Security seal

Abstract: A security seal (10) for use with an electrical socket (14) to provide evidence of tampering with an electrical plug (18) received in the socket. The security seal includes a back plate (12) having a rearwardly facing rear surface fixable relative to the electrical socket and a forwardly facing front surface. The back plate has at least one opening which extends between the front and rear surfaces, and which is alignable with pin receptacles of the socket. A cover (16) is detachably mounted to the back plate (12), and defines a cavity for covering an electrical plug (18) having pins extending through the back plate openings and received in the socket pin receptacles. Detaching the cover (16) from the back plate (12) to gain access to the plug (18) deforms the cover or back plate to provide evidence of tampering with the electrical plug.

Description: BACKGROUND OF THE INVENTION The field of invention is protective security seals for electrical plugs plugged into electrical sockets, and more particularly to security seals which protect electrical plugs plugged into sockets and provide evidence of tampering with the plug. Certain electrical devices, such as refrigerators in laboratories, medical devices, computers, communication and manufacturing systems, must be continuously connected to a source of electrical power to avert life threatening events, loss of sensitive data or material, or prevent expensive restart. Electrical power to many of these electrical devices is provided through an electrical plug plugged into an electrical socket. The plug can be inadvertently pulled from the socket to disconnect the power, or can be intentionally disconnected from the electrical source. Even a temporary loss of electrical power can result in an undesirable event which may not be detectable for a period of time. For example, loss of refrigeration for a laboratory sample may alter the sample. The alteration of the sample could be the result of a number of events. Therefore, without evidence of a potential loss of power to the refrigeration equipment, the cause of the sample alteration could remain undetermined. Security covers designed to protect children from electrical shock are known. However, a plug protected by these devices is easily accessed by an adult without evidence that security of the plug has been breached. Therefore, a need exists for a security seal which provides evidence of tampering with the plug. US-A-4932874 discloses a security seal in accordance with the features recited in the precharacterizing portion of claim 1. A cover in form of an elongated housing sleeve has a pair of passages. A flexible tubular member is mounted in a first of these passages housing a radio frequency cable the electrical plug or cable connector of which is to be attached to a socket of an electrical equipment. A lip of the cover forms a substantially planar surface surrounding the opening of the first passage adjacent to the electrical equipment. Furthermore, specially actuable locking means are mounted in a second one of the above passages. The locking means comprise a threaded member for threaded engagement with threaded means on the electrical equipment. The lip together with this threaded member provide a tight fit between the cover or housing sleeve and the electrical equipment. This prevents prying and tampering with the cover since there is no room for insertion of a tool therebetween and any attempted tampering would damage or destroy the equipment. The lock may be disengaged by means of a key. In the device disclosed in GB-A-2278245 removal of a cover can be achieved without a key solely by squeezing flexible arms towards each other which can be done easily and rapidly. In this manner a snap-fit between the cover and a supporting back plate is disengaged. The back plate has projections which cooperate with said flexible arms for engagement of cover and plate. The cover comprises lugs which serve to shield an electrical switch provided adjacent the socket and plug pin holes in the support plate. It is a general objective of the present invention to provide a security seal which provides evidence of tampering by a seal which permanently deforms when a user gains access to the protected plug. This objective is solved by the subject matter of claim 1. Advantageous further developments are defined in the subclaims. The invention provide a security seal for use with an electrical socket to provide evidence of tampering with an electrical plug received in the socket, said security seal comprising: a back plate having a rearwardly facing rear surface fixable relative to the electrical socket and a forwardly facing front surface and having at least one opening extending between said front and rear surfaces and being alignable with pin receptacles of the socket; and a cover detachably mounted to said back plate and defining a cavity for covering an electrical plug having pins extending through said back plate openings and received in the socket pin receptacles, wherein detaching said cover from said back plate permanently deform at least one of said cover and said back plate characterized in that said cover is detachably mounted to said back plate with a latch fixed to one of said back plate and said cover and a catch fixed to the other