US3418018A

US3418018A - Magnetic latch

Info

Publication number: US3418018A
Authority: US
Inventors: Ivan L Marburger; Elmer A Haglund; Donald W Howell
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-10-21
Filing date: 1965-10-21
Publication date: 1968-12-24
Anticipated expiration: 1985-12-24

Description

Dec. 24, 1968 1 MARBURGER ETAL 3,418,018

MAGNETIC LATCH Filed oct. 21, 1965 s sheets-sheet 1 A 'IIIIIIIIIIIIII Hrranugf.

Dec. 24, 1968 1. L. MARBURGER ET AL 3,418,018

MAGNETIC LATCH Filed Oct. 2l, 1965 3 Sheets-SheetI 2 .L/wee A. ,Hiraaw/a, .DONALD 7W Hn/ELJ.,

Dec. 24, 1968 MAGNETI C LATCH Filed OCT.. 21, 1965 3 Sheets-Sheet 5 Y., 6. M m..o,.,m www V FJH W fw. i MMM VLO In;

United States Patent Office Patented Dec. 24, 1968 3,418,018 MAGNETIC LATCH Ivan L. Marburger, 1315 Tulare Way, Upland, Calif.

91786, Elmer A. Haglund, 1667 Deventer Drive,

La Verne, Calif. 91750. and Donald W. Howell,

311 Bowdoin Road, La Verne, Calif. 91750 Filed Oct. 21, 1965, Ser. No. 500,073 25 Claims. (Cl. 292-2515) ABSTRACT F THE DISCLOSURE A magnetic latch for releasably joining two members with the latch parts being in mutual contact with the parts in latching relation, with one latch part including a permanent magnet and the other latch part an armature thereby releasably joining the parts by magnetic attraction, with one of the latch parts secured on one member so that when the members are moved toward one another the other latch part contacts the other member in a gripping relationship that prevents the part and the member from separating when the latch is separated.

This invention relates generally to closure locking devices; more particularly, -the present invention relates to novel latches and to a unique method of installing the same.

As will appear from the ensuing description, the latches of the present invention may embody various types of latching actions, including both mechanical and magnetic actions. The invention is particularly suited, however, for magnetic latches. For this reason, the invention will be disclosed herein primarily in connection with magnetic latches.

In its broader aspects, the invention provides closure latches which embody a basic conventional latch structure including first and second latch parts and coacting latching means on these parts, whereby the latter are releasably joined by movement of the same into latching relation. The invention is concerned, primarily, with simplifying the installation of such latches. Ac-cording to usual installation procedures, the latch parts are secured by bolts, screws, or the like to a closure and its support, respectively, in such a way that the parts are properly aligned to register in latching relation when the closure is moved to its closed position. This method of installing latches is diicult and time consuming to accomplish, even for the skilled craftsman, owing principally to the ditculty of properly aligning the latch parts and driving the screws which secure these parts to the closure and its support or frame. Moreover, a screw driver, drill and/ or other tools are required for the installation. These tools may not always be readily accessible.

The present invention provides novel closure latches which are uniquely constructed in such a way as to permit quick and easy installation thereof even by the most unskilled person. Moreover, such installation may be accomplished without the aid of tools. The latches of the invention are thus vastly superior to those currently available. Of signicance is the fact that these advantages of the present latches are accomplished without any increase in the cost or complexity of the latches over conventional latches. As a matter of fact, the present improved latches are less complex and costly than the majority of the existing latches.

As noted earlier, the present improved latches may embody various types of latching actions, both mechanical and magnetic, but will be disclosed herein primarily in connection with magnetic latches. In a typical magnetic latch, the latching means comprises a permanent magnet on one latch part and a magnetically permeable armature on the other latch part. These latch parts are installed in such a way that the magnet and armature are brought into magnetic latching relation upon movement of the closure to its closed position. The closure is then releasably retained in this position by the magnetic attraction between the magnet and armature.

According to the present invention, one part of the latch, hereinafter referred to as the primary part, is rst secured to one member of a closure structure in such a way that movement of the closure, or door, of the structure to its closed position is effective to establish gripping contact between attachment means on the other latch part, hereinafter referred to as the secondary part, and the other member of the structure. This gripping contact joins the secondary latch part and its respective member of the closure structure in such a way that the force required to separate the same exceeds the force required to separate the two parts of the latch. In the case of a magnetic latch, the latter force is the force of magnetic attraction between the magnet and armature of the latch. Generally, the primary latch part is mounted on the support or frame of the closure structure and the secondary latch part is attached to the closure or door of the structure. If desired, however, these positions of the latch parts may be reversed.

According to the preferred practice of the invention, the latch element of one of the latch parts is adjustably mounted within a housing in such a way that this element is automatically longitudinally positioned in the housing, for proper latching engagement with the other latch part, when the closure of the closure structure is moved to its closed position to establish gripping contact between the secondary latch part and its respective member of the structure. In certain illustrative embodiments of the invention, means are provided for locking this adjustable latch element against movement relative to its housing in order to adapt the latch for use on a closure structure having a warped closure or door.

