Apparatus for controlling use of electrically powered equipment

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APPARATUS FOR CONTROLLING USE OF
ELECTRICALLY POWERED EQUIPMENT

BACKGROUND

1. Field of Invention

This invention relates to electric switches in general and particularly to a lockable structure enclosing an electric switch.

2. Description of Prior Art
With the widespread and ever-increasing use of all

types of electrical equipment, there has developed a need for an apparatus which can control the unauthorized use of this equipment. The need for this type of 15 apparatus has developed as a result of the increasing interest in and emphasis on security and safety, as related to the operation of electrical equipment.

In the field of power tools which are used in the home and in schools, there is a need to restrict the use of these 20 devices to authorized users and prevent use thereof by small children in the home or students who have not received the appropriate training. There is a similar need to limit the use of certain electrical equipment such as grinders, food processors, and slicers. Devices cur- 25 rently on the market such as outlet covers provide little safety because they can be easily figured out by curious youth.

In the home, it is often necessary to control the use of television receivers and video tape recorders by chil- 30 dren. This need is related to a desire to limit the extent of television viewing by children and to restrict this use to programming which is considered appropriate.

In commercial offices, there is often a need to restrict the use of office copiers, typewriters, and other electrical equipment and to prevent the use of this equipment by unauthorized persons. This requirement often occurs when an office must remain open for purposes of cleaning or maintenance after the end of the normal business day when the authorized personnel are no longer present.

Another reason for the development of a means of limiting the operation of equipment to authorized users has been the widespread application of computers to 4J every phase of commercial and industrial activity. This has resulted in a situation where an unauthorized user can, either unintentionally or intentionally as a result of malice, do a substantial amount of damage. This damage can result from both the entry into computer networks 5Q and the destruction or tampering with the equipment or data, as well as the obtaining of sensitive information stored in these files.

In addition, in laboratories where certain electrically operated sensitive test equipment is located, there is a 55 similar need to restrict access to such equipment.

Some newer types of electrical equipment include a keylock feature in which a removable key is used to activate a switch which applies electrical power to the equipment. This feature meets the need for a means of 60 limiting the operation of the equipment to authorized users. However, this feature is found only in relatively expensive types of equipment and relies on a key that could be easily lost or require the creation of a large number of copies to grant access to all authorized users. 65 Retrofitting this feature on existing equipment is quite costly and in most cases extremely difficult or impossible. Thus, there is compelling need for a practical and

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economical means for controlling the use of electrical equipment.

Inventors have created several types of security devices to control access to electrical equipment. Their approaches to this problem are undesirable because they do not combine simplicity, ease of manufacture, and programmable, keyless operation in a single design. Simplicity of installation and operation as well as ease of manufacture are important if the manufacturer wants to sell a quality product to the widest range of users at the lowest possible price. Keyless operation is important because it removes the need to carry around a set of keys to run each piece of equipment the user requires access to and avoids the problems of searching for and eventually replacing lost keys. Lock programmability is important because it allows the user to personalize combinations to numbers that are easy to remember. It also provides the user the option to standardize combinations to a single number that can be applied to all the equipment the user operates. These characteristics help make the device more marketable to the general public and industry.

U.S. Pat. No. 2,629,029 to Raphael (1953) employs a keyless device but denies the user the ability to program the combination. This design also ignores available off-the-shelf components as well as opens the user to a potential shock should the power switch lack the proper insulation necessary to separate the switch from the lock to which it is directly connected. U.S. Pat. No. 3,774,049 to Coleman (1973), also a keyless device, focuses mainly on automobile applications. This design also relies on a pre-assigned combination and requires many custom components resulting in higher manufacturing costs.

