GB2296035A

GB2296035A - Latching device

Info

Publication number: GB2296035A
Application number: GB9602355A
Authority: GB
Inventors: Richard E Schlack; David Milne
Original assignee: Southco Inc
Current assignee: Southco Inc
Priority date: 1993-04-06
Filing date: 1993-09-03
Publication date: 1996-06-19
Anticipated expiration: 2013-09-03
Also published as: GB9602356D0; GB2296034A; GB2296526A; GB2296526B; GB2296035B; GB2296036A; GB2296034B; GB9602353D0; GB2296036B; GB9602354D0; GB9602355D0

Description

2296035 LATCHING DEVICE

1. Field of the Invention

The present invention relates generally to latching devices and more particularlyto fasteners which are operable through rotation by a user for securing a door, panel or the like in a closed position relative to a corresponding frame.

2. Background of the Invention

Presently, there are a number of latching devices known in the art which are operable by rotation of a shaft or the like for securing two panels or a panel against a corresponding frame. Generally, fasteners of this type include a latching pawl which is provided extending from a shaft disposed in a bore in the latch housing. In operation, rotation of the shaft corresponds with a movement of the latching pawl to its latched position.

Generally, the fasteners of this type require varying degrees of rotation of the shaft for operation of the latch. One type are "quarter turn" fasteners which require a 90 rotation for operation of the latch. Such latches usually consist of a housing, drive stud, spring and pawl which are installed within an aperture formed in a door panel. However, one problem with such prior art designs is that water, dust and other matter is able to pass freely through the latch and into the interior compartment of the door panel, thus into contact with the contents contained therein.

The spring which is positioned proximate the top of the latch between the drive stud and the housing is required during operation to support the load which is being applied by the latch. This increased stress applied by the latch adversely affects the springs operation and durability.

The installation of such latches can oftentimes be a rather time consuming and complicated process for some individuals. For instance, existing 1 4C designs require that the installer correctly determine the proper orientation for the pawl on the shaft during installation. Furthermore, the designs which have been developed in order to hasten the installation process have proven to adversely affect latch operation. In particular, some designs allow a mounting nut to be slid over the pawl and onto the housing in order to accommodate installation within a panel aperture. However, these prior art designs require either a necked down section in the pawl, which reduces the strength of the pawl, or an extra loop in the pawl, which is rather difficult to manufacture.

The present invention has been developed in view of the foregoing and to overcome the deficiencies of the prior art,

SUMMARY OF THE INVENTION

The present invention provides an improved latching device as set

Claims

out in Claim 1, which is adapted to be mounted in an aperture formed in a

door panel for releasably retaining the door against a corresponding frame. The device includes a housing which is adapted for being received within the door panel aperture. The housing is included with a substantially axial bore extending therethrough. A drive member is also included which has a substantially elongated shaft which is received within the housing bore for rotational movement. A biasing means is included which provides a frictional resistance to the drive member upon its rotation. A means for limiting the rotational movement of the drive member shaft is also included which is positioned between the housing and the drive member. A pawl means is also provided associated with the drive member shaft and adapted for rotational movement corresponding with the movement of the drive member for engaging the frame int he secured position.

2 M.

An object of the present invention is to provide a latching device capable of restricting the passage of water, dust or other matter through the latch.

A further object of the present invention is to provide a latching device which is durable in use and yet provides a smooth latching operation.

It is a still preferred object to provide a latching device in which the 10 parts are few and which is relatively simple to install.

These and other objects of the present invention will become more readily apparent when taken into consideration with the following description and the attached drawings.

is BRIEF DESCRIPTION OF THE DRAWINGS Fig 1 is a perspective view, partly broken away, showing a door panel having a latching device according to the present invention mounted 20 therein.

Fig 2 is a sectional elevational view of the device of Fig 1 taken along the line of 2-2.

Fig 3 is an exploded view of the device shown in Fig 2.

Fig 4 is a plan view of the device of Fig 3 taken along the line 4-4.

Fig 5 is a plan view of the device of Fig 3 taken along the line 5-5.

3 a Fig 6 is a plan view of the device of Fig 3 taken along the line 6-6.

Fig 7 is a plan view of the device of Fig 3 taken along the line 7-7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings in detail wherein like reference numerals indicate like elements throughout the several views, there is shown in Fig 1, a perspective view, partly broken away, of a door panel having a latching device 10 (hereafter referred to as a pawl assembly 10) according to the present invention mounted therein, and in a latched position engaging a cabinet frame 110. As most clearly illustrated in Figs 2 and 3, the major components of the pawl assembly 10 -I-)f the present invention are a drive member 12, a housing 14, a biasing 4 F the ieans 16 and raw! =eans --ig. _3 shows an exnloded view of r)awl assemblv!0 shown in Fig. 2; in Fig. 2 is illustrated a sectional eievational v,-ew of the Dawl assembly of Fig. I taken along the line 2-2. The drive member 12 as shown preferably is a drive stud manufactured of die cast zinc with a variety of different finishes, however other materials can also be used for the same purpose. The drive member!2 as illustrated includes, as portions thereof, a drive flange 20 and a substantially elongated shaft extending inwardly therefrom. The substantially =longated shaft as shown includes a first portion 22, a second zortion 24, -= zhird portion 216 and a threaded fourth oortion 28.