Various types of attachment means may be employed in the present latch for securing the secondary latch member to its respective member of the closure structure. In the illustrative embodiments of the invention, for example, this attachment means comprises a contact adhesive. Among the other attachment means which may be employed are prongs, pointed teeth, and the like.

lIt is evident at this point, therefore, that the invention provides a latch which may be quickly and easily installed on a closure structure by rst joining the latch part in latching relation, then mounting the primary latch part on one member of the structure, and nally moving the closure, or door, of the structure, to its closed position in such a way as to establish gripping contact between the attachment means on the secondary latch part and the other member of the structure. The latch parts are thereby automatically properly aligned for relative movement thereof into and from latching engagement during subsequent opening and closing movement of the closure.

A general object of the invention, therefore, is to provide novel latches of the character described and a novel method of installing the same on a closure structure.

It is an object of the invention to provide latches and an installation method of the character described wherein one latch part is initially mounted on one member of a closure structure and the other latch part is thereafter properly located on and secured to the other member of the structure by the simple expedient of moving the closure of the structure to its closed position.

Another object of the invention is to provide latches of the character described which may be installed without the aid of tools.

. An object f the invention is vto provide latches ofA the character described wherein the coacting latching means on the latch parts are automatically aligned and adjusted into proper latching relation during installation of the latches.

An object of this invention is the provision of latches of the character described which embody a magnetic latching action.

Other object-s, features and advantages of the present invention will become apparent to those versed in the art from a consideration of the following description, the appended claims and the accompanying drawings, wherein:

FIGURE l is a side elevation of a magnetic latch according to the invention and illustrates the latch in the course of its installation on a closure structure;

FIGURE 2 is a view similar to FIGURE l and illustrates the latch at the conclusion of the installation procedure;

FIGURE 3 is an enlarged section through the latch taken on line 3-3 in FIGURE 1;

EIGURE'4 is an enlarged perspective view of the latch in FIGURES l and 2;

FIGURE 5 is an exploded perspective view of the latch shown in FIGURES 1 through 4;

FIGURE 6 is a perspective view of a modified magnet which may be employed in the latch;

FIGURE 7 is a section through a modified magnetic latch according to the invention;

yFIGURE 8 is a longitudinal section taken through a modified magnetic latch according to the invention and illustrates the latch in the course of its installation on a closure structure;

FIGURE 9 is a view similar to FIGURE 8 showing the latch at the conclusion of the installation procedure;

IFIGURE 10 is a section taken on line 10-10 in FIG- URE 9;

FIGURE 1l is an enlarged perspective view of the latch in FIGURES 8 to 10;

FIGUR-E 12 is a longitudinal section through a further modied magnetic latch according to the invention;

. FIGURE 13 is a perspective View of a restraining element embodied in the latch of FIGURE 12;

FIGURE 14 is a perspective view of a further modified magnetic latch according to the invention;

FIGUR'E l5 is a view, in longitudinal section, of a further modified latch according to the invention;

FIGURE 16 illustrates the latch in FIGURE 15 after installation thereof on a closure structure;

FIGURE 17 is an exploded perspective view of the latch illustrated in FIGURES l5 and 16;

FIGURE 18 is a View, in longitudinal section, of a further modified latch according to the invention;

EFIGURE 19 illustrates the latch in FIGURE 18 during installation thereof on a closure structure; and

vFIGURE 20 is an exploded perspective view of the latch illustrated in IFIGURES 18 and 19.

The magnetic latch 20 illustrated in FIGURES' 1 through 5 of these drawings comprises primary and

secondary latch parts

22 and 24, respectively, adapted for attachment to a closure member 26 and its supporting member 28, respectively. As will appear presently, the latch is installed in such a Way that the

latch parts

22 and 24 are brought into latching relation when the closure member 26 is moved to its closed position of FIGURE 2. In the drawings, closure member 26 is the door of the cabinet and the member 28 is a shelf of the main cabinet body. The

parts

22 and 24 of the latch 20, when disposed in latching relation, are effective to releasably lock the door 26 in its closed position and to release the door for opening in response to the application of pre-determined opposing forces on the latch parts, as occasioned by pulling on the door.

The particular latch 20 illustrated is a magnetic latch wherein the coacting latch means on the latch parts 7 Y24 comprise a magnetically permeable armature element 3) and a permanent magnet element 32, respectively. The armature 30 is mounted on the door 26 and comprises a rectangular plate of mild steel or other magnetically permeable material. The armature plate has a mounting surface 34 facing the door 26 and a latching surface 36 facing away from the door. Applied to the mounting surface 34 is a'contact adhesive 38. As will appear shortly, various kinds of contact adhesives may be employed in the present latches.