U.S. Pat. Nos. 3,524,029 to Laff (1970), 4,063,110 to Glick (1977), 4,479,688 to Jennings (1984), 4,482,789 to McVey (1984), and 4,647,735 to Sicher (1987) require keys to engage the flow of electricity from the electrical wall outlet to the electrical connector receptacle. U.S. Pat. No. 5,061,199 to McClead (1991) requires a total of three keys to regulate its' operation, increasing the expense and complexity of implementing this electrical apparatus. This apparatus also requires electrical appliances to employ an electrical connector with holes in the blades to allow insertion of a locking rod. With this limitation, connector designs such as the pole type employed abroad are excluded from being used in this device. U.S. Pat. No. 3,247,337 to Wiegel (1963), an invention focusing on controlling the flow of electricity at the circuit breaker level, requires only a single key but does not provide a means to secure electrical appliances to a source of power. U.S. Pat. No. 3,524,029 to Laff (1970) includes a permanently fastened lid that denies the removal of the electrical connector from the device, preventing the user from removing or replacing the protected appliance. U.S. Pat. No. 5,193,665 to Jankow (1993) requires a key to engage the flow of electricity from the electrical wall outlet to the electrical appliance cord. This design additionally restricts the use of this device to a single appliance because it is directly part of the appliance cord. The last eight patents pose a potential safety risk because they lack the ability to stop the flow of electricity through the device without first inserting a key into the lock. This safety risk makes the devices undesirable for areas where children are present or where a "panic button" is required. 3

OBJECTS AND ADVANTAGES

Accordingly, several objects and advantages of the present invention are:

(a) to provide an electrical apparatus that allows 5 electrical equipment to be rendered inoperative and incapable of use by unauthorized personnel;

(b) to provide an electrical apparatus which can be manufactured using a variety of lock designs;

(c) to provide an electrical apparatus which can em- 10 ploy a keyless operation to connect an electrically operated device to a source of power;

(d) to provide an electrical apparatus which employs a securing operation that allows only authorized users to remove electrical power connectors from 15 its receptacles;

(e) to provide an electrical apparatus which can be easily installed on existing electrically operated devices, which could include the direct attachment

to an existing wall outlet, without a need for modi- 20 fication of these devices in any way;

(f) to provide an electrical apparatus which can be easily operated in concert with existing electrically operated devices without any specialized knowledge of electricity or the devices being used; 25

(g) to provide an electrical apparatus that emphasizes safety in its design, allowing the flow of electricity to be stopped without requiring operation of the locking features of the electrical apparatus;

(h) to provide an electrical apparatus which is mainly 30 comprised of off-the-shelf component parts which are readily available and economical to manufacture, resulting in a relatively low unit cost; and

(i) to provide an electrical apparatus with a minimal part count for economy and ease of manufacture. 35

The foregoing and additional objects and other important advantages of the present electrical apparatus may be more fully understood from the ensuing description in conjunction with the accompanying drawings, which latter although showing but one embodiment of 40 the electrical apparatus, are by no means intended in a restricting sense, since the apparatus may have to be altered in its adaptation for different purposes, such as the employment of the apparatus with a power cord so the apparatus can be operated by users when the appa- 45 ratus is connected to wall outlets located behind large objects such as refrigerators. Many other uses are possible after performing a thorough review of the ensuing description in conjunction with the accompanying drawings. 50

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided an apparatus for controlling use of electrically powered equipment that allows electrically operated 55 devices to be rendered inoperative and incapable of use by unauthorized personnel. The electrical apparatus consists of an enclosure which is proportioned to accept the electrical power connectors of one or more independently operated electrical devices. The preferred 60 embodiment of the enclosure includes a hinged, slidable, or removable panel that can be secured. With the securable panel removed, the electrical power connectors of the independently operated electrical devices to be controlled are connected to an electrical connector 65 receptacle located in the housing. The end of the electrical power cables and the electrical power connectors of the independently operated electrical devices enter

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through notches in the wall of the securable panel; the securable panel may be designed to prevent reverse passage of the electrical power connector therethrough. The receptacle is electrically connected to the electrical apparatus switch and power plug plate which make the direct connection to the power source.

A locking device, operated by the manual setting of indiced disks to a predetermined setting, is provided on a front panel of the housing. Once the indiced disks are set for operation in the predetermined setting, the adjacent handle can slide to perform two individual functions. Moving the handle in one direction will permit the changing of the predetermined setting on the indiced disks to another value. Moving the handle in the other direction will open an enclosing lid on a front panel of the housing. Once the enclosing lid is opened, three sets of objects are exposed. The enclosed attachment screw allows the authorized user to install or remove the electrical apparatus from a wall outlet. The enclosed pair of spring-loaded restraining pins allow the removal of the securable panel that prevents reverse passage of the electrical power connectors attached to the electrical apparatus' receptacle. This operation is performed by depressing both spring-loaded restraining pins simultaneously while pulling the securable panel in the direction away from the electrical apparatus' receptacle. The third device exposed is an electrical switch. One side of the switch allows current to flow from the power source through the electrical apparatus to the independently operated electrical devices. Depressing the other side of the switch stops the flow of current from the power source through the electrical apparatus to the independently operated electrical devices. In the preferred embodiment of this invention, only the side of the switch which stops the flow of current can be depressed through a membrane in the enclosing lid when the enclosing lid is in the closed position.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional objects and advantages of the invention will become apparent in the course of the following specification when taken in connection with the accompanying drawings in which:

