CA1320242C - Externally mounted latch for slidable sash window - Google Patents

Abstract

ABSTRACT
A pre-assembled latch for mounting externally on the header of a pivotal sash window of a double-hung sash window assembly. The latch includes a housing having a spring-biased latch bolt normally providing a protruding bevelled formation for engaging a guide rail of the window assembly.
The housing has means integral therewith for retaining the latch bolt operably assembled in the housing and the latch bolt has means cooperating with the housing for retaining the spring means in biasing association with the latch bolt.

Description

:~2 ~ ~2 EXTERNALLY MOUNTED LATCH FOR SLIDABLE SASH WINDOW

This invention relates generally to a manually opera-tive latch for a window sash of a double-hung window assemb-ly and more particularly, to a novel latch constructed to be supplied as an assembled operable latch ready for mounting externally on the top header of a window sash.
A double-hung window assembly includes a window frame and a pair of window sashes reciprocal vertically in guide rails of the master frame jamb of the window assembly. Such a window sash also can be pivotally mounted in the window frame. Normal vertical movement of the window sash is maintained by latch mechanisms located at opposed corners of the wlndow sash. Such a latch mechanism will include a latch bolt or slider which can slide along the guide rails and which, while engaged in the guide rails, prevents pivot-lng of the window sash. When the latch bolt is retracted from the guide rail, the wlndow sash can be pivoted on suitably installed pivot pins which usually engage sash balance mechanisms of the assembly.
The window sash can be formed either of extruded plastic frame members or metal frame members ~olned at corners to form a generally rectangular frame in which the glazing is mounted. In U.S. Patent Nos. 4,553,353, 4,578,903 and 4,622,778 are disclosed latch mechanisms in which the latch bolt or slider i9 located on the interior of the header member of the sash frame and a control button is accessible externally of the header member for operating the 13~2~2 latch. In each instance, the latch includes coil springs normally biasing the latch bolt into engagement with the op-posing guide rail. It will be seen that these latches can-not be pre-assembled for shipment to the window manufacturer ready for installation as a complete or assembled unit with the coil spring already in place. Thus, these latches are supplied in knocked-down assembly and hence entail a labor expense factor in their installation attributable to the as-sembly procedure required for installation.

U.S. Patent No. 4,622,778 disclosed a latch for a window sash which is mounted externally on the header member of the window. However, this latch also is not capable of belng supplied as an assembled unit ready for installation.
The conflguration of the individual parts of the latch does not provide for their assembly and shipment as a complete unlt ready for installatlon. Consequently, this latch necessitates labor time involvement for its assembly and ln-stallatlon.
The latch of U.S. Patent No. 4,622,778 also includes a "connector member" of L-Shape configuration which has a dual function, one of whlch is to maintain the latch bolt and coil ~prings in place for operatlon. A prior art latch for external mounting on the header member is specifically de-scribed and shown herein which does not use such a connector member. In this latch structure, there ls no connector mem-ber which has a flat part to hold the coil springs and bolt in place for assembly. Con~equently, in such a prior latch, the parts are shipped knocked-down and are to be assembled 1 32~2~

in situ prior to installation of the header member.
Here, the coil springs and latch bolt are placed in a cap or cover member and are required to be retained in place manually by the assembler. Then, the unit must be manipulated by inversion for placement flat on the header so that the header surface can function to keep the coil springs and latch bolt in operable assembly in the cover or cap. This manipulative procedure requires speed and dexterity in order to keep the coil springs from dislodging before the latch parts can be secured to the header.
The latch embodying the invention enables the latch to be supplied to the window manufacturer as a completely assembled unit ready for installation on the header member of the window sash.
An aspect of the invention is as follows:
In a pivotal window sash adapted for installation in a master frame of a double-hung sash window assembly having opposed, vertically extending guide rails to enable vertical reciprocal sliding movement of the sash in the master frame while cooperatively engaged with the guide rails, the sash having a header, a base and a pair of stiles cooperatively connected together at adjacent extremitie~ thereof to ~orm a rectangular sash frame; a manually operable latch adapted to be installed as a prea~sembled unit on an exterior surface o~ the header for releasably securing said sash to said master frame to permit pivotal movement of said ~ash and comprising:
a housing including a top wall having an access opening therethrough a pair of opposing end walls, one of said end walls having a passageway therethrough;
a latch bolt slidably received in said housing and having a beveled end aligned with and reciprocal in said passageway and arranged to be ~r . . ._ 2 ~ 2 engaged in a guide rail for locking the window sash against pivotal movement;
said latch bolt having an opening therethrough with a peripheral edge therearound;
spring means in said housing and engaging said latch bolt normally to bias said beveled end into said guide rail;
said top wall having means integral therewith and depending therefrom for engaging and retaining the latch bolt in operable assembly in the housing and permitting reciprocal sliding movement thereof said engaging means including a post which extends through said bolt opening and a retainer member extending laterally therefrom and extending over said opening peripheral edge at least in said normally biased position to retain said bolt in ~aid housing; and said latch bolt having means integral therewith for engaging said spring means and retaining said spring means in operable assembly in the housing.
The preferred embodiment of this invention now will be described, by way of example, with reference to the drawings accompanying the epecification in which:
FIG, 1 is a ~ragmentary front elevational view of a double-hung window aesembly having the latch embodying the invention installed on a window eash o~ the assembly;