The permanent magnet part 24 of the latch 20 comprises, in addition to the permanent magnet 32, a hollow rectangular housing 40 of nonmagnetically permeable material. Housing 40 has flat side walls `42 and edge walls 44. Magnet 32 is a laminated structure of flat rectangular shape including a center plate 46 and two outer plates 48 which are bonded or otherwise joined. The center plate 46 comprises a plastic or ceramic magnet and the two outer plates 48 comprise magnetically permeable plates constructed of mild steel, for example. Magnet 32 is slidably tted in the housing 40 and has an outer end extending beyond one end of the housing, as shown. This outer end of the magnet 'has a transverse latching surface 50 facing the armature plate 30. The armature plate is releasably joined to the outer end of the -magnet by the magnetic attraction Ibetween these elements.

Housing 40 has a mounting surface S2 to which is applied a contact adhesive 54. Adhesive 54 may be the same type as the adhesive 38 which is applied to the mounting surface 34 of the armature plate 30.

For reasons which will appear presently, it is necessary to limit relative movement of the magnet 32 in the `housing 40. This is accomplished vby restraining means 56 which act between the magnet and housing. Restraining means 56 comprise serrations or ratchet teeth 58 formed in opposite longitudinal edges of the magnet 32 and resilient detents or ta'bs 6l) punched out from and bent inwardly from the edge walls 44 of the housing into engagement with the serrations 58. The serrations 58 and tabs 60 are shaped to restrain the magnet 32 against outward movement from the housing 4l) wthile permitting inward movement of the magnet into the housing.

The illustrated magnetic latch 2G is installed yby--lirst securing the mounting surface 52 of the latch housing 40 to the underside of a shelf 28 in the installed position shown'. In this installed position, the latch 20 is so located that movement of the door 26 to its closed position is effective to establish seating or gripping contact between the inner surface of the door and the adhesively coated mounting surface 34 of the armature `plate 30. The door may be coated with a contact adhesive in the region of contact with the armature plate. In the case of the illustrated latch, attachment of the latch housing 40 to the shelf 28 is accomplished yby simply pressing the adhesively coated mounting surface 52 of the housing upwardly against the under surface of the shelf which may be also coated with a contact adhesive in the region of contact with the housing. The contact adhesive 38 applied to the mounting surface 34 of the armature plate is so selected that the seating or gripping contact which is established between the mounting surface 34 of the armature 30 and the door 26 by movement of the door to its closed position produces between the door and armature a permanent adhesive bond whose tensile strength exceeds the force required to separate the armature 30 and magnet 32. This force of separation, of course, is equal to the magnetic attraction between the armature and magnet.

When installing the latch 20 in the manner explained above, the magnet 32 is initially extended from the housing 40, as shown in FIGURE 1, and the latch-is so located on the shelf 28 that the magnet is forced back into the housing when the door 26 is closed, thereby locating the magnet and armature in proper latching relation. The restraining means 56 on the latch permit this inward movement of the magnet into the 'housing but restrain the magnet against outward movement from the housing under the action of the magnetic force between the magnet and armature when the door 26 is subsequently opened.

The illustrated latch 20, then, may Ibe quickly and easily installed Without the aid of any tools by the simple expedient of pressing the mounting surface 52 of the latch housing 40 against the shelf 28 and thereafter closing the door 26. During this procedure, the armature plate 30 is automatically properly aligned with the magnet 32 and is secured to the 'door 26, and the magnet 32 is automatically longitudinally positioned in proper latching relation to the armature, all in a single step.

FIGURE 6 illustrates a modified magnet 32a which may be used in the magnetic latch of FIGURES l through 5 in place of the magnet 32 illustrated therein. Magnet 32a is similar to magnet 32 in that the former, like the latter, is a laminated structure including a center plastic magnetic plate 46a and two outer magnetically permeable plates 48a. The edges of the magnet 32a, however, are not serrated, and the side edges of the center magnet plate 46a extend 4beyond ythe side edges of the outer magnetically permeable plates 48a. When the magnet 32a is installed in the latch housing 40, the housing tabs or detents 60 engage the extending marginal edges of the center magnet plate 46a in such a way as to permit inward movement of the magnet into the housing but restrain the magnet against outward movement from the housing, as before.

FIGURE 7 illustrates a modified magnetic latch 20h according to the invention. In this modified latch, the restraining means 56h for restraining the latch magnet 32b against outward movement from the latch housing 4Gb while permitting inward movement of the magnet into the housing comprises detent formations 60b on the inner surfaces of the housing edge walls 44h which engage the edge serrations or ratchet teeth 58b on the magnet. The latch housing 40b is constructed of plastic or other suitable material and is so designed as to provide the housing edge walls 44b with sufficient flexibility to yieldably retain the detents -60b in operative engagement with the serrations 58b. The serrations 58b and detent formations 60b are so shaped as to restrain the magnet 32h against outward movement relative to the latch housing 40b while permitting inward movement of the magnet into the housing. Latch 20b is otherwise identical to the latch 20 and is installed in the same way as the latter latch.

