Hinge assembly for an insulated glass door.

(54) Title: HINGE ASSEMBLY FOR AN INSULATED GLASS DOOR.

(54) Title: HINGE ASSEMBLY FOR AN INSULATED GLASS DOOR.

(57) Summary

The hinge assembly comprises a housing for mounting in a cabinet and a post element for mounting on a door and for rotation with respect to the housing; a first electrical contact is mounted within the housing for connection to an electrical power source in the cabinet and a second electrical contact is arranged on the post in electrical contact with the first contact for connection to an electrical device on the door; In one embodiment, the electrical contacts rotate with respect to each other as the pole member rotates in the housing, while in other embodiments the electrical contacts remain stationary with respect to each other as the pole member rotates in the housing. accommodation.

(57) Abstract The hinge assembly comprises a housing for mounting on a cabinet and a post member for mounting on a door and for rotation relative to the housing. A first electrical contact is mounted within the housing for connection to a source of electrical power in the cabinet and a second electrical contact is disposed in the post in electrical contact with the first contact for connection to an electrical appliance in the door. DESCRIPTIVE MEMORY In one embodiment, the electrical contacts rotate relative to each other as the post member pivots on the housing while in other embodiments; the electrical contacts remain statlonary relative to each other as the post member pivots on the housing.

HINGE ASSEMBLY FOR AN INSULATED GLASS DOOR

This application claims the benefit of Provisional Patent Application 62 / 189,585, filed July 7, 2015.

This invention relates to a hinge assembly for a door. More especially, this invention relates to a hinge assembly for a door having an electrical device in or on it. Even more especially, this invention relates to a hinge assembly for an insulated glass door having lighting and / or heating means therein.

As is known, various doors have been constructed to be mounted in a hinged mode to a cabinet or within a door frame. In particular, doors have been constructed to be hinged over the front of a cabinet, such as a refrigerated cabinet used in many supermarkets, and the like. Typically, such a door is constructed of a rectangular shaped insulated glass unit (VA unit) with at least a couple of panes of glass (or lighter ones) and a perimeter spacer system that functions as a means of holding the panes of glass in parallel separated relationship. In addition, in some cases, the glass unit has been electrically heated to prevent surface condensation on the glass sheets while, in other cases, a lighting fixture has been incorporated into the glass unit to illuminate the interior of the cabinet in which the door is mounted.

In situations where electrically heated glass is required, the VA unit can be provided with a transparent electrically conductive heating film attached to at least one of the sheets and a pair of electrically conductive bus bars mounted in electrical contact on the coated sheet or sheets of glass on opposite sides of the coated sheet or sheets of glass.

Various types of electrical connectors have also been used to supply electrical power to doors with VA units, as described in US 3,760,157.

It is an object of the invention to provide a hinge assembly for a door that allows the supply of electrical power to an electrical device within the door.

It is an object of the invention to provide a hinge assembly for a door having an insulated glass unit that enables the supply of electrical power to an electrical lighting device within the door glass unit.

It is an object of the invention to provide a hinge assembly for a door having an insulated glass unit which allows the supply of electrical power to electrically conductive bus bars within the door glass unit.

It is an object of the invention to provide a door hinge assembly for a refrigerated cabinet having an insulated glass unit that enables the supply of electrical power to an electrical lighting device within the glass unit.

Briefly, the invention provides a hinge assembly for a door that will be mounted in a cabinet, for example, a door that includes an insulated glass unit having at least one pair of glass sheets arranged in parallel relationship and defining a separation between them and an electrical device within the space. The electrical device in the door can be a lighting fixture having one or more fluorescent bulbs or a series of LED lamps or it can be a transparent electrically conductive heating film attached to at least one of the leaves and a pair of electrically busbars. conductive conductors mounted in electrical contact in the heating film.

The hinge assembly comprises a housing for mounting in the cabinet and a post element for mounting on the door and for rotation with respect to the housing.

In accordance with the invention, the hinge assembly has a first electrical contact means mounted within the housing for connection to an electrical power source in the cabinet and a second electrical contact means arranged on the pole in electrical contact with the first contact means for connection with the electrical device on the door.

The hinge assembly housing has a wall for vertical deposition against the cabinet and a base projecting from one end of the wall to receive the first electrical contact means. In addition, the wall has an opening and an electrical line extending from the electrical contact means at the base through the opening and into the cabinet.

