A Ballast

Abstract

A ballast having an electrical connector for establishing contact between external contact lugs of the ballast and stripped ends of supply wires to the ballast. The connector comprises a socket of insulating material, one side of which has apertures for accommodating the contact lugs and another side of which, preferably the opposite side, has apertures for accommodating the ends of the supply wires. The socket is provided with a plurality of resilient elements comprising one or more parts, which at one of their ends can establish a nondetachable contact with one of the contact lugs and at their other end can establish contact with one or more ends of the supply wires. The resilient elements are preferably S-like resilient strips whose ends form an acute angle with an inserted lug, so that the resilient strips exert an axial force on an inserted lug, which prevents the lug from sliding out.

Description

The invention relates to a ballast having connector for establishing contact between a plurality of external contact lugs of the ballast and electric device and the stripped ends of supply wires. The connector may be used with a ballast for gas-discharge lamps provided with the standard external lugs.

Many electric devices or components of electric devices have a plurality of external contact lugs for the connection of the supply wires. It is generally desirable that these devices be easily mounted or exchanged. It is also necessary that the connection between the supply wires and the contact lugs be made or detached quickly. Such devices are known, for example, U.S. specification Pat. No. 2,342,570 for permanently connecting the ends of the supply wires to contact means such as plugs or contact blocks which can be slid onto the lugs of a device. The connection of these known contact means to supply wires is however time-consuming, which is a serious drawback when mounting a large number of devices. The known contact means have the additional drawback that they often require a construction of the contact lugs of the device which deviates from the standard construction. In that case the choice of contact means is of course limited to the contact means fitting on the contact lugs.

Furthermore, devices are known for connecting simple cable sockets to the stripped ends of the supply wires so that the above-mentioned drawbacks are partly avoided. These cable sockets have a bush which fits tightly on the lugs of a device and a portion which is secured to an end of a supply wire by means of a soldered or clamped joint. The contacts established in this manner however present a safety problem because the lugs and cable sockets are exposed.

It is the object of the invention to provide a ballast having a connector for connecting supply wires to the lugs of the supply unit of the ballast in which the above-mentioned drawbacks are avoided.

According to the invention, a ballast having connector of the kind described above is characterized in that the connector includes a socket of insulating material, one side of which has apertures for accommodating the contact lugs, and another side, preferably the opposite side, has apertures for accommodating the ends of the supply wires. A plurality of resilient elements are provided in the socket, one of the ends of the elements can establish a nondetachable contact with one of the contact lugs and the other end can establish contact with one or more ends of the supply wires.

A connector according to the invention may be permanently connected to the lugs of an electric device and is suitable for devices formed with standard contact lugs. The contact lugs are located entirely within the insulating socket when using the connector and is therefore safe to the bare hand. The connection of the supply wires is established by introducing the stripped ends of the wires into the socket which wire ends likewise are located entirely within the socket. The connection may be interrupted by detaching the ends of the wires.

The apertures for the lugs lie preferably on one line in a side face of the socket and the apertures for the ends of the wires in the opposite side face being located on a line parallel to the first mentioned line, but wherein these lines are located at a different height in the socket. A significant feature of this invention is the conservation of space in the direction of the introduced lugs.

The resilient elements which establish the connection between the ends of the wires and the contact lugs may comprise one or more parts. It is possible to compose the resilient elements from a part which provides the contacts and the electric connection and a part which provides the resilient force and which abuts the first part. The resilient elements preferably include resilient strips which are centrally clamped.

An embodiment of a connector for use on a ballast according to the invention which can be connected very quickly and easily to the external lugs includes S-like resilient strips whose ends cooperating with the lugs form an acute angle with an inserted lug. When inserting a lug the said end of the resilient strip will be displaced over a small distance in the direction of movement of the lug, whereafter it forms an acute angle with the lug. The force exerted by the resilient strip on the lug then includes a component which is directed at right angles to the lug and a component which is directed along the axis of the lug, the latter component preventing the lug from sliding out.

In a connector for use on a ballast according to the invention the contact between the ends of the wires and the ends of the resilient strips cooperating therewith can advantageously be established in the same manner as is described above for the lugs. The contact is then established by simply sliding the stripped end of the wire into an aperture of the connector. In this embodiment means are provided to detach the ends of the wires. This means preferably include apertures in a side face of the socket for introducing tools, for example, a screwdriver by which the resilient force on the ends of the wires can be eliminated. The said apertures may be located in the vicinity of the apertures for the ends of the wires, but they may alternatively coincide therewith.

The socket of insulating material preferably comprises two portions, namely a housing the base of which is provided with the apertures for the lugs and a cover provided with the apertures for the ends of the wires.

A connector according to the invention may advantageously be used in combination with current-stabilizing ballasts for gas-discharge lamps. In one preferred embodiment of such a combination, the dimension of the connector in the direction of the contact lugs is smaller than twice the length of a contact lug. As a result of using the connector on the end of a ballast, the overall length of the ballast is not significantly increased. This is quite important when available space is limited.

A ballast according to the invention preferably includes a connector the design of which is such that the connector can be connected to the contact lugs in one manner only. As a result the possibility of erroneous connection of the supply wires is eliminated.

In order that the invention may be readily carried into effect, a few embodiments thereof, will now be described in detail, by way of example with reference to the accompanying diagrammatic drawing, in which:

FIG. 1 is an elevational view of an embodiment of a connector according to the invention, and

FIG. 2 is a cross section taken on the line II--II of the connector of FIG. 1,

FIGS. 3a and b are elevational views of the resilient elements of the connector of FIG. 1, and

FIG. 4 shows an embodiment of a part of a ballast according to the invention.