of said back plate and said cover and engageable with said latch, wherein disengagement of said latch from said catch deforms said cover to provide evidence of tampering with the electrical plug. Preferably, the cover is deformed by tearing. The security seal inhibits access to a plug plugged into an electrical socket by a cover which encloses the plug plugged into the socket. The foregoing and other objects and advantages of the invention will appear from the following description. In the description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown by way of illustration a preferred embodiment of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a security seal incorporating the present invention; Fig. 2 is an exploded perspective view of the security seal of Fig. 1; Fig. 3 is a bottom perspective view of the security seal of Fig. 1; Fig. 4 is a perspective cut away view of the security seal of Fig. 1; Fig. 5 is a cross sectional view of the security seal of Fig. 1; Fig. 5A is a detailed cutaway view of the security seal of Fig. 1; Fig. 6 is a perspective view of another security seal incorporating the present invention; and Fig. 7 is an exploded perspective view of the security seal of Fig. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to Figs. 1-5, a security seal 10 includes a molded back plate 12 which is fixed over an electrical socket 14, and a molded cover 16 which is detachably mounted to the back plate 12. The cover 16 encloses a plug 18 having electrical conductor pins 20 inserted into electrical socket pin receptacles 30. The cover 16 prevents easy access to the plug 18, and reduces the risk of inadvertently disconnecting an electrical device from a source of electrical energy by pulling the plug 18 from the socket 14. Detaching the cover 16 from the back plate 12 to gain access to the plug 18 permanently deforms the cover 16 or back plate 12, such as by tearing or breaking the cover 16 or breaking the back plate 12 to provide evidence of tampering. The back plate 12 is a substantially flat plate having a rearwardly facing rear surface 24 which abuts the socket 14 and a forwardly facing front surface 26 which is enclosed by the cover 16. Apertures 28 formed in the back plate 12 are aligned with socket pin receptacles 30 for insertion of the plug conductor pins 20 into the electrical socket pin receptacles 30. Although a separate aperture aligned with each pin receptacle 30 is disclosed, a single aperture which allows insertion of the plug conductor pins 20 into the socket pin receptacles 30 can be provided without departing from the scope of the present invention. An adhesive applied to the back plate rear surface 24 adhesively attaches the back plate 12 to the socket 14. Of course, other methods for fixing the back plate 12 to the socket 14 can be used, such as screws, and the like, without departing from the scope of the present invention. Feet 32 extending substantially perpendicular from the back plate 12 below the holes 34 support the cover 16 mounted to the back plate 12. Holes 34 formed in the feet 32 engage downwardly projecting posts 36 formed in the cover 16 to prevent slidable movement of the cover 16 relative to the feet 32, and positions the cover 16 over the plug 18 plugged into the socket 14. Locating structure 38 and holes 40 can be formed in the back plate front surface 26 to engage the cover 16 and properly position the cover 16 relative to the back plate 12. Referring to Figs 2-5, a resilient shelf 42 extending substantially perpendicular from the back plate front surface 26 above the apertures 28 includes a downwardly opening catch 44. The catch 44 engages an upwardly projecting latch 43 formed in the cover 16 to lock the cover 16 to the back plate 12 over the plug 18. Of course, the catch 44 can be formed as an integral part of the cover 16 and the latch 43 as an integral part of the back plate 12 without departing from the scope of the present invention. The cover 16 defines a rearwardly opening primary cavity 45 which encloses the plug 18 having electrical conductor pins 20 inserted through the back plate apertures 28 into the socket pin receptacles 30. The primary cavity 45 is defined by a bottom wall 46, top wall 48, and side walls 50 joined by a front wall 52 to enclose the plug 18 plugged into the socket 14. An opening 54 formed in the cover bottom wall 46 provides a passage for a cord connected to the plug 18. A depression 56 formed in the front wall 52 provides a location for labeling the cover 16, such as to designate the electrical device electrically connected to the plug 18 plugged into the socket 14. The cover 16 is vertically supported by the feet 32 which engage the cover bottom wall 46. The downwardly projecting posts 36 extending from the cover bottom wall 46 are received in the feet holes 34. Although pins engaging holes in feet are disclosed herein for positioning and supporting the cover, other methods, such as disclosed in the alternative embodiment shown in Figs. 6 and 7, can be used without departing from the scope of the present invention. Switch protectors 58 formed as an integral part of the side walls 50 define rearwardly facing secondary cavities adjacent the primary cavity 45 to cover an electrical control device 60, such as a switch, button, and the like, adjacent the socket