The post element of the hinge assembly has a wall for vertical arrangement against the door and a dependent tubular portion that is rotatably arranged at the base of the housing for rotation of the post element with respect to the housing.

In one embodiment, the electrical contact means on the post is fixed with respect to the post and is capable of rotating with the post with respect to the electrical contact means in the housing. When the pole is mounted in the housing, an electrical contact is made between the two contact means so that electrical power can be supplied from the power source in the cabinet to the device in the door.

In another embodiment, the electrical contact means in the post includes a barrel that is fixed in place to allow the post to rotate around the barrel and the electrical contact means in the housing includes a vertical bolt that is inserted into the barrel to complete an electrical circuit.

In a third embodiment, the electrical contact means arranged on the post is fixed with respect to the electrical contact means in the housing and the post is rotatable with respect to the electrical contact means to limit wear on the two electrical contact means.

The hinge assembly can be constructed to position the door in different positions with respect to the cabinet, as described in US Patent 6,152,554. In this regard, the tubular portion of the post member fits into a bore in a cam member of the housing, and the post member has a cam member with a circumferential cam surface that coincides with a cam surface of the cam member. cam in housing 10. The cam surfaces are formed so that as the post element rotates in the housing, the door can be moved from a closed position on the cabinet to an intermediate open position and then to a fully open position as is conventional. Furthermore, during the rotation of the post element in the cam element, the post element can move vertically upwards.

These and other objects of the invention will become more apparent from the following description taken in conjunction with the accompanying drawings wherein:

Figure 1 illustrates a front view of a hinge assembly for a door that mounts to a cabinet according to the invention;

Figure 2 illustrates an exploded perspective view of the hinge assembly of Figure 1;

Figure 3 illustrates a rear view of the housing of the hinge assembly of Figure 2 and the electrical contact means at the base thereof;

Figure 4 illustrates a perspective view of a component of the electrical contact means for mounting on the base of the housing;

Figure 5 illustrates a perspective view of the second component of the electrical contact means of Figure 3;

Figure 6 illustrates a top view of the component of Figure 5;

Figure 7 illustrates a cross-sectional view taken on line 7-7 of Figure 6;

Figure 8 illustrates a schematic view of the post element of the hinge assembly of Figure 1 as it is connected to a lighting apparatus in accordance with the invention;

Figure 9 illustrates an exploded perspective view of a hinge assembly having a second embodiment of the electrical contact means according to the invention;

Figure 10 illustrates a rear view of the housing of the hinge assembly of Figure 9 and the electrical contact means at the base thereof;

Figure 11 illustrates a rear perspective view of the housing of Figure 9;

Figure 12 illustrates an exploded perspective view of an electrical contact means for mounting in the housing of Figure 11;

Figure 13 illustrates an exploded perspective view of a hinge assembly with a third embodiment of a modified electrical contact means in accordance with the invention;

Figure 14 illustrates a cross-sectional view of the hinge assembly of Figure 13;

Figure 15 illustrates an exploded perspective view of a hinge assembly with a fourth embodiment of a modified electrical contact means in accordance with the invention;

Figure 16 illustrates a cross-sectional view of the hinge assembly of Figure 15; and

Figure 17 illustrates an exploded view of the post element and the electrical contact means therein of the hinge assembly of Figure 15.

Referring to Figure 1, the hinge assembly 10 is constructed for mounting a door 11 in a cabinet 12 and especially a door 11 with an insulated glass unit 13 of at least one pair of parallel glass sheets 14 with one or more electrical devices 15, such as a light and a heater, within the space between the panes of glass 14.

Cabinet 12 is typically a refrigerated cabinet with a power source (not shown) housed therein in a conventional way.

Referring to Figure 2, the hinge assembly 10 includes a housing 16 for mounting to cabinet 12 and a post element 17 for mounting to door 11 and for rotation relative to housing 16.

Housing 16 has a wall 18 for vertical deposition against the cabinet (not shown) and a base 19 projecting from the lower end of wall 18. Wall 18 has three openings 20 that serve for passage of mounting screws (not shown) to secure housing to cabinet 12. Base 19 is hollow for purposes described in the following.