The first portion 22 extends inwardly from the flange 20 and is comprised having a substantially circular cross-section. The second portion 24 extends inwardly from the first portion 22 and includes a substantially circular cross-section of a diameter less than the diameter of the first portion 22. The third portion 26 has a non-circular, generally irregular shaped cross-section which extends inwardly from the second portion 24.

As best seen in the plan view of Fig. 4, taken along the line 4-4 of Fig. 3, the cross-section of the third portion 26 preferably includes a configuration which is generally rectangular with one substantially radiused corner. The threaded fourth portion 28 extends inwardly from the third portion 26 as shown. As seen illustrated in Figs. 3 and,,4, an at least one projecting member, preferably comprising the projecting members 3Da-30d, are provided extending outwardly from a top surface of the second - 5 OL -::orz--cDn 24. and in e--iaaaemenr with a side surface cf the third portion 26. The drive flange 20, as best illustrated in Fig. 4, J ts -s provided having a generally elongated channel --2 within In this su--.4ace. mreferably adjacent its first portion 22. Jllustraced embodiment, the drive member 12 is also included with an elongated slot 34 in its outer surface, which is adapted to receive a corresponding key member (not shown) for rotation of the drive member 12 during operation of the pawl assembly lo.

As best illustrated in Fig. 3 and the plan view of Fig. 5 i-=ken alona the 1ne 5-5 of Fic. 3, the housing 14 includes.:!-.ere-in a housing -f- lange 36 which is adapted to abut the outer surface of the door panel 100 on installation. The housing flange 36 includes extending outwardly therefr= a protruding member 44 which is adapted to be received within the channel 32 of the drive member!2, as shown in Fig. 2. In addition, extending inwardly from the housing flange 36 is shown a threaded area 38 and a substantially conical second area 40, adjacent the threaded first area 38. As best seen in the plan view of Fig. 6 taken along the line 6-6 of Fig. 3, the substantially conical third portion 40 includes therein at least one aperture formed within its inner side, preferably the two apertures 42a and 42b are provided formed therein for a purpose described below. Preferably, the housing 14 is manufactured of die cast zinc with chemical, protective film, however other suitable materials can also be used for manufaCture of this component.

- 6 As shown:.--1 12, zhe biasing means!6 is a siDrina member of an irregular configuration, and comiDrises at least one but.:referablv a series of four alternatina raised and lowered surfaces extending around the circumference thereof. The biasing means 16 also,includes a substantially circular through hole therein. As best illustrated in the plan view of Fig. 7 taken along the line 7-7 of Fig. 3, the biasing means 16 further ncludes at least one receptacle formed therein, preferably the four receptacles 46a-46d are provided. The receptacles 46a-46d are adapted to be received by the projecting members 30a-30d, resnecz-vely, for fixing the 1Dosition of the biasing means 16 relative to the drive member 12. In operation, the raised surfaces of the biasing means 16 are adapted to releasably engage the apertures 42a-42b of the housing 14 in the manner described below. Preferably, the biasing means 16 is manufaccured of hardened steel with a zinc alloy plate, however other suitable materials can also be provided- The pawl means 18, as best seen in Figs.3 and 7, comprises a generally elongated pawl member which includes a through hole 48 formed therein. Preferably, the shape of through hole 48 corresponds in configuration with the configuration of the cross-section of third portion 26 of the drive member 12. As such, the pawl means 18 when the through hole 48 is properly aligned is receivable onto..the third portion 26 of the drive member 12, as shown in Figs. 2 and 7. In addition, the pawl means 18 includes a stepped section proximate its distal end (not shown) which extends zoward the door ranel 100 when mounted, and which engages the frame 110 in the latched position. The pawl means 18 ureferably is manufactured of steel, with a zinc alloy plate, although cther suitable materials can also be used for this purpose.

A fastening means such as a nut 50 is also included which is receivable onto the threaded fourth portion 28 of the drive member 12 for retaining the components of the pawl assembly 10 together as a unit.