The cover of a connector used on a ballast is denoted by the reference numeral 1 in FIG. 1. The cover 1 is molded from insulating material, for example, a synthetic plastic material. The reference numerals 2, 3 and 4 denote apertures in the cover for accommodating ends of connection wires. Two apertures 5 and 6 for accommodating the contact lugs of an electric device are provided in the side of the housing of the connector facing the cover. The apertures 5 and 6 are shown by broken lines in the drawing and are located on a line parallel to the line through the apertures 2, 3 and 4.

The cover is again denoted by the reference numeral 1 in FIG. 2 in a cross section of FIG. 1 taken on the line II--II. The housing 7 of the connector is like the cover moulded from insulating material. The resilient element 8 is an S-like resilient strip in this embodiment which is centrally clamped between the cover 1 and a raised edge 9 of the housing 7.

FIG. 3a shows the resilient element 10 formed as a resilient strip and FIG. 3b shows the resilient element 8 likewise formed as the resilient strip of the connector of FIG. 1. One end 11 of the resilient strip 8 may be used to establish contact with a contact lug of a device, and the other end 12 may establish contact with one end of a supply wire. The resilient strip 10 has an end 13 for contact with a lug, and an end 14 which may establish contact with the ends of two supply wires.

In FIG. 4, the reference numeral 15 denotes a ballast for a low-pressure gas discharge lamp according to the invention, which is provided with two standard contact lugs one of which is visible in the Figure and is denoted by the reference numeral 16. A connector according to FIG. 1 is slid onto the lugs. The connector is shown in a cross section. The end 11 of the resilient strip 8 forms an acute angle with the lug 16 so that the connector cannot be removed from the lugs of the device. The end 12 of the resilient strip 8 also forms an acute angle with an inserted wire end 17. The wire end 17 may be detached by introducing, for example, a screwdriver into the aperture 2 of the cover 1 and using it to depress end 12 so as to remove the resilient force on the wire end 17. The design of the housing 7 and the cover 1 of the connector is such that connection to the lugs of the device 15 is possible in one manner only.

Claims

What is claimed is:

1. A ballast comprising a power supply, at least one contact lug on an external end thereof, an electrical connector for establishing electrical contact between said lug and stripped wire ends, said connector comprising a socket of insulating material, a first set of apertures aligned on one side of said socket for receiving said external lug, said apertures having a shape conforming to that of said lugs, a second set of aligned apertures on a side of said socket opposite the side accommodating said first set of apertures, said second set of apertures being arranged for receiving therethrough said wire ends, a substantially S-shaped resilient strip arranged within said socket for establishing electrical contact between said lugs and said wire ends, one of the legs of said strip being arranged for engagement at an acute angle with said lug so that said resilient strip exerts an axial force on said lug thereby preventing the lug from being removed from the socket, and the other leg of said strip being arranged for contact with at least one of said wire ends.

2. The ballast according to claim 1 wherein the common transverse axis passing through the first set of apertures is parallel to and offset from the common transverse axis passing through the second set of apertures.

3. A ballast comprising a power supply unit, a plurality of contact lugs extending externally of said unit, an electrical connector connected on one side thereof to said plurality of external lugs and said electrical connector arranged for connection on the other side thereof to stripped wire ends, comprising a socket of insulating material having a base member and a cover, a plurality of apertures aligned in said base having a shape conforming to said lugs for receiving said lugs therethrough, a second set of aligned apertures in said cover arranged for receiving therethrough said wire ends, a resilient strip member mounted within said socket between said base and said cover for establishing electrical contact between said lugs and said wire ends, said strip comprising a pair of oppositely extending legs resiliently connected by a strip, one of said legs being arranged for engagement at an acute angle with said lugs so that said resilient leg exerts an axial force on said lug thereby securing said lug within said socket between the leg and a wall of said base member and preventing the lug from being removed from the socket, and the other leg being arranged for contact with at least one of said wire ends so as to wedge said wire end between said leg and another wall of said base member, said leg engaging said wire end at an acute angle therewith so as to exert an axial force on said wire end in a direction opposing removal of said wire end from said socket, and means to allow relieving of said axial force on said wire end to thereby permit removal of the wire from the socket.

4. The ballast according to claim 3 wherein said cover is arranged opposite said base and wherein the apertures in the cover for receiving the wire ends are arranged along a line which is parallel to and offset from a line along which the apertures in the base for receiving the lugs are arranged.

5. The ballast according to claim 4 wherein said means for allowing removal of said wire end comprises an aperture in said socket for introducing a tool by which the resilient force of said strip on the wire ends can be eliminated.

6. A ballast for gas discharge lamps comprising a power supply unit, a plurality of contact lugs extending externally of said power supply unit, a connector attached to said external lugs for receiving stripped wire ends and establishing electrical contact between said wire ends and said external lugs, said connector comprising a socket of insulating material, means on one side of said socket for nondetachably engaging said lugs, means on the opposite side of said socket for detachably engaging the wire end comprising a plurality of apertures, a resilient substantially S-shaped strip mounted within said socket having one leg thereof resiliently engageable with the wire ends so as to exert a force in the axial direction of said wire thereby preventing said wire from sliding out of said socket, the other leg being arranged for engagement at an acute angle with said lug so that an axial force is exerted on said leg thereby preventing the lug from being removed from the socket, and means for releasing the axial force on the end of said wire to allow removal of said wire from said socket, the overall dimension of the connector in the direction of insertion of said lugs being less than twice the length of said lugs, and said means for engaging said contact lugs being arranged so that the connector can be attached to the power supply unit in only one manner.