_{Housing 16 also includes cam member 21 that is fixedly mounted to base 19 to cause post member 17 and door 11 to move vertically upward as is known. This cam element 21 has a circular surface of} z cam 22 at the top for raising and lowering the post element 17 and a central bore 23 concentrically within the circular cam surface 22. The cam element 21 is formed of a plastic material, as is known, while the housing 16 is formed of metal.

The post element 17 is formed of metal in one piece and has a wall 24 for vertical arrangement against the door 11 and a dependent tubular portion 25 which is rotatably disposed within the bore 23 of the cam element 21 in the housing 16. Wall 24 has three openings 26, two of which are for passage of mounting screws (not shown) to secure post element 17 to door 11.

Hinge assembly 10 also includes a cover 27 to fit over the post element 17 in a conventional manner.

To supply electrical power from a power source in cabinet 12 to electrical device 15 in door 11, an electrical contact means is provided in housing 16 and post element 17 of hinge assembly 10 to make contact for power transfer when door 11 is mounted on cabinet 12, that is, when pole element 17 is inserted into housing 16.

Referring to Figure 2, in one embodiment, the post element 17 has a first electrical contact means 28 that mounts in a fixed manner within the tubular portion 25 and extends downwardly from the tubular portion 25. contact means 28 is in the form of a DC Power Socket, such as Model PP3-002BH sold by CUI Inc. of Tualatin, Oregon (CUI).

An electrical line 29 (see Figure 8) extends from the contact means 28 through the tubular portion 25 of the post element 17 and one of the openings 26 within the door 11 and the electrical device 15 at the same.

The post element 17 also has a cam element 30 with a circumferential cam surface 31 which coincides with the circular cam surface 22 of the cam element 21 in the housing 16 to allow the post element 17 and the door 11 to move vertically. upward, as is known, as the door moves from a closed position on cabinet 12 to an open position in response to rotation of tubular portion 25 within bore 23 of cam element 21. As known , the cam surface 22 is notched at predetermined positions to receive a dependent catch on the cam member 30 to hold the door 11 in a partially open position.

Referring to Figures 2 and 3, a second electrical contact means 32 is mounted within the hollow base 19 of housing 16 below and below cam element 21 for connection to a source of electrical power in cabinet 12 ( not shown) through an electrical line (not shown) extending from electrical contact means 32 within cabinet 12 (not shown).

Referring to Figure 3, electrical contact means 32 includes a mounting plate 34 that slidably mounts to base 19 through a pair of vertically spaced flanges 35 integral with base 19 on each of the two sides of plate 34.

As shown in Figure 4, mounting plate 34 is flat and has a vertical annular collar 36 at one end with a pair of flat reinforcing walls 37 on opposite outer sides of collar 36 that serves to hold plate 34 firmly in place. its place between flanges 35 of base 19. Plate 34 includes an opening 38 within collar 36 and projects into the plane of collar 36 to define an annular flange 39.

Flange 39 is sized to seat a spring of turns 40 (see Figure 3).

Referring to Figures 5, 6 and 7, the electrical contact means 32 also includes a metal retaining nut washer 41 having an internal thread 42 for threading onto the top of a DC Power Plug 43 (see Figure 3), such as a Model PJ-065B, sold by CUI, and installed in the base 19 of the housing 16.

The nut washer 41 also includes an annular cavity 44 on an underlying side to receive an upper end of the coil spring 40 and a vertical annular collar 45 on the upper side for connection to the tubular portion 25 of the post element 17.

The power line (not shown) extends from the DC Power Plug 43 of contact means 32 to connect to the power source (not shown) in cabinet 12.

Referring to Figure 2 , when door 11 is closed on cabinet 12, tubular portion 25 of post element 17 butts into collar 45 of nut washer 41 and the DC power socket 28 extends through the socket washer. nut 41 into Male DC Power Plug 43 to form an electrical connection. In addition, the coil spring 40 is compressed between the nut washer 41 and the mounting plate 34.

When the door is opened, the tubular portion 25 of the post element 17 rotates in the collar 45 of the nut washer 41 and rises vertically upward as the coil spring 40 expands to deflect and hold the nut washer 41 in place. contact with the tubular portion 25 of the pole element 17. At the same time, the DC power socket 28 on the rising pole element 17 rotates with respect to the stationary DC power socket 43 on the base 19 of the housing 16 .