FIGURES 8 through 10 illustrate a further modified magnetic latch 20c according to the invention. This latter latch comprises a latch housing 40e having a bore in which is slidably fitted a cylindrical, rod-like magnet 32e. The outer end of this magnet may lbe rounded, as shown, for seating in a correspondingly rounded socket in the latching surface 36C of the latch armature 30C, thereby to provide a swivel action between the armature and magnet. This swivel action, while desirable, is not essential. Latch 20c` is equipped with restraining means 56C to restrain the magnet 32C against outward axial movement from the housing 40C while permitting inward axial movement of the magnet into the housing. This restraining means comprises an internally detented, friction washer 58e disposed within a transverse slot 60e in the housing 40e and frictionally receiving therethrough the magnet 32C. The mounting surfaces of the armature plate 30e and housing 40e have layers 38e and 54C, respectively, of a suitable pressure-sensitive, contact adhesive, as before, whereby the modified latch 20c may be installed in the same way as the first latch 20. The swivel action between the armature 30C and magnet 32e of the modified latch permits the armature to align itself flat against the door 26 during installation of the latch.

FIGURES 12 through 14 illustrate two further modified

magnetic latches

20d and 20e according to the invention. Latch 20d is similar to latch 20 and differs from the latter latch only in the construction of the restraining means 56d. This restraining means comprises a flexible strap 58d constructed of rubber or other resilient material and formed at its ends with wedging bead formations 60d. The strap is bent around the inner end of the latch magnet 32d, as shown, so that the beads 60d on the strap are disposed between the confronting side edges of the magnet 32d and the side walls 44d of the latch housing 40d. The side edges of the magnet are tapered so that they incline toward the adjacent housing side walls 44d in the direction of movement of the magnet, as shown. Accordingly, the restraining means 56d provides a wedging action between the magnet 32d and the housing 40d which restrains the magnet against outward movement from the housing while permitting inward movement of the magnet into the housing.

In the latch 20e, the latch housing 40e is constructed of plastic or other relatively soft material and the longitudinal side edges of the two outer magnetically permeable plates 48e of the latch magnet 32e extend beyond the side edges of the center magnetic plate 46e of the magnet. The restraining means 56e of the modified latch comprise pointed detents 58e which are struck upwardly from the longitudinal side edges of the outer magnet plates 48e so as to engage the housing 40e in such manner as to restrain the magnet 32e against outward movement from the latch housing 40e while permitting inward movement of the magnet into the housing.

The

latches

20e and 20d are used with armature parts similar to the armature part 22 of the latch 20 and are adhesively coated for installation in the same way as the latter latch.

It is evident that various types of contact adhesives may be employed on the present latches. Some of the adhesives which may be used, for example, are Eastman 910 adhesive and various structural adhesives such as the epoxy structural adhesive which is marketed by the Allaco Products Company under the name Minute Care. Various phenolic structural adhesives and other adhesives may also be employed. These adhesives may be applied to the mounting surfaces of the latch parts in any convenient Way. For example, the mounting surfaces may be directly coated with the adhesives. In the alternative, certain types of commercially available pressure sensitive tapes may 4be employed.

At this point, it is evident that the contact adhesive applied to the mounting surface of the armature of the latches described above provides an attachment or gripping means which is effective to join the armature to its respective supporting member of the closure structure when the armature is moved into initial seating or gripping contact with its supporting member during initial installation of the latches in the manner described earlier. As noted earlier, and hereinafter explained, various other types of attachment or gripping means for this purpose maybe employed in the present latch.

In the latch as described thus far, the restraining means which coact between the magnet and its housing are effective to resist or prevent longitudinal movement of the magnet in only one direction relative to the housing, i.e., in the outward direction, that is in the direction in which the magnetic force between the armature and magnet tends to move the latter when the closure or door of a closure structure mounting the latch is opened. In some cases, it is desirable to restrain the magnet against longitudinal movement in both directions relative to its housing. For example, during initial installation of a latch on a closure structure, or during subsequent movement of the closure or door of the structure to its closed position, the closure may be deformed or bowed toward the part of the latch which is mounted on the closure support or frame due to the application of excessive closing force on an unsupported portion of the closure. If the magnet is restrained against only outward longitudinal movement relative to its housing, this deformation or bowing of the closure may cause excessive inward movement of the magnet into its housing. In this case, the

magnet and armature will not enter into proper magnetic latching relation during subsequent movement of the closure to its closed position by the application of normal closing force to the closure. This problem can be avoided, obviously, by securing the magnet against inward longitudinal movement relative to its housing. The modified latches illustrated in FIGURES through 20 embody restraining means for thus positively restraining or positioning the magnet in its housing. These modified latches also embody a unique swivel action which permits the latch magnet to align itself flat against the armature.