pin receptacles 30. The switch protectors 58 cover the electrical control device 60 to prevent access to, and thus, operation of the control device 60. The upwardly projecting latch 43 formed in the cover top wall 48 engages the catch 44 formed in the base plate shelf 42. The latch 43 is straddled by a pair of legs 62 supporting a pull tab 64 having a pull ring 66 formed on its distal end. The legs 62 define an opening in the pull tab 64 which receives the shelf 42 when the cover 16 is mounted on the back plate 12. Preferably, when the cover 16 is engaged with the back plate 12, the tab 64 abuts the back plate 12 to prevent rearwardly movement of the tab 64 and disengagement of the latch 43 from the catch 44 by pivoting the tab 64 rearwardly. The cover top wall 48 and shelf 42 are resilient members which allow engagement of the latch 43 with the catch 44 without permanently deforming, such as tearing or breaking, the cover 16 or shelf 42. Disengaging the latch 43 from the catch 44, by grasping the pull ring 66 and pulling the tab 64 forwardly away from the back plate 12, tears the cover top wall 48 and pulls the latch 43 from the catch 44. Tearing the cover top wall 48 permanently deforms the cover 16 to provide evidence of tampering with the cover 16, and thus the plug 18. In the embodiment shown herein, the cover top wall 48 is scored around the tab 64 to facilitate tearing of the cover top wall 48 when disengaging the latch 43 from the catch 44. Preferably, as shown in Fig. 5A, the latch 43 is supported at each end by break away supports 47 which break when the cover 16 is detached from the back plate 12 to deform the cover 16 and prevent reattachment of the cover 16 to the back plate 12. The supports 47 support the latch 43 above the cover top wall 48 and define a gap 49 between the cover top wall 48 and latch 43. The latch 43 supported by the supports 47 can be provided in addition to, or independent of the scoring without departing from the scope of the present invention. In use, the back plate 12 is adhesively fixed to the socket 14, such that the back plate apertures 28 are aligned with the socket pin receptacles 30. The plug 18 having a downwardly extending cord is plugged into the socket 14 by inserting the plug conductor pins 20 through the back plate apertures 28 and into the socket pin receptacles 30. The cover 16 is positioned over the plug 18 and the downwardly projecting locating posts 36 are slipped into the alignment holes 34 formed in the feet 32. The cover latch 43 is then snapped into engagement with the back plate catch 44 by pivoting the cover 16 rearwardly until the latch 43 engages the catch 44. To gain access to the plug 18, a user grasps the pull ring 66 and tears the cover top wall 48 away from the back plate 12 and side walls 50 to disengage the latch 43 from the catch 44. Once the latch 43 is disengaged from the catch 44, the feet locating posts 36 are slipped out of the alignment holes 34 in the feet 32 to expose the plug 18. Once the cover top wall 48 has been torn away, it cannot be reused and provides evidence that plug security has been breached. The adhesively mounted back plate 12 can be removed by prying the back plate 12 away from the socket 14. In an alternative embodiment shown in Figs. 6 and 7, a security seal 100 includes a molded back plate 102 which is fixed over an electrical socket 104, and a molded cover 106 is detachably mounted to the back plate 102. As in the first embodiment, the cover 106 encloses a plug 108 having conductor pins 109 plugged into the socket 104 through apertures 110 formed in the back plate 102 and aligned with socket pin receptacles 112. Locating structure 117 formed in the back plate front surface 116 engage the cover 106 and properly position the cover 106 relative to the back plate 102 over the plug 108. The locating structure 117 includes ridges 118 which extend forwardly from the back plate front surface 116 to engage an inner surface of the cover 106, and locating pins 120 which extend forwardly from the back plate front surface 116 and are received in rearwardly facing locating cavities formed in the cover 106. A switch protector 122 is formed as an integral part of the back plate 102, and defines a rearwardly facing cavity to cover an electrical control device, such as a switch, button, and the like, adjacent the socket 104. The switch protector 122 covers the electrical control device adjacent the socket pin receptacles 112 when the back plate 102 is fixed relative to the socket 104 to prevent access to, and thus, operation of the control device. The cover 106 includes a bottom wall 124, top wall 126, and side walls 128 joined by a front wall 131 which defines a rearwardly opening primary cavity which encloses the plug 108. The cover 106 is supported adjacent to the back plate 102 by the locating structure 117 extending from the back plate 102. As in the first embodiment, an upwardly projecting latch 133 formed in the cover top wall 126 engages a downwardly opening catch formed in a shelf 130 extending from the back plate 102. A pull tab 132 is formed as an integral part of the cover top wall 126, and has a pull ring 134 formed on its distal end. The cover top wall 126 and shelf 130 are resilient members which allow engagement of the latch 133 with the catch without