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132~2~2 FIG. 2 is a fragmentary perspective view of a window sash in a pivoted open position and displaying the latch embodying the invention installed;
FIG. 3 is a vertical sectional view taken through the length of the latch as shown installed in FIG. 2;
FIG. 4 is an exploded perspective view of the latch embodying the invention which is illustrated in FIG. 2;

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FIG. 5 is a bottom perspective view of the assembled latch illustrated in FIG. 4, but showing the coil spring being installed therein;
FIG. 6 is a bottom perspective view of the latch illustrated in FIG. 5 with portions broken away to show the spring installed;
FIG. 7 is a top plan view of a modified embodiment of the assembled latch embodying the invention;
FIG. 8 is a bottom plan view of the assembled latch illustrated in FIG. 7;
FIG. 9 is a top plan view of the assembled latch illustrated in FIG. 4;
FIG. lO is a bottom plan view of the assembled latch illustrated in FIG. 9 and shown locked against slidlng movement.
FIG. 11 ls a bottom plan view of the latch illustrated in FIG. 7 with the latch bolt slightly modified and locked agalnst sliding movement;
FIG, 12 is a bottom plan similar to FIG. 11 and showlng the bolt unlocked for sliding movement;
FIG. 13 is a bottom plan view o a prior art latch assembled preparatory to installation on the header member.
Briefly, there will be described hereinafter a latch for external mounting on the header member of a pivotal window sash which i8 provided already assembled and ready for installation. The latch i8 comprised of a housing, a latch bolt or slider and spring means. The latch bolt has lip formation meanR integrally formed therewith constructed 2~2~2 and arranged to retain the spring means in place in the housing. Further, the housing has cooperating engagement means for preventing inadvertent separation or dislodging of the latch bolt from the housing during sliding movement of the latch bolt.
FIG. 1 illustrates partially a representative window of the so called double-hung window sash assembly. Such an as-sembly includes a main jamb frame 20 within which is slidab-ly mounted a pair of double hung sashes 22 and 24 fitted with suitable glazing. Both the frame 20 and sashes 22 and 24 can be formed of several different materials, such as metal or strong and rigid plastic materials well known in this field. For purposes of this invention, the sashes 24 and 22 are pivotal relative to the frame 20 to permit clean-ing and other required maintenance thereof.
The maln frame 20 and the sashes 22 and 2~ preferably are fabrlcated from elongate framing members of hollow conflguratlon in transverse cross-sectlon for well known reasons of welght economy and thermal lnsulatlon advantages.
The exact constructlon of maln frame 20 is not critlcal for achievlng the advantages of this invention. The vertlcal structural members of the frame 20 wlll mount sash balances (not shown) which will cooperate with plvot pins (not shown) installed on the sashes 22 and 2~ to permit desired pivotal movement of the sashes relative to the master frame. Fur-ther, these vertical structural members of the frame 20 wlll present guide rails facing toward a contlguous sash with which the latch mechanism embodying the inventlon operates.