The latch 100 illustrated in FIGURES 15 to 17 comprises a primary latch part 102 which is secured to the support or frame 104 of a closure structure and a secondary latch part 106 which is secured to the closure or frame 108 of the structure. Latch part 102 comprises a hollow rectangular housing 110 of non-megnetically permeable material. Housing 110 has longitudinally extending rows of spaced, internal serrations or grooves 112. Disposed within and movable longitudinally of the housing 110 is a laminated, permanent magnetic structure 114. This magnetic structure, or magnet :as it will be hereinafter referred to, comprises a center, permanent magnetic plate 116 and two outer plates 118 constructed of magnetically permeable material, such as mildv steel. The magnetic plate 116 is somewhat smaller than the outer magnetically permeable plates 118. The inner, confronting faces of the outer plates 118 have raised ribs 120 which serve to position the magnetic plate 116 relative to the outer plates. Projecting from the outer surfaces of the outer magnetically permeable plate 118, adjacent the inner edges of these plates, are coaxial journals 122. As may be best observed in FIGURES 15 and 16, the overall thickness of the three

plates

116, 118 is substantially less than the corresponding internal dimension of the magnet housing 110. The axial spacing between the outer end faces of the magnet journals 122 is just slightly less than this internal housing dimension.

Disposed in stradling relation to the inner end of the magnet 114 is la generally U-shaped magnet restraining or positioning clip 124 having

legs

126 and 128 which extend outwardly through the spaces between the magnet 114 and the upper and lower side walls of the magnet housing 110. These clip legs have journal bores 130 which rotatably receive the journals 122 on the magnet 114. Between the journal bores 130 and the inner, connecting bite portion of the clip portion 124, the

legs

126 and 128 are bent outwardly to form edges 132 which resiliently engage the inner surfaces of the adjacent side walls on the housing 110. The outer end of the upper clip leg 126 is bent upwardly, away from the magnet 114 and toward the 'adjacent upper side wall of the magnet housing 110, to form a resilient detent which is engageable with the internal serrations 112 on the magnet housing 110 to restrain the magnet 114 against left hand or outward movement relative to the housing. This detent, however, permits right hand or inward movement of the magnet relative to the housing. The lower leg 128 of the magnet positioning clip 124 is somewhat longer than the magnet housing 110, for reasons to be explained presently.

At this point, it is significant to note that the interengaging journals 122 on the magnet 114 and journal bores 130 in the magnet positioning clip 124 provide an effective pivotal connection between the clip and the magnet. The width of the permanent magnetic plate 116 between the longitudinal edges of the outer magnetically permeable plate 118 of the magnet, is somewhat less than the corresponding internal dimension of the magnet housing 110, whereby the magnet is capable of limited edge wise pivotal movement relative to the housing.

The armature .part 106 comprises a magnetically permeable armature plate 134. The left hand mounting surface of this plate bears a layer of contact adhesive 136, as in the earlier described latches of the invention.

The modified latch is installed on a closure structure in the same vway as described earlier in connection with the previous latches of the invention. Thus, the magnet 114 is extended outwardly from the magnet housing 110, as illustrated in FIGURE 15. The magnet housing is then secured to its respective supporting member 104 of the closure structure in such a way'that movement of the closure or door 168 of the structure to its closed position establishes seating contact between the door and the armature part 106 of the latch, as illustrated in FIGURE 16. During this closing movement of the door, the latch magnet 114 is driven inwardly into the housing 110 to a position wherein the magnet is disposed for proper latching engagement with the armature 106 during subsequent closing of the door 108. As in the earlier forms of the invention, the initial gripping contact between the armature 106 and the door 108 produces a permanent adhesive bond between the armature and door having a tensile strength exceeding the force required to separate the armature and magnet during subsequent opening of the door. Engagement of the outer, upwardly bent detent end of the upper clip arm 126 with the adjacent internal serrations 112 in the magnet housing 110 restrains the magnet 114 against outward movement relative to the housing during subsequent opening of the door 108.

As noted earlier, the door 10S may be deformed or bowed inwardly during closing, due to the application of an excessive closing force to an unsupported portion of the door. Unless the magnet 114 is restrained against inward movement beyond its position of FIGURE 16, wherein the magnet is disposed for proper latching engage-ment with the armature 10.6 when the door 108 is closed, this inward deformation of bowing of the door will result in inward movement of the magnet beyond its position of FIGURE 16. In this case, the armatureand magnet will not enter into proper latching engagement during subsequent closing of the door by the application of a normal closing force to the door. In the latch 100, this possibility of inward movement of the magnet 114 into the magnet housing 110, beyond the proper latching position'of the magnet, due to the application of an excessive closing force to the door 108 after initial installation of the latch is avoided by bending the lower arm 128 of the -magnet positioning clip 124 about the outer edge of the magnet housing, as shown in FIGURE 16. When the lower clip leg is thus bent, the clip 124 is effective to restrain the magnet 114 against both inward and outward movement relative to the magnet housing 110. The possibility of the magnet being -forced into its housing 110, beyond its proper latching position of FIGURE 16, therefore, is avoided.