As indicated earlier, the pawl assembly io of the present _nvention is adanted to be mounted in the door panel 100 for engaging the frame 110 in a closed position. Preferably, a mounting means such as a nut 52 is received onto the threaded first area 38 of housing 14 for mounting the pawl assembly 10 in the aDerture of the door panel 100. The door panel 100 and frame!10 can be fabricated from any suitable type of material for enclosing various equipment or apparatus which may be installed therein (not shown). in the illustrated embodiment, the pawl assembly 10 is shown mounted in a door 100 for engaging a frame 110, however the pawl assembly 10 can have other applications as well, for example where two door panels engage in a closed position.

In operation of the pawl assembly 10, rotation of the drive member 12 causes a corresp9nding rotation of the pawl means 18 between an unlatched and latched position engaring the frame 110. In the present embodiment, the drive member 12 is shown having zhe elonaaced slot 34 formed therein, -which is adapted to receive a corresnondingly configured driving tool for rotation thereof. Although in the illustrated embodiment the elongated slot 34 is shown, other shanes can also be utilized for this same purpose, for example L square shape, star shape, triangular shape, etc. which would also be engageable by a corresponding tool. In certain other applications, a handle, knob or similar device can be secured directly onto the drive member 12 for rotation, rather than employing the separate driving tool, as illustrated in the present embodiment.

-',ks hest illustrated in Figs. 1 and 4, the rotation of the pawl means 18 is limited by the position of the protruding member 44 in the substantially elongated cbannel 32. Specifically, the protruding member 44, when the pawl assembly 10 is in its fully latched position of Fig. 1, is in engagement with a first end of the channel 32. In its fully unlatched position, the protruding.nemner 44 is rotated counterclockwise into engagement with the second end of the channel 32. Preferably, the pawl assembly 10 when fully unlatched is in a position 900 from the latched position. In the present embodiment, the arrangement of the protruding member 44 and channel 32 provide a 900 rotation of the pawl assembly 10. However, in other circumstances, if desired, the length of the elongated channel 32 can be varied to provide an alternate degree of rotation of the pawl assembly 10.

The pawl assembly 10 possesses several advantages over conventional pawl assemblies. A particular - 9 =dvanr acre -s at::he present ---"vencaon is adapted to restrict zhe passage c-f -water, dust or other matter through the latch and 'nto the incerior compartment of the door. As best shown in Figs. 2 and ---, zhe drive flange 20 of the drive member 12 is sized at least.to completely c over the outer surface of housing flange 36, which forn a seal for improving the sealability o4- "he latch. An O-ring 54 can be provided the second portion 24 and abutting the first portion 22 the adjacent of the drive member i2, and a sealing washer can be positioned proximate:he underside of the drive flange 20 (not shown) in order to 7; rovide addizi--nal sealing of the pawl assembly 10. An additional benefit is that the larger sized flange also provides a broad bearing area which provides for a smoother latch operation.

Another advantage of the pawl assembly 10 is that the amount of stress imposed on the spring 16 is greatly reduced which will work to extend the operable life span of the device. As best illustrated in Fig. 3, the biasing means 16 is in a position between the housing 14 and pawl means 18 and in engagement with these two components. Due to this position between the housing 14 and pawl means 18, the biasing means 16 does not experience any of the load being applied by the latch, and therefore does not become overstressed, or possibly deformed in order to support that load. During operation, the biasing means 16 takes up any play in the latch which is oft-entimes present due to manufacturing tolerances. Preferably, the biasing means 16 - operates to force the comoonencs of the pawl assembly 10 --ogether, which results in a frictional resistance upon" the drive member 12 during rotation between the latched and unlatched positions. This arrangement provides for smoother operation of the pawl assembly 10 and greatly reduces the chance that the biasing means 16 will become permanently deformed during operation.

In addition, the assembly 10 provides another advantage over the prior art in that the biasing means 16 also operates as a detent as the pawl means 18 is moved into its 900 latched and unlatched positions. As indicated earlier, the raised surfaces of the biasing means 16 are adapted to engage the apertures 42a and 42b formed in the bottom of the housing 12 in the latched and unlatched positions, thereby acting as a detent. Preferably, the four raised sections of the biasing means 16 are in an arrangement wherein two of the raised sections are diametrically opposing and engage the slats 42a-42b in the latched position, and the other two raised sections are diametrically opposing and engage slots 42a- 42b in the unlatched position. This arrangement is particularly advantageous since the biasing means 16 is adapted for two operations; as a spring member for taking up additional play in the latch and as a detent when in the latched and unlatched positions of the pawl.

Furthermore,. another advantage of the present pawl assembly over conventional pawl assemblies is that a quicker and easier installation can be accomplished without also requiring a more 11 - -;ijff--lcult and coseiv -ianufaczjri.na process, or a reduction in the strength of the latch. Specifically, as indicated earlier, the zhrough hole 48 of the Dawl means 18 is shaped to coincide with the cross- sectional configuration of the third portion 26 of the drivemember 12. This ensures chat the pawl means 18 can only be installed properly onto the drive member 12 in one position of the pawl means 18. While in the present embodiment, the shape of the through hole 48 and third portion 26 of the drive member 12 are generally rectangular with a substantially radiused corner portion. any suitable shaDe or configuration can be utilized for:.he same turDose. As a result, -t is the design of the pawl assembly 10 which dictates the proper orientation of the pawl means 18, rather than the installer of the latch.