13~2~2 A typical gulde rail is designated 26 in FIG. 2 for the pur-pose of describing this invention. The guide rail 26 would be formed in a side jamb 27 of the jamb frame 20.
Referring to FIGS. 1 and 2, a sash 22 is generally rec-tilinear in configuration and is comprised of a top header 28, a base 30 and a pair of side members or stiles, one of which is illustrated at 32. The stiles or side members 32 are ~ointed at their extremities to contiguous extremities of the header and base members, as seen at 34, to provide the sash frame of desired size and configuration. The ~ointed corners of the sash are maintained by suitable fasteners and brackets of well-known commercially available types. It will be appreciated that the upper sash 24 will be of like or similar construction. The glazing 36 is con-ventionally lnstalled in a sash frame.
Referring to Fig. 13, a prior art latch is illustrated and de~ignated by the reference numeral 1. The latch 1 is provided with a houslng 2, an access opening 3, a bolt 4 havlng a beveled latch formation at one end 5 and an ovate finger pull opening 6, as well as a pair of springs 7 secured between rectangular bolt wings 8 and spring stop members 9. During normal installation practice, the housing 2 is placsd on its back as shown in Fig. 13 and the bolt 4 and springs 7 are operationally positioned therein. To in-stall the header 28 of a window sash 22, it will be neces-sary to manually hold the springs in place and rapidly lnvert the latch for placement flat on the sash header 28.
Care must be taken so that the springs 7 and latch bolt 4 do - ~32~2~2 not dislodge from the housing. Thls 1s a labor-intensive operation and time is lost in production where these parts are dislodged.
The latch embodying the invention is designated gener-ally by the reference character 40 ln FIG. 2. The component parts of the latch 40, as seen in exploded view of FIG. 4 include a cover or housing 42, a latch bolt 44 and a coil spring 46. The houslng 42 and latch bolt 44 are plastic molded members of suitably strong synthetic resin, such as polystyrene, for instance. The latch 40 is seen installed externally on the header 28 of the sash 22 in FIG. 2 and ex-posed for manual operation thereof.
Referring to Figs. 3 and 4, the housing or cover 42 is rectangular in configuration and has a planar top wall 48 having a pair of depending, spaced apart posts 50 and 52 integral therewith. The posts 50 and 52 each have openings therethrough for accommodating a self-threading fastener 54 for fastening the latch 40 to a header 28. Depending from top wall 4B are depending 81de wall flanges 56 and 58 connected by a depend-ing end wall flange 60. Each flange 56 and 58 has a rlght angle wall segment 62 at its free end, the segments 62 faclng toward and spaced from one another to deflne a pas-sageway 64 for passage of the engagement end 65 of the latch bolt 44. The post 52 is seen ~oined to the end wall 60.
The post 50 18 ln closer proxlmlty to the passageway 64 and opposlng same on a line centered between segments 62.
Top wall 48 has an elongated oval or cartouche-llke ac-cess opening 66 therein located somewhat medially in sald L J. --7--~c~2~2~
wall 48. The circular opening 68 in top wall 48 serves to accommodate the rotatable lock element 70 which will be de-scribed in greater detail.
The post 50 has a latch bolt retainer member 72 in-tegral therewith and e~tending partially across the opening 66 in a direction toward the end wall flange 60. Extending at right angles from the side wall flanges 56 and 58 and toward one another are the spaced apart short wall segments 73 and 74. The segments 73 and 74 are located between the posts 50 and 52 and do not intercept or reach into the open-ing 66. Integral with the segment 74 is a spring stop member 75 which extends in a direction toward the end wall 62 of side flange 58 and terminates far short of the end wall 62.
As seen in FIG. 4, the short metal coil spring is designated 46. The selected length for the spring 46 will be amplified.
The latch bolt 44 is an integral, planar member with particular formations provlded from end-to-end thereof for achievlny speclfic functions. The entlre upper surface 76 of the latch bolt 44 i8 planar, smooth and uninterrupted ex-cept for certain through-slot openings ~rom the surface 76.
The latch bolt 44 also has a substantially planar lower sur-face 78.
Latch bolt 44 has a beveled end or latch formation 82, through whlch extends an ovate slot 83. Extendlng outwardly from opposite sldes of the latch bolt are the wings 84 and 85 and located between the extremities of ovate slot 83.