As noted earlier, the magnet 114 is capable of limited edge wise pivotal movement relative to its positioning clip 124 and its housing 110. This providesthe magnet with a swivel action which permits the outer end of the magnet to align itself fiat against the confronting face of the armature 106, as is desirable for an optimum magnetic latching action. Preferably, the outer edge of the lower side wall of the magnet housing 110 is notched at 138 to receive the outer bent end of the lower leg 128 of the magnet positioning clip 124 for the purpose of restraining the clip against swivelV movement with the magnet which might result in improper engagement of the upper clip leg 126 with the housing serrations 112.

As in the earlier forms of the invention, lthe magnet housing 110 may be secured to its respective supporting member 104 of theclosure structure in any convenient way. In the drawings, for example, the upper wall of the housing 110 is coated with a contact adhesive ,140 for securing the housing to its supporting member 104. v

The modified latch 200 illustrated in FIGURES 18 through 20 comprises primary and

secondary latch parts

202 and 204, respectively, Latch part 202 includes a hollow rectangular housing 206 of non-magnetically permeable material. Extending through the lower wall of this housing is a longitudinal slot 208. A longitudinal row of spaced serrations or indentations 209 are formed in the under sur-face of the lower housing wall. Slidably disposed within and movable longitudinally of the housing 206 is a laminated magnetic structure, or magnet 210. Magnet 210 is substantially identical to the magnet 114 in FIGURES l through 17 except that the bearing journals 122 of the latter magnet are eliminated and replaced by aligned journal bores 212 which extend coaxially through the center magnetic plate 214 and outer magnetically permeable plates 216 of the magnet. As shown in FIGURES 18 and 19, the overall thickness of the magnet 210 is just slightly less than the corresponding internal dimension of the magnet housing 206. The width of the magnet 210, measured between the longitudinal edges of the outer plates 216 of the magnet, is somewhat less than the corresponding internal dimension of the magnet housing, whereby the magnet is capable of edgewise pivotal movement in the housing.

Rotatably fitted within the aligned journal bores 212 in the magnet 210 is a journal pin 218 having a lower end or extension 220 of reduced diameter defining on the pin an axially presented annular shoulder 222. The axial dimension of the journal pin 218, measured between the upper end face of the pin and the shoulder 222, is substantially equal to the overall thickness of the magnet 210. The axial dimension of the journal pin extension 220 is just slightly less than the thickness of the lower wall of the magnet housing 206. The diameter of the pin extension is slightly less than the width of the housing slot 208. Journalpin 218 is internally bored and threaded to receive a lock screw 224. Mounted on the threaded shank of the lock screw 224 is a spring clip 226.

When the latch art 202 is assembled, the extension 220 of the journal pin 218 extends through the slot 208 in the magnet housing 206. The lock screw 224 is threaded in the lower end of the pin, and the spring clip 226 is disposed below the lower wall of the magnet housing. The forward end of this clip is bent, as shown, to define a resilient detent which is engageable with the housing serrations 209 to restrain the magnet 210 against outward movement relative to the housing.

At this point, it is evident that when the lock screw 224 is loosened slightly, the magnet 210 is permitted to move inwardly relative to the magnet housing 206 but is restrained against outward movement relative to the housing by engagement of the spring clip 226 with the housing serrations 209. When the lock screw 224 is tightened, the journal pin shoulder 222 is clamped tightly against the lower wall of the magnet housing 206, at opposite sides of the housing slot 208, thereby to positively secure the magnet 210 against both inward and outward movement relative to the housing. It is signicant to note here that the magnet 210 is capable of limited edge wise movement in the housing when the lock screw 224 is loosened, as well as when the screw is tightened to secure the magnet against longitudinal movement.

The secondary latch part 204 comprises a magnetically permeable armature plate 228 having a mounting surface bearing a contact adhesive 230.

The modified latch 200 is installed in much the same Way as the latch 100, described earlier. Accordingly, there is no need to explain, in detail, the installation procedure of the latch 200. lt should be noted, however, that when installingV the latch, the lock screw 224 is loosened to permit the magnet 210 to be moved longitudinally to its proper latching position within the magnet housing 206 by the thrust of the armature 204 against the magnet occasioned by closing of the door 232 of the closure structure on which the latch is mounted. Engagement of the spring clip 226 with the housing serrations 209 restrains the magnet against outward movement relative to t-he housing during subsequent opening of the door. After installation of the latch, the lock screw 224 may be tightened to positively secure the magnet against inward movement relative to the housing for the reason discussed earlier in connection with the latch illustrated in FIG- URES 15 through 17. The pivotal mounting of the magnet 210 provides the magnet with a swivel action which permits the outer end of the magnet to align itself fiat against the `armature 204.

It will -be understood that latches according to the present invention may employ attachment or gripping means on the secondary latch part, or armature, other than the illustrated contact adhesive. For example, either the armatures or t-he magnet housings may be provided with sharp prongs or teeth which may be driven into the closure or the support for the purpose of ataching these members.

While the invention has been disclosed herein primarily in connection with magnetic latches, it is apparent that the invention is not limited in usefulness to magnetic latches.

Those versed in the art will appreciate that the present invention achieves the objects and realizes the advantages hereinbefore mentioned.