FIG. 1 is a perspective view of the apparatus for controlling use of electrically powered equipment made in accordance with the present invention with corner of upper housing broken away to show an attachment post 92; a securable enclosure 88 of the electrical apparatus shown removed from the electrical apparatus; and, an enclosing lid 78 in the open position;

FIG. 2 is a view of the apparatus for controlling use of electrically powered equipment made in accordance with the present invention with an upper housing 12 and securable enclosure 88 shown removed from the electrical apparatus and a sliding handle 68 shown attached to a sliding bracket assembly 70;

FIG. 3 is a cross-sectional view taken along the line

3— 3 of FIG. 2;

FIG. 4 is a cross-sectional view taken along the line

4— 4 of FIG. 1;

FIG. 5 is a diagrammatical detail view of a complete indiced disk 66 and a disk housing 198 with a notched shaft 214 removed for clarity;

FIG. 6 is a perspective view of notched shaft 214 with a portion of angled shaft plate 212 broken away to expose a set of unnotched sections 224 and a set of notched shaft positions 228; and,

FIG. 7 is an alternate embodiment of the apparatus for controlling use of electrically powered equipment with a power cable 234 and a power connector 236 in place of the assembly including a power plug plate 172, a plug power blade 176, a plug neutral blade 178, and a plug ground blade 180, not shown.

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-continued

Reference Numerals in Drawings

10 apparatus for controlling use of electrically powered equipment (electrical apparatus)

12 upper housing (enclosure)

14 lower housing (enclosure)

16 electrical connector receptacle (receptacle)

18 locking device

20 electrical switch (switch)

24 bottom panel end (end)

28 side wall

32 side wall

34 lower side wall upper edge

(upper edge) 36 lower side wall upper edge

(upper edge) 38 lower side wall upper edge

(upper edge) 40 side wall step (step portion) 44 upper side wall lower edge

(lower edge) 46 upper side wall lower edge

(lower edge) 48 upper side wall lower edge

(lower edge) 50 upper side wall 54 upper side wall 58 upper panel end (end portion) 60 upper panel end (end portion) 62 upper panel end (end portion) 66 indiced disk

70 sliding bracket assenbly (assembly) 74 hole

78 enclosing lid (lid)

82 upper housing slot (slot)

86 securable enclosure tab (tab)
90 screw
94 hinge

98 pin restraining plate (plate)
102 support plate slot
106 lid divider
110 power-off switch side
114 top panel (panel)
118 bottom panel (panel)
120 notched tab
122 securable enclosure guide
124 securable enclosure guide
126 securable enclosure edge
128 securable enclosure edge
132 upper panel edge
134 securable enclosure edge

138 tab interface hole (hole)

142 restraining pin (pin)

146 retaining notch

150 electrical power connector

152 end of electrical power cable (end)

154 switch support plate (plate)

158 vertical support

162 attachment screw sleeve

166 support rod

170 restraining pin lip

172 power plug plate (plate)

176 plug power blade (blade)

178 plug neutral blade (blade)

180 plug ground blade (blade)

184 power lead

186 power switch lead

188 receptacle power screw

192 receptacle neutral screw

Reference Numerals in Drawings

10

15

20

25

DETAILED DESCRIPTION OF THE
INVENTION

With reference to the drawings, there is shown in FIGS. 1, 2, 3, 4, and 7 an apparatus for controlling use of electrically powered equipment or electrical apparatus 10, in accordance with the present invention, comprising of an upper housing or enclosure 12, a lower housing or enclosure 14, in which a suitable, wellknown electrical connector receptacle or outlet 16, a locking device 18, and a suitable, well-known electrical switch 20 are mounted. The receptacle 16 is of conventional type, and contains at least one plug outlet or plug receiving aperture 240, two being shown in the drawings.