Since the DC power plug 43 in the base 19 of the housing 16 remains in electrical contact with the DC power socket 28 in the pole element 17, the electrical device 15 in the door 11 is continuously supplied with power. electrical. In this regard, the amount of power supplied to the appliance can be kept at a low capacity to avoid electric shock to door users 11. For example, the DC Power Socket 28 has a capacity of 16VDC at 8A and the Male DC Power Plug 43 is rated for 24VDC at 5A.

Referring to Figures 9 to 12, where like reference characters indicate parts similar to the above, the electrical contact means employed in the hinge assembly 10 may be of a different construction.

For example, as illustrated in Figure 12, the contact means 28 'for mounting on the pole element 17 (not shown) is in the form of a barrel 46 with a pair of vertical wires 47 and an annular flange 48 at the bottom. The contact means 32 'for mounting on the base 19 of the housing 16 includes a mounting plate 49 that carries a DC power socket 50 with a vertical bolt 51 for insertion into the barrel 46 to complete an electrical circuit with the cables. 47.

In addition, a spring 52 is provided for mounting on the base 19 of the housing 16 to bias the mounting plate 49 upward to keep the bolt 51 in electrical contact with the wires 47 within the barrel 46 during the twisting and vertical movement of the element. of post 17 in housing 16.

Referring to Figure 11, a centering knob 53 is provided in base 19 of housing 16 to center spring 52 and hold bolt 51 in position.

As illustrated in Figure 9, barrel 46 (not shown) is securely mounted within tubular portion 25 of post member 17 with flange 48 butted against the lower end of tubular portion 25 and the two cables 47 of the barrel extending to near the top of the tubular portion 25. The power line (not shown) to supply power in a door could be connected to the two wires 47 and the power line (not shown) to supply power from the source inside the cabinet could be connected to suitable terminals of the power socket 50.

In this embodiment, the post element 17 fits with the barrel 46 of the contact means 28 'and the housing 16 fits with the other contact means 32' separated from the post element 17. Subsequently, the tubular portion 25 of the element of post 17 is inserted into the bore 23 of the cam element 21 with the bolt 51 of the contact means 32 'in the housing 16 moving inside the barrel 46 to make electrical contact with the two wires 47.

Subsequently, As the post element 17 rotates in the housing 16, an electrical connection is maintained between the two contact means 28 'and 32'.

Referring to Figures 13 and 14, where like reference characters indicate parts similar to the above, the electrical contact means employed in the hinge assembly 10 may be of a different construction to reduce wear on the electrical contact means during the repeated opening and closing of a door in a refrigerated cabinet.

Referring to Figure 13, the hinge assembly 10 includes a housing 16, a post element 17, and a cam element 21 as described above.

Referring to Figure 14, an electrical contact means 54 includes an electrically conductive barrel 55 with a pair of vertical wires 56, such as a Model R51-Y001 Fixture with a Connector Switch, sold by CUI, and a bearing. of inner sleeve 57 fixed concentrically on the outer surface of barrel 55, as by threading.

The electrical contact means 54 is arranged in the dependent tubular portion 25 of the post element 17 with the inner sleeve bearing 57 with a small gap from the tubular portion 25 to allow the post element 17 to rotate around the means of electrical contact 54. In addition, the inner sleeve bearing 57 has an outer annular shoulder 58 which is butted into the lower end of the tubular portion 25.

Inner sleeve bearing 57 is formed of any suitable material, such as a Polyamide Nylon®, and is rotatably received in barrel 55. Thus, as post element 17 rotates in cam element 21, the tubular portion 25 of post member 17 rotates in inner sleeve bearing 57.

As illustrated, barrel 55 has an annular flange 59 at the bottom against which inner sleeve bearing 57 butts.

Referring to Figure 13, other electrical contact means 60 such as a Model R51-230 Switchcraft 230 Connector sold by CUI includes a mounting base 61 having a vertical bolt 62.

The mounting base 61 is dimensioned to slide into the base 19 of the housing 16 and is seated in a spring clamp assembly 63 formed of an apertured flat plate 64 and a coil spring 65. As illustrated, the spring spring Coils 65 are positioned concentrically around a vertical button 66 on plate 64 and held in place on plate 64 by a pair of tabs 67 that are integrally formed on plate 64 to connect over a coil of 65 at diametrically opposite locations .