Although specific embodiments of the present invention have been illustrated and described herein, it will be understood that the same are merely exemplary of presently preferred embodiments capable of attaining the objects and advantages hereinbefore mentioned, and that the invention is not limited thereto; variations will be readily apparent to those versed in the art, and the invention is entitled to the broadest interpretation within the terms of the appended claims.

The inventors claim:

1. A latch for releasably joining two members comprising: first and second latch parts disposed in mutual contact with said parts in latching relation, coacting latching means on said parts, respectively, for releasably joining said parts in latching relation, means for securing one of said parts to one of said members in such manner that relative movement of said members toward one another is effective to establish contact between the other part and the other member, and gripping means on said other part for producing between said other part and said other member upon said contact thereof an attachment which restrains said other part :and said other member against separation under the action of a force exceeding the force required to separate said coacting latching means.

2. A latch according to claim 1 wherein: said gripping means comprises a contact adhesive.

3. A magnetic latch for releasably joining two members, comprising: a first latch part including a permanent magnet, a second latch part including a magnetically permeable armatu-re disposed in abutting magnetic latching engagement with said first part, said parts being releasably joined by magnetic attraction, means for securing one of said parts to one of said members in such manner that relative movement of said members toward one another is effective to establish contact between the other part and the other member, and gripping means on said other part for producing between said other part and said other member upon said contact thereof an attachment which restrains said other part and said said other member against separation under the action of a force exceeding the force required to separate said magnet and armature.

4. A latch according to claim 3, wherein: said one part comprises said magnet and said other part comprises said armature.

5. A latch according to claim 1 wherein: said means for securing said one part to said one member comprises a contact adhesive.

6. A magnetic latch for releasably joining two members, comprising: a first latch part including a housing and a first magnetically permeable element movable in and extending at one end from said housing, a second latch 1 1 part including a second magnetically permeable element, one of said elements comprising a permanent magnet and the other element comprising a magnetically permeable armature, said elements being disposed in magnetic latching engagement, means for securing one of said parts to one of said members in such manner that movement of said members toward one another is effective to establish contactv between the other part and the other member, means for securing said other part to said other member, and coacting restraining means on said housing and said first element for restraining the latter element against movement relative to said housing in the direction of said second element while permitting movement of said first element relative to said housing in the opposite direction.

7. A magnetic latch according to claim6 including: additional restraining means coacting between said housing and said first element for selectively restraining said first element against movement in said opposite direction relative to said housing.

8. A magnetic latch according to claim 6 wherein: said first element comprises said magnet and said second element comprises said armature.

9. A magnetic latch according to claim 6 wherein: said gripping means comprises a contact adhesive.

10. A magnetic latch according to claim 6 wherein: said restraining means comprises ratcheting means.

11. A magnetic latch according to claim 6 wherein: said restraining means comprises serrations on said first element and resilient detent means on said housing disposed in ratcheting engagement with said serrations.

12. A magnetic latch according to claim 6 wherein: said restraining means comprises serrations on said housing and resilient detent means operatively connected to said first element and disposed in ratcheting engagement with said serrations.

13. A magnetic latch according to claim 6 wherein: said restraining means comprises frictional restraining means.

14. A magnetic latch according to claim 6 wherein: said first element is cylindrical in transverse cross-section and fits slidably within a bore in said housing, and said restraining means comprises a friction washer secured to said housing and frictionally receiving said first element.

15. A magnetic latch according to Vclaim 6 wherein: said first element and said housing have confronting surfaces extending in the general direction of relative movement of said first element in said housing, said confronting surfaces inclining toward one another in the direction of the inner end of said first element, and said restraining means comprises wedging means disposed between said confronting surfaces, respectively, and wedgeable therebetween upon outward movement of said first element relative to said housing.

16. A magnetic latch according to claim 3, wherein: said magnet and armature have engaging surfaces, one of said surfaces being rounded and the other surface having an arcuate recess receiving said rounded surface.

17. A magnetic latch according to claim 6, wherein: said first element is pivotally movable relative to said housing in a direction transverse to the direction of relative movement of said first element in said housing.

18. A magnetic latch according to claim 6, wherein: said means for securing said other latch part to said other member comprises gripping means for producing between said other part and said other member upon said contact thereof an attachment which restrains said other part and said other member against separation under the action of a force exceeding the force required to separate said armature and magnet.

19. A magnetic latch for releasably joining two members, comprising: a first latch part including a hollow generally rectangular housing and a generally flat first magnetically permeable element longitudinally movable in and extending beyond one end of said housing, a second latch part including a second magnetically permeable 12 Y .s element, one of ,said elements comprisinga permanent magnet and the other element comprisingva magnetically permeable armature, said elements being disposed in magnetic latching engagement, means 4for, securing o neof said parts to one of said members in such l.manner that movement of said members toward one another, is effective to establish contact between the other part and the other member, means for securing said other. part toV said other member, a resilient generally U-,shaped .positioning clip straddling the inner end of said first element-,including legs extending between the opposite sides of said firstelement and the confronting side walls of said housing, means connecting said first element .tosaid clip legs, one of said clip legsbeing bent outwardly toward the adjacent housing side wall to form a resilient detent .enfgageable with the latter side wall to restrain said first'ele'- ment against longitudinal movement relativeto :said housing in the direction of said one endof said :housing while permitting movement of Said first element relative to said housing in the opposite direction, and the other clip leg extending beyond one end of saidhousing and being adapted to be bent around theadjacent edge of the adjacent housing side wall to restrain said first `element against movement relative to said housing said' oppo site direction.