Enclosure 14 comprises a bottom panel 22 with a plurality of ends 24 of which there are integrally formed side walls 26, 28, 30, 32. Upper edges 34, 36, 38 of side walls 26, 28, 30 include a step portion 40. Step portions 40 each accept a lip 42 which is formed on lower edge 44, 46, 48 of upper side walls 50, 52, 54 which are integrally formed on end portions 58, 60, 62 of an upper panel 64 of enclosure 12. Note that neither side wall 32 nor upper side wall 56 include the aforementioned step portion/lip combination in the current embodiment,

A plurality of indiced disks 66 and a sliding handle or button 68 partly project beyond enclosure 12 so they may be manually operated. Handle 68 is attached to a sliding bracket assembly 70 by a rivet or fastener 72 after being inserted through a hole 74 of assembly 70. A recessed area 76 is exposed when an enclosing lid or panel 78 is in the open position. Lid 78 is sized such that area 76 as well as its contents cannot be accessed when lid 78 is in the closed position. Enclosure 12 also includes a set of upper housing slots or sleeves 80,82 sized and positioned to allow a set of securable enclosure tabs or blades 84, 86 to project through slots 80, 82. Securable enclosure tabs 84, 86 are attached to a securable enclosure or device 88 which will be described presently.

As is best shown in FIGS. 1, 2, and 4, enclosure 12 is connected to bottom panel 22 of enclosure 14 by means of a plurality of screws or fasteners 90 which extend through a set of holes 238 to engage a plurality of attachment posts or columns 92 which are integrally formed to the bottom of enclosure 12. FIG. 1 shows lid 78 attached to upper panel 64 by a hinge 94. A wound spring 96, attached to hinge 94 and pushing against lid 78 and a pin restraining plate 98 holds lid 78 open. When lid 78 is in the closed position, a notched tab 100 8

projects through a support plate slot or cutout 102 and is engaged by a lock operator 104 as shown in FIG. 2, preventing wound spring 96 from pushing open lid 78. When lid 78 is in the closed position, a lid divider 106 bisects the face of electrical switch 20 to prevent a user 5 from depressing a power-on switch side 108 through a flexible membrane 112 located over a power-off switch side 110.

. In FIG. 1, securable enclosure 88 has been shown removed from electrical apparatus 10. Securable enclo- 10 sure 88 is used to restrict access to electrical power connectors 150 located in an electrical power connector compartment 242. Securable enclosure 88 includes a top panel 114, a front panel 116, and a bottom panel 118 which consists of a plurality of notched tabs or elements 15 120. Top panel 114 includes two securable enclosure tabs 84, 86 which project under the top wall of panel 64 through slots 80, 82. The dimensions of panels 114,116 are chosen such that securable enclosure 88 contacts the lower surface of a set of securable enclosure guides 122, 20 124, securable enclosure edges 126, 128 contact the inside of side walls 30,28 and bottom panel 118 contacts the bottom of panel 22 when securable enclosure 88 is in the closed position. The inside of panel 116 will be flush with the face of a lower base edge 130. With securable 25 enclosure 88 in the closed position, an upper panel edge 132 will contact a securable enclosure edge 134 and a set of tab interface holes or cutouts 136, 138 will be aligned over a set of restraining pins or columns 140, 142 such that the tops of pins 140,142 protrude through 30 holes 136,138 and prevent removal of securable enclosure 88.

Panels 116,118 of securable enclosure 88 include a set of two retaining notches or slots 144, 146 which are large enough to admit a set of electrical power cables or 35 cords like 148. The number of notches provided is equal to the number of outlets provided for in receptacle 16 with each notch aligned with an outlet. When securable enclosure 88 is attached to electrical apparatus 10, each retaining notch 144, 146 shown is only wide enough to 40 accommodate the width of an ordinary end 152 of an electrical power cable 148 thereby preventing the passage of an electrical power connector 150 through the notch.

FIG. 2 shows switch 20 attached to a switch support 45 plate 154 which is attached by a plurality of screws or fasteners 156 to a plurality of vertical supports 158 that are integrally connected to panel 22. As shown in FIG. 3, an attachment screw or fastener 160 projects through plate 154 and an attachment screw sleeve or housing 50 162 that is integrally connected to panel 22. Attachment screw 160, which is prevented from sliding out by a lockwasher 164, can be secured to a wall receptacle which is well known and not shown.