Bolt 62 of electrical contact means 60 in housing 16 is dimensioned to be slidably received in barrel 55 of electrical contact means 54 in post element 17 in a friction fit manner that prevents bolt 62 and the barrel 55 rotate relative to each other while allowing bolt 62 and barrel 55 to make electrical contact. As illustrated, bolt 62 is of a circular cross-section and barrel 55 has a circular cross-section bore to coincidentally receive bolt 62. Complementary cylindrical shapes allow for ease of orientation of bolt 62 and barrel 55 .

Spring 65 serves multiple purposes. First, when the electrical contact means 60 is assembled to the base 19 of the housing 16, the spring 65 serves to hold the electrical contact means 60 in place and to center the bolt 62. Second, when the post element 17 is placed in place in housing 16, spring 65 serves to keep bolt 62 in electrical contact with barrel 55 of electrical contact means 54 on post element 17.

Spring 65 serves to bias the two means electrical contact contact 54, 60 vertically upward during the upward and turning movement of the post member 17 while biasing the inner sleeve bearing 57 into engagement with the tubular portion 25 of the post member 17.

In this embodiment, the post element 17 is fitted with the barrel 55 and the inner sleeve bearing 57 of the contact means 54 and an electrical line 29, as in Figure 8, extends from the cables 56 of the means of connection. contact 54 through tubular portion 25 of post element 17 and one of the openings (not shown) within a door (not shown) and an electrical device (not shown) therein. In addition, housing 16 fits with other contact means 60 spaced from pole element 17 and an electrical line 2 9 'extends from electrical contact means 60 within a cabinet (not shown).

During assembly of the hinge assembly 10, the tubular portion 25 of the post element 17 is inserted into the bore 23 of the cam element 21 with the bolt 62 of the contact means 60 in the housing 16 moving within the barrel 55 to make electrical contact with it.

Subsequently, as the post element 17 rotates in the housing 16 and rotates around the inner sleeve bearing 57, an electrical connection is maintained between the two contact means 54 and 60 without a relative rotation between the two means contact numbers 54 and 60.

Referring to Figures 15 to 17, where like reference characters indicate parts similar to the above, the electrical contact means employed in the hinge assembly 10 may be of a different construction to reduce wear on the electrical contact means during the repeated opening and closing of a door in a refrigerated cabinet.

In this embodiment, an electrical contact means 68 is constructed for mounting on the pole element 17.

As illustrated in Figure 17, electrical contact means 68 is, for example, a Switchcraft connector 152B having an electrically conductive barrel 69 with a perforation 70 (see Figure 16) at one end, an annular collar 71 at that end. end and a pair of vertical wires 72 at the opposite end.

To mount the electrical contact means 68 to the tubular portion 25 of the post member 17, a female connector cam 73 of tubular shape is secured to the barrel 69. For example, the barrel 69 is externally threaded and the cam of Connector 73 is internally threaded to be threaded onto barrel 69 with connector cam 73 butted against collar 71 of barrel 69. In addition, a sleeve-shaped cam fastener 74 is inserted through the tubular portion 25 of the post member 17 and is secured as if by threading over the barrel 69 until it engages with the female connector cam 73.

As illustrated , the female connector cam 73 has a main portion 75 of a diameter to match the outer diameter of the tubular portion 25 of the post member 17 and a reduced diameter portion 76 to be slidably received in the tubular portion 25 of the post member. 17 with a slight gap.

The cam fastener 74 has an outside diameter to be slidably received in the tubular portion 25 of the post member 17 and to be butted against the reduced diameter portion 76 of the female connector cam 73. Cam fastener 74 is internally threaded at least at one end to be threaded onto barrel 69 and has a collar 77 at the upper end, as seen, with a plurality of equidistant slots 78 (e.g., four slots) to facilitate the threading of the cam fastener 74 onto the barrel 69, for example, by means of a screwdriver.

The female connector cam 73 and the cam clip 74 are formed of a plastic material, such as a polyamide sold under the brand name NYLON.

To mount the electrical contact means 68 on the post element 17, the female connector cam 73 is threaded onto the barrel 69 and is butted against the collar 71.

Next, the female connector cam 73 is inserted into the tubular portion 25 of the post member 17 with the reduced diameter portion 76 butted against the end of the tubular portion.