permanently deforming the cover 106 or shelf 130. Disengaging the latch 133 from the catch, by grasping the pull ring 134 and pulling the tab 132 forwardly away from the back plate 102, tears the cover top wall 126 and pulls the latch 133 from the catch. Tearing the cover top wall 126, permanently deforms the cover 106 to provide evidence of tampering with the cover 106, and thus the plug 108. In use, as in the first embodiment, the back plate 102 is fixed to the socket 104, such that the back plate apertures 110 are aligned with the socket pin receptacles 112. The plug 108 having a downwardly extending cord is plugged into the socket 104 by inserting the plug conductor pins 109 through the back plate apertures 110 and into the socket pin receptacles 112. The locating structure 117 positions the cover 106 over the back plate 102 and plug 108, and the latch 133 is snapped into engagement with the catch by urging the cover 106 against the back plate 102 to lock the cover 106 over the plug 108. To gain access to the plug 108, a user grasps the pull ring 134 and tears the cover top wall 126 away from the side wall 128 to disengage the latch 133 from the catch. Once the latch 133 is disengaged from the catch, the cover 106 is pulled away from the back plate 102. While there has been shown and described what are at present considered the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention defined by the appended claims. For example, structure, such as switch protectors, for protecting an electrical control device adjacent the socket pin receptacles can be omitted without departing from the scope of the present invention. Therefore, various alternatives and embodiments are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.

Claims: A security seal (10; 100) for use with an electrical socket (14, 104) to provide evidence of tampering with an electrical plug (18; 108) received in the socket, said security seal comprising: a back plate (12; 102) having a rearwardly facing rear surface (24) fixable relative to the electrical socket (14; 104) and a forwardly facing front surface (26; 116) and having at least one opening (28; 110) extending between said front (26; 116) and rear surfaces (24) and being alignable with pin receptacles(30; 112) of the socket; and a cover (16; 106) detachably mounted to said back plate (12; 102) and defining a cavity (45) for covering an electrical plug (18; 108) having pins (20; 109) extending through said at least one opening (28; 110) and received in the socket pin receptacles (30; 112), wherein detaching said cover (16; 106) from said back plate (12; 102) permanently deform at least one of said cover (16; 106) and said back plate (12; 102) characterized in that : said cover (16; 106) is detachably mounted to said back plate (12; 102) with a latch (43; 133) fixed to one of said back plate (12) and said cover (16) and a catch (44) fixed to the other of said back plate (12, 102) and said cover (16; 106) and engageable with said latch (43), wherein disengagement of said latch (43; 133) from said catch (44) deforms said cover (16; 106) to provide evidence of tampering with the electrical plug (18; 108). The security seal of claim 1, in which a pull tab (64; 132) is formed as an integral part of said cover (16;106), pulling said tab tears said cover to disengage said catch (44) from said latch (43; 130) and renders said cover (16; 106) unusable with said back plate (12; 102). The security seal of claim 1, in which said latch (43;130) is supported at each end by break away supports (47) which break when said cover (16;106) is detached from said back plate (12;102). The security seal of claim 3, in which a ring (66; 134) is formed on a distal end of said pull tab (64;132) for grasping by a user. The security seal of claim 1, in which said back plate (102) includes a rearwardly opening cavity formed in said back surface for covering an electrical control device adjacent to the pin receptacles (112). The security seal of claim 1, in which locating pins (120) extend forwardly from said back plate (102) for engagement with said cover (106) to position said cover relative to said back plate. The security seal of claim 1, in which feet (32) extend forwardly from said back plate (12), and said feet vertically support said cover (16) detachably mounted to said back plate (12). The security seal of claim 7, including locating holes (34) formed in said feet (32) for engagement with locating pins (36) extending from said cover (16). The security seal of claim 1, in which said back plate (12) has locating holes (34) formed therein for receiving locating posts (36) extending from said cover (16) to position said cover (16) relative to said back plate (12). The security seal of claim 1, in which said cover (16) includes another cavity which covers an electrical control device (60) adjacent to the pin receptacles (30). The security seal of claim 1, in which adhesive is applied to said back plate back surface (24) to fix said back plate (12) relative to the socket (14). The security plug of claim 1, in which a depression (56) is formed in said cover (16) for affixing a label.

Inventors: BOUND KEITH R, BOUND, KEITH R.
Applicants: TRICOR DIRECT INC, TRICOR DIRECT, INC.
Application year: 2000
Main classification: H01R13
IPC codes: G08B13, H01R13