FIGS. 1, 2, and 3 show pin 142 positioned over a 55 support rod or column 166 that is integrally connected to panel 22. A helical spring 168 is compressed when enclosures 12, 14 are joined, causing plate 98 to apply pressure on a restraining pin lip or edge 170. Plate 98 is an integral part of panel 64. The top of pin 142 is high 60 enough to restrict the movement of securable enclosure tab 86 unless downward pressure is applied to pin 142 with sufficient force to position it below the bottom of securable enclosure tab 86. As is shown in FIG. 2, pin 142 is one of two pins 140, 142 which both operate in 65 the manner which has just been described.

FIGS. 2 and 3 show a power plug plate or device 172 attached to panel 22 by a plurality of formed rivets or

fasteners 174 whose manufacturing process is wellknown. As shown in FIGS. 2 and 3, a plurality of formed rivets 174 are also used to attach receptacle 16 to side wall 32 and locking device 18 to a set of fixture supports or columns 200, 202.

FIGS. 2 and 3 show plate 172 provides for the attachment of a plug power blade or lead 176, a plug neutral blade or lead 178, and a plug ground blade or lead 180 by means of a plurality of grommets or fasteners 182. Blades 176, 178, 180 extend through panel 22 so they may be connected to a source of power. Electrical current flows from blade 176 to switch 20 by means of a power lead or wire 184. Depressing power-on switch side 108 allows electrical current to flow through switch 20 into receptacle 16 by means of a power switch lead or wire 186 which is attached to receptacle 16 at a receptacle power screw or fastener 188. Blade 178 is connected to receptacle 16 by means of a neutral lead or wire 190 which is attached to receptacle 16 at a receptacle neutral screw or fastener 192. Blade 180 is attached to receptacle 16 by means of a ground lead or wire 194 which is affixed to receptacle 16 at a receptacle ground screw or fastener 196. The flow of current through the elements described above is possible only when electrical apparatus 10 is connected to a source of electrical power.

FIGS. 1, 2, 4, and 5 show locking device 18 whose main function is to keep lid 78 in the closed position. As presently preferred, locking device 18 is adapted to enclose all its mechanisms within a disk housing or enclosure 198 which is attached by a plurality of formed rivets or fasteners 174 to fixture supports 200,202 which are integrally connected to panel 22. Handle 68 is permanently attached to assembly 70 by rivet 72 after being placed through an upper panel slot or cutout 204. FIG. 4 shows handle 68 in its installed position. Assembly 70 is aligned such that a plurality of integrally formed bracket tabs 206 contact the right side of a shaft support plate or bracket 208 and a plurality of bracket tabs 210 contact the left side of an angled shaft plate 212. Assembly 70 rests on the upper edges of support plate 208 and angled shaft plate 212.

Within disk housing 198 is a notched shaft 214 which is fixedly attached to angled shaft plate 212 on one end and freely supported by support plate 208 on the other end. Notched shaft 214 is clearly shown in FIG. 6. As shown in FIGS. 2,4, and 5, a disk guide plate 216 underneath support plate 208 keeps indiced disks 66 from moving to the left or right. A helical compressed spring 218 normally urges a plurality of interlocking outer shafts or sleeves 220 together, with the rightmost outer shaft 220 end pressed against support plate 208.

Indiced disks 66 and outer shafts 220 are free to rotate about notched shaft 214 when their outer shaft tabs 222 are located at unnotched sections 224 as shown in FIGS. 4,5, and 6. A set of indiced disk tabs 226 prevent indiced disks 66 and outer shafts 220 from rotating separately at unnotched sections 224. When outer shaft tabs 222 are aligned with the notch in notched shaft 214, outer shafts 220 are free to move left or right. Motion will occur only when all outer shafts 220 are aligned as described above and a force is applied to handle 68 in the proper direction. Under the aforementioned conditions, applying a force to the left on handle 68 will cause tabs 206 to apply a force to support plate 208, resulting in outer shaft tabs 222 moving to a set of notched shaft positions 228. Indiced disks 66 are kept in their original position by disk guide plate 216 and are free to rotate