1320~2 Extendlng inwardly from slot 83 is an undercut segment 86 which opens to a second ovate actuator slot 87. The oppo-site end of the latch bolt 44 is designated 88 which is slightly tapered in its surface 90 opposite the top wall 80 and toward the extremity 92 which is less thick than the re-mainder of the latch bolt 44.
Referring to Figs. 4 and 5, the latch bolt 44 is de-signed to be posltioned within the cover 42 so that the latch formation 82 pro~ects through the passag~way 64, the post 50 is located within the slot 83, and the latch bolt retainer member 72 slidably engages the undercut segment 86.
The bolt 44 is adapted to be snap-fit into the cover 42 for reclprocal linear sliding movement therein.
The latch bolt 44 has a laterally extending lip forma-tion 94 which i6 flush with the lower surface 78 and extends from the wing B5 toward the extremity 92 and terminates far short thereof at an end 96. The axial length of the lip 94 18 Qelected to be substantially less than the linear dis-tance between wall segment 62 and wall segment 74. The lip 94 also 18 less thlck than the latch bolt so as to provide a retainer overhang formation for the spring 46 as will be de-scribed.
The wings 84, 85 each have an end face 98, which on the wing 85 functions as a stop for the end 100 of the spring 46. The end 102 of the spring 46 opposlte the end 100 ls placed against the spring stop member 75. In Figs. 4 and 6, the member 75 is shown Joined to the flange 58, however the member 75 may be located alternatively in slightly spaced , ~,, i~hi,L~-; ~ g 2 ~ 2 relationship from the inner face of the ~lange 58 to allow mating engagement with the end 102 of the spring 46 as shown in Fig. 10. The spring 46 is sufficiently long so that when the bolt 44 is installed beneath the cover 42, the spring 46 exerts a biasing force which maintains the bolt 44 project-ing through passageway 64.
Once installed within the cover 42, the spring 46 is located in a pocket 106 defined by the underside of the cover 42, a side edge of the bolt 44, the end face 9B, the spring stop 75 and the inside face of the depending side flange 58. The lip 94 is designed to prevent the escape of the spring 46 from the pocket 106 prior to the installation of the latch 30 upon the surface 28 of the sash 22, 24.
The truncated end 88 of the bolt 44 is designed to engage the lock 70. The lock 70 includes a circular base 112 upon which is fixed an actuator boss 114. A top 116 of the actuator boss 114 is provided with a suitable recess 118 (seen best ln Fig. 9) adapted to receive the operational end of a tool, such a~ the ~traight edge of a screwdriver. The base 112 has a depending flange 120 whlch can engage the truncated end 88 along an opposlng arcuate side 122 when the bolt 44 is retracted against the normal bias of the spring 46. In Fig. 4, the lock 70 is shown in the retracted or release condition where the planar face 123 of the flange 120 engages the truncated end 88 of the bolt ~ and the beveled end 65 o~ the bolt 44 is retractable through the passageway 64 to release the latch 40 from engagement wlth the frame 20. The boss 116 i9 frictlon fitted into the lock :~3~2~2 aperture 68 for axial rotation therein. The base 112 engages an annular recess 124 in the underside of the cover 42.
Referring to Fig. 5, the latch 40 is shown with the bolt 44 retained within the cover 42 by the retaining member 72 and the lock 70 is in the locked position, wherein inad-vertent retraction of the bolt 44 is prsvented. The spring 46 is shown being inserted into the pocket 106 over the end 96 of the lip 94. In Figs. 6 and 10, the spring 46 is shown in the operational position within the pocket 106 and retained therein by the lip 94, and wherein the bolt 44 is biased in the extended condition and is locked against move-ment to the retracted condition by the lock 70.
An alternate embodiment of the latch 40 is shown in Figs. 7 and 8 and designated generally by the reference character 140. The latch 140 shares several structural fea-tures wlth the latch 40 and these have been indicated with correspondlng reference numerals. The latch 140 differs from the latch 40 ln that the lock 70 is ab~ent therefrom, as evidenced by the altered cover 142, and the ovate slot 87 on the bolt 44 described previously has been replaced with a finger flange 132 pro~ectlng vertically from the bolt 144 for manual manipulation thereof. Equivalent alternate ac-tuator configurations are contemplated. In addition, the undercut segment 186 is an elongated version o~ the segment 86.
Referring to Figs. 11 and 12, a further alternative em-bodiment of the latch 40 is illustrated, and deslgnated gen-erally by the reference character 240. The latch 240 is distinguishable from the latch 140 in that a lock 70 is provided thereto. The lock 70 is shown in the locked condition in Fig. 11 and in the release or retracted condition in Fig. 12, having been rotated axially in the direction indicated by the arrow 232 to permit the end 65 of the bolt 144 to be retracted within the passageway 64 to release the sash 22, 24 for pivoting action within the frame 20.
In addition, Figs. 11 and 12 illustrate an important feature of the bolt retaining member 72. In Fig. 11, which depicts the locked or extended condition of the latch 240, the retaining member 72 is completely inserted within the undercut segment 186. In this position, the bolt 144 is securely retained within the cover 42. It should be noted here that although the bolt 144 shown in Fig. 11, as well as the bolt 44 ln Flg. 10 are shown wlth the wings 84, 85 abut-ting the interior face of the wall segments 62 ad~acent the passageway 64 to termlnate the linear movement of the bolts 40, 140 this is not the only means of terminating that move-ment, In fact, it has been found that the movement of the bolts 40, 140 in the extended conditlon may be terminated by the end 89 of the undercut segments 86,186 contacting the base 77 of the retalning member 72 (seen in Fig. 4).
Referring to Fig. 12, the latch 240 ls shown ln the release or retracted condltlon, wlth the truncated end 88 of the bolt 144 engaglng the planar side 123 of the lock base ,5, -12-~ c3;~ 2 flange 120, and the beveled end formation 82 is retracted within the passageway 64. It is evident that in this posi-tion, the beveled free end 80 of the retaining member 72 is still engaged in the undercut segment 186 to retain the bolt 144 within the cover 42.
Although not specifically shown, the retaining means can be one or more depending members from the top wall, such as, a pair of clip members which engage edges of the latch bolt.

