch mechanism on the stiles including a crescent latch which is journaled on a fixed hinge extending parallel to the plane of the assembly in one of the stiles, to pivot between positions in which the latch is retracted within and extended without the one stile, respectively, a keeper on the other stile which is engageable by the latch in the extended position thereof when the sashes are closed, and a latch-retainer pin reciprocably mounted in the one stile on an axis parallel to the plane of the assembly, which is biased into a position wherein the latch is estopped by the pin from pivoting into the extended position thereof, but which is axially displaceable against the bias thereon to another position wherein the latch is free to pivot into the extended position thereof, there being a portion of the pin projecting from the one stile on a parallel to the plane of the assembly, and means on the other stile which are operable to displace the pin into the aforesaid other position thereof as the sashes are closed.

2. The planar window assembly according to claim 1 wherein the latch-retainer pin has relatively diametrically enlarged and reduced portions thereon, and is biased into a position in which the relatively enlarged portion thereof is disposed athwart the pivotal path of the latch.

3. The planar window assembly according to claim 1 further comprising a handle on the one stile which is movable in a vertical path and pivotally interconnected with the latch to cause the latch to pivot in response to the vertical motion thereof, and a spring-loaded toggle mechanism which is pivotally mounted on the handle and slidably engaged with the latch to bias the latch into each of the retracted and extended positions thereof.

4. The planar window assembly according to claim 3 further comprising a magnetically actuated pinlock mechanism which is interposed between the handle and the one stile and released by a key.

5. The planar window assembly according to claim 1 wherein the pin displacement means takes the form of a flange which projects across the plane of the assembly from the other stile to engage the pin as the sashes are closed.