20. A magnetic latch according to claim 19, wherein: the transverse edge wise dimension of said firstA element is substantially less than the correspondinginternal dimension of said housing, and said connecting means between said first element and said clip comprises journal means, whereby said first elementis pivotally movable in the edge wise direction relative to said housing. j

21. A magnetic latch for releasably joining two members, comprising: a first latch part including a hollow generally rectangular housing and a generally'flat first magnetically permeable element longitudinally movable in and extending beyond one end of said housing, aseoond latch part including a second magnetically permeable element, one of said elements comprisingl a permanent magnet and the other element comprising a magnetically permeable armature, said elements being disposed niagnetic latching engagement, means for securing one of said parts to one of said members in such manner that movement of said members toward one .another is effective to establish seating contact between the other part and the other member, a pin extending throughsaid r's't element normal to the plane thereof, said pin having a rduced diameter end extending through a longitudinal slot in the adjacent side wall of said housing and an axially presented shoulder engaging said sidewall at opposite side of said slot, the lock screw threaded in said p infor urging said shoulder into clamping engagementwith said side wall, thereby to restrain first-element against longitudinalmovement relative to saidvhousing, anda resilient clip mounted on said lock screw externally of said housing and engaging said housing side wallto restrain said first element against longitudinal movementrelativev to said housing in the direction of said one end -of said housing. v

22. A magnetic latch according to claim21 wherein: the transverse edgewise dimension of said first element is substantially less than the corresponding internal dimension of said housing, and said pin is rotatably fitted in said first element, whereby said first element is adapted lfor edgewise pivotal movement relative to saidv housing. ,r

23. A magnetic latch comprising: a firstflatch'part in.- cluding a housing, a magnet movablein said housing and extending beyond one end of said housing, means acting between said magnet and housing'for restrainingsaid magnet against movement relative to said housingin the direction of one end of said housing while permitting movement of said magnet in the opposite direction 'rela-f tive to said housing, a second latch part including a mag'- netically permeable armature disposed in magnetic latching engagement with the outer end of said magnet, said housing and armature having mounting surfaces, respectively, and a contact adhesive applied to each of said mounting surfaces.

24. A magnetic latch for releasably joining two members, comprising: a rst latch part including -a housing and a first magnetically permeable element movable in said housing, a second latch part including a second magnetically permeable element, one of said elements comprising a permanent magnet and the other element comprising a magnetically permeable armature, said elements being disposed in magnetic latching engagement, means for securing one of said parts toone of said members in such manner that movement of said members toward one another is effective to establish contact between the other part and the other member, means for securing said other part to said other member, and coacting restraining means on said housing and said rst element for restraining the latter element against movement relative to said housing in the direction of said second element while permitting movement ot said rst element relative to said housing in the opposite direction, thereby to permit self-adjusting movement of said first element relative to said housing in said opposite direction during movement of said members toward one another to establish initial contact between said other part and said other member.

25. The method of installing a latch including first and second latch parts disposed in mutual latching engagement which comprises the steps of: securing one of said latch parts to one member of a closure structure including movable closure member and a supporting membertherefor in such manner that movement of said closure member to its closed position is effective to establish initial contact between said other part and said other member and thereafter to move said one part in self-adjusting movement in a given direction relative to said one member, moving said closure member to said closed position thereof to establish pressure contact between said other part and'said other member and Vsimultaneously move said one part in said self-adjusting movement relative to said one member to a final position of adjustment, effecting mutual joinder of said other part and said other member in response to said pressure contact thereof in a manner such as to create between said latter part and member a joint which requires a greater force to separate than the force normally required to separate said latch parts, and restraining said one part against relative movement from said final position of adjustment relative to said one member during subsequent movement of said closure member from said closed position.

References Cited UNITED STATES PATENTS 2,855,242 10/1958 Holmes 296-97 2,935,353 5/1960 Loeb 292-251.5 2,990,210 6/1961 Fremstod 292-251.5 3,023,991 3/ 1962 Fisher 248-205 3,169,743 2/ 1965 Page 248-206 3,174,786 3/1965 Wilson 292-251.5 3,287,051 11/ 1966 Anderson 292-251.5 3,260,788 7/1966 Stetson 292-251.5 X

MARVIN A. CHAMPION, Primary Examiner.

EDWARD J. MCCARTHY, Assistant Examiner.

U.S. Cl. X.R. 29-404