While preferred embodiments of the invention have been disclosed, it will be understood that tha invention may be otherwise embodied wlthin the scope of the appended claims.
Minor variations in the structure and in the arrangement and size of the various parts may occur to those skilled in the art without departing from the spirit and scope of the claims appended hereto.

Claims (13)

1. In a pivotal window sash adapted for installation in a master frame of a double-hung sash window assembly having opposed, vertically extending guide rails to enable vertical reciprocal sliding movement of the sash in the master frame while cooperatively engaged with the guide rails, the sash having a header, a base and a pair of stiles cooperatively connected together at adjacent extremities thereof to form a rectangular sash frame; a manually operable latch adapted to be installed as a preassembled unit on an exterior surface of the header for releasably securing said sash to said master frame to permit pivotal movement of said sash and comprising:
a housing including a top wall having an access opening therethrough a pair of opposing end walls, one of said end walls having a passageway therethrough;
a latch bolt slidably received in said housing and having a beveled end aligned with and reciprocal in said passageway and arranged to be engaged in a guide rail for locking the window sash against pivotal movement;
said latch bolt having an opening therethrough with a peripheral edge therearound;
spring means in said housing and engaging said latch bolt normally to bias said beveled end into said guide rail;
said top wall having means integral therewith and depending therefrom for engaging and retaining the latch bolt in operable assembly in the housing and permitting reciprocal sliding movement thereof said engaging means including a post which extends through said bolt opening and a retainer member extending laterally therefrom and extending over said opening peripheral edge at least in said normally biased position to retain said bolt in said housing; and said latch bolt having means integral therewith for engaging said spring means and retaining said spring means in operable assembly in the housing.

2. The latch of Claim 1 wherein said spring retaining means comprises a laterally extending lip formation overlying the spring means.

3. The latch of Claim 2 wherein said lip formation is spaced from the top wall to define a pocket for said spring means, said pocket having an opening thereinto at one end thereof through which the spring means can be installed in the pocket.

4. The latch of Claim 1 wherein said latch bolt is provided with at least one laterally projecting wing formation, said wing formation arranged to engage an inner surface of said housing so as to maintain the alignment of said bolt within said housing.

5. The latch of Claim 1 wherein said retainer member comprises an elongate member parallel with and spaced from the plane of said top wall, said latch bolt having an undercut segment intermediate its ends and having said elongate member engaged with said segment.

6. The latch of Claim 1 and including locking means for releasably securing said latch bolt in said biased condition.

7. The latch of Claim 6 wherein said locking means is actuable from the exterior of said top wall.

8. The latch of Claim 7 wherein said locking means is a member mounted on said top wall to depend from the underside thereof for axial rotation thereon and adapted to engage an end of said bolt opposite said beveled end to prevent movement thereof in a direction opposite to said bias for retracting said beveled end from the guide rail.

9. The latch of Claim 1 wherein said latch bolt is provided with an additional opening therein which is accessible through said access opening in the top wall.

10. The latch of Claim 9 wherein said access opening in the top wall and said additional latch bolt opening each can accommodate a finger therein.

11. The latch of Claim 1 wherein said latch bolt includes an upstanding actuator member for manually moving the latch bolt.

12. The latch of Claim 1 wherein said housing has means for installing the pre-assembled unit on said header surface comprising a second post depending from the underside of said top wall having a bore therethrough for accepting a fastener capable of retaining the unit secured on the header.

13. The latch of Claim 1 wherein said retainer member comprises an elongate member which is supported by said post.