Cam clip 74 is then inserted through tubular portion 25 of post member 17 with slight radial clearance to ensure rotation of post member 17 in cam clip 74 during use. In addition, the cam fastener 74 is threaded onto the barrel 69 in connection with the reduced diameter portion 76 of the female connector cam 73.

Cam clip 74 is of a length that collar 77 is spaced from the top of tubular portion 25 of post member 17 thus allowing post member 17 to move vertically relative to cam clip 74 during use.

When assembled, the female connector cam 73 is secured to the barrel 69 for butting against one end of the tubular portion 25 of the post member 17 with the reduced diameter portion 76 slidably mounted on the tubular portion 25 and the cam fastener 74 it is secured to barrel 69 and slidably mounted on tubular portion 25 with collar 77 projecting from and for mating against an opposite end of tubular portion 25.

In fact, power line 29 (not shown) at a Electrical device in a door 11 can be threaded through cam fastener 74 and secured to wires 72 prior to insertion of barrel 69 and female connector cam 73 into tubular portion 25 of post element 17.

The other electrical contact means 60 is constructed for mounting in the housing 16 and is similar to the electrical contact means 60 described above and includes a mounting plate 61 having a vertical bolt 62 for sliding into the bore 70 of the electrical contact means. 68 and making electrical contact with it.

Mounting plate 61 is sized to slide into base 19 of housing 16 and is seated on coil spring 79. As illustrated in Figure 16, coil spring 79 is positioned concentrically in housing 16 and it is held in place by a pair of tabs 80 that are integrally formed in housing 16 to connect over a coil of spring 79 at diametrically opposite locations.

Bolt 62 of electrical contact means 60 in housing 16 is dimensioned to be slidably received in bore 70 of barrel 69 of electrical contact means 68 in post element 17 in a friction fit manner that prevents the bolt from 62 and barrel 69 rotate relative to each other while allowing bolt 62 and barrel 69 to make electrical contact. As illustrated, bolt 62 is of a circular cross section and barrel 69 has a bore 70 of circular cross section to coincidentally receive bolt 62. Complementary cylindrical shapes allow for ease of orientation of bolt 62 and barrel 69.

Suitable stops (not shown) are integrally formed in the form of flanges within the base 19 of the housing 16 to limit the upward movement of the mounting plate 61 of the electrical contact means 60 through the spring 79. As in The foregoing, spring 79 serves to hold electrical contact means 60 in place during assembly while centering bolt 62.

After mounting the hinge assembly 10 'on a door 11 and the cabinet 12 as indicated in Figure 1 and connecting the electrical power lines to an electrical power source in the cabinet and an electrical device 15 in the door 11, the door 11 can be opened and closed in the cabinet 12 multiple times without the wear of the two electrical contact means 60, 68 with each other. Instead, as the post member 17 rotates, the tubular portion 25 rotates in the cam holder 74 while the cam holder 74 remains fixed in place in the barrel 69 of the electrical contact means 68. In this regard, the radial spacing of the tubular portion 25 from the post member 17 prevents the post member from rotating the cam fastener 74. Furthermore, a slight frictional force between the bolt 62 and the bore 70 of the two contact means 60, 68 ensures that there will be no relative rotation of the bolt 62 in the bore 70.

In this embodiment, the post element 17 fits with the contact means 68 and the housing 16 fits with the other contact means 60 separated from the post element 17. Subsequently, the tubular portion 25 of the post element 17 is inserted into the bore 23 of the cam element 21 with the bolt 62 of the contact means 60 in the housing 16 moving within the bore 70 of the barrel 69 of the medium. contact 68 for making electrical contact therewith.

In fact, the hinge assembly of the invention can be used without cam element 21 in housing 16, for example where post element 17 is required to rotate in housing 16 without vertical movement. In such a case, an element may be mounted on the base 19 of the housing 16 with a central bore to rotatably receive the tubular portion 25 of the post element 17 and with an annular bearing surface having notches to receive a circumferential cam surface 22 of the post element 17 to position a door at intermediate points of the opening or closing. The invention thus provides a hinge assembly for a door, especially a door with an insulated glass unit that allows the supply of electrical power to an electrical device, such as an electrical lighting device and / or electrically conductive bus bars, inside the insulated glass unit in the door.

The invention also provides a hinge assembly for any type of door that employs an electrical device on or in the door that allows the supply of electrical power to the electrical device.