In addition, in some instances, preferably in panels less than 6mm thick. an assembled pawl assembly can be installed as a unit directly through the aperture of the door panel 100. This provides for a quicker installation procedure for the latch. Specifically, following installation of the pawl assembly 10 through the aperture of the door panel 100, the mounting nut 52 is received over the pawl means 18 and onto the housing 14 for mounting of the pawl assembly 10 in the aperture of the door panel 100. It is the conical portion 40 at the distal end of the housing 14 which allows the mounting nut 52 to be received from around the pawl means 18 and directly.,onto to the housing 14 for mounting of the pawl assembly 10.

It will be recognized by those skilled in the art that changes 12 - imay be made by the above-described embodiments of the invention with departing from the broad inventive concepts thereof. For example, the apertures 42a-42b which are formed in the housing and the raised sections of the biasing means 16 can be comprised of any suitable configurations for this same purpose. in addition, the pawl means 18 can be formed having any suitable length or any suitable amount of offset in its stepped section.

13 CLAIMS I. A latching device for mounting in an aperture formed in a door panel for releasably retaining the door against a corresponding frame, the device comprising:

a housing adapted for being received within the aperture of the door panel and including extending therethrough a substantially axial bore, the housing further including a housing flange adapted for engaging an outer surface of the door panel when received therein, the housing flange including as portions thereof an outer and an inner surface; a drive member including a substantially elongated shaft adapted for being received within the bore of the housing for rotational movement relative thereto between a latched position and an unlatched position of the device, the drive member further including a drive flange in engagement with and sized at least to completely cover the outer surface of the housing flange, whereby the housing flange and drive flange form a seal for restricting the passage of matter through the latching device a biasing means adapted for providing frictional resistance to the drive member upon rotational movement thereof, limitation means for limiting the rotational movement of the drive member shaft; and pawl means associated with the drive member shaft adapted for rotational movement corresponding with the movement of the drive member shaft for engaging the frame in a secured position when the 25 device is in the latched position.
2. The device according to Claim 1, wherein the biasing means is provided between the housing and the pawl means.
3. The device according to any preceding claim, wherein the housing 14 is generally conical in shape adjacent its end distal of the housing flange for receiving a mounting member, the mounting member being received onto the housing for securing the latching device in the aperture of the door panel, whereby the mounting member upon installation thereof is 5 slidable over the pawl means and onto the housing.
4. The device of any preceding claim, wherein the biasing means is engaged between the housing and the pawl means.
5. The device according to any preceding claim, further including detent means provided between the housing and the biasing means for releasably retaining the biasing means in at least one position of rotation relative to the housing upon rotation of the drive member.
6. The device according to Claim 5, wherein the housing includes at least one aperture formed therein and the biasing means includes at least one raised section thereon adapted for releasably engaging the at least one aperture, whereby upon a first rotation of the drive member by an operator, the raised section of the biasing means will be moved to engage the aperture of the housing for retaining the biasing means, and upon a second rotation of the drive member by an operator, the raised section of the biasing means will disengage the housing aperture for releasing the biasing means.
7. The device according to any preceding claim, further comprising retaining means provided between the drive member and the biasing means adapted for fixing the position of the biasing means relative to the drive member.
8. The device according to Claim 7, wherein the retaining means comprises at least one projecting member extending outwardly from the drive member shaft adapted for receiving at least one receptacle formed in the biasing means.
9. Thedevice according to any preceding claim, wherein the housing includes at least two apertures formed therein and the biasing means includes at least two raised sections thereon adapted for releasably engaging the biasing means in at least two positions of rotation relative to the housing, the first position corresponding to the latched position of the device and the second position corresponding to the unlatched position of the device.
10. The device according to any preceding claim, wherein the pawl means comprises a generally elongated pawl member adapted for being received by the drive member shaft in only one orientation of the pawl member.
11. The device according to Claim 10, wherein the drive member shaft includes at least one portion thereon having a generally non-circular shaped cross-section, and wherein the pawl member includes therein a through hole formed corresponding in configuration with and adapted to be received by the generally non-circular portion of the drive member shaft.
12. The device of any preceding claim, wherein the biasing means includes at least one series comprising a raised surface alternating with a lowered surface, the raised surface engaging the housing and the lowered surface engaging the pawl means to provide the frictional resistance to the drive member upon rotational movement thereof.

16