US3441889A - Fluorescent lamp ballast with integral fuseholder and replaceable fuse - Google Patents

Description

BOONE April '29, 1969 INVENTOR. (HR/STQ/HE 3 3004 5 0. B. FLUORESCENT LAMP BALLAST WITH INTEGRAL FUSEHOLDER AND REPLACEABLE FUSE Filed Feb. 9, 196'? United States Patent O 3,441,889 FLUORESCENT LAMP BALLAST WITH INTEGRAL FUSEHOLDER'AND REPLACEABLE' FUSE Christopher B. Boone, Shelton, Conn. (21 Station Square, Bergenfield, NJ. 07621) Filed Feb. 9, 1967, Ser. 'No. 615,008 Int. Cl. H01h 85/24 US. Cl. 337-1 3 Claims ABSTRACT OF THE DISCLOSURE A ballast unit for fluorescent lamps, with an integral, accessible fuseholder and a replaceable fuse. The fuseholder permits the replacement of a burned out fuse with another fuse of the same rating only. The fuseholder is removably secured to the unit by either elliptical or U-shaped fasteners.

BACKGROUND OF THE INVENTION The present invention relates to fluorescent lamp ballasts in general and in particular to such ballasts which are provided with integral current and heat temperature sensitive protective devices.

Known fluorescent lamp ballasts of the above described character are equipped with internal protectors of the resetting type or of the non-resetting type. Both of these types of protectors are intended to protect fluorescent lamp ballasts from abnormal conditions of heat, temperature and current. The resetting type of protector deactivates the circuit when the heat, temperature and current rise beyond a predetermined limit. It reactivates the circuit when the temperature has dropped to a permissible limit. The disadvantage of using this type of protector is the difficulty of determining the location of the faulty fixture until a subsequent deactivation takes place. In presently known non-resetting or integrally built-in fuse equipped ballasts the entire ballast unit must be discarded and completely replaced when the fuse has burned out, since the latter is inaccessible and cannot be replaced. This necessarily results in substantially increased maintenance costs, particularly in illumination installations employing a large number of fluorescent fixtures.

SUMMARY OF THE INVENTION An important object of the invention, therefore, is to overcome the above disadvantages by providing, in combination with a fluorescent lamp ballast integral means therewith permitting the replacement of internal heat temperature and current sensitive protectors, said means being accessible Without any difficulty.

A further object of the invention is to provide means of the above described character which will prevent a permanent destruction of the ballast unit.

Still another object of the invention is to provide means of the above described character which will permit a permanent and positive removal of a faulty fixture from the circuit.

Yet another object of the invention is to provide a device of the above character which will make the location of a faulty fixture possible, while limiting the replacement of the fuse to the rating of the burned out fuse.

A further object of the invention is to provide a device of the above character which will have a flexibility of location and can be mounted in any position in the ballast units casing, under the wireway cover or through an opening in the wireway cover to meet code requirements for accessibility.

Another object of the invention is to provide novel means for securing the fuseholder to the ballast units casing in a simple and time saving manner.

r g 3,441,889 Ice Patented Apr. 29, 1969 The above and other important objects of the invention will become apparent from the following description and the accompanying drawing illustrating one embodiment of the invention.

' It should be understood, however, that this is given only by way of illustration and not of limitation, and that various changes in the detail construction of the invention may be made, without departing from the scope thereof.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of the ballast according to the invention;

FIG. 2 illustrates means of securing the fuseholder to the panel of the ballast;

FIG. 3 is yet another means of securing the fuseholder;

FIG. 3a illustrates another fastener means;

FIG. 4 shows a fuse cap with a fuse inserted therein;

FIG. 5 is a plan view of the metal flange of the fuse proper;

FIG. 6 is a section on line 6-6 of FIG. 5;

FIG. 7 is a plan view of the top portion of the fuseholder showing the opening for insertion of the flange of FIG. 5 therethrough; and

FIG. 8 is an enlarged view of the opening of FIG. 7.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now to the figures in detail, the ballast unit is generally indicated by the numeral 10'. A fuseholder 12 is mounted with its enlarged part 14 extending through the opening 16 in the mounting panel 18 and is secured in place by means of a U-shaped fastener clip 20 which is slid between raised portions 22 of the fuseholder on opposite sides thereof, one of said raised portions 22 being shown in enlarged detail in FIG. 2 and the interior face 24 of panel .18. Alternatively, a fastener clip 26 of the type shown in FIG. 3 or that shown in FIG. 3a may be employed.

The fastener shown in FIG. 3 is provided with tongues :28, 28a, which after the fastener is slid over the intermediate portion 14 in the direction of the arrows and into contact with the lower face 24 of the panel 18, engage said intermediate part and prevent the fastener from being removed, thus securing the fuseholder to the panel 18.

The fastener 30, shown in FIG. 3a, may be pre-assembled with fuseholder part 12 and inserted through hole '16 of panel 18, so that prongs 34 and 34a engage the outer face 32 of panel 18.

The horseshoe-shaped fastener 26 can be applied from the front or back of the fuseholder, depending on whether the fuseholder is mounted from the back of the panel 18 or from the front of the panel mounting hole. Front panel mounting makes the mounting fastener or clip 26 inaccessible; back panel mounting makes possible the wiring of the fuseholder before mounting, while not as much of the fuseholder protrudes from the ballast case. The fastener 20 is installed only on the back after insertion of the holder from the front.

The fastener with the spring catch lancings allows the original equipment manufacturer using the fuseholder to completely sub-assemble the clip and insert all wiring, thus rendering the final assembly in the ballast case quicker and easier.

After the fuseholder 12 has been secured in any one of the ways described above, the black lead 36 of the line, from the core and coil 38 is secured to one end terminal of the fuseholder 12, at 39', while another black lead 40 of the line is secured to the other end of the fuseholder 12, at '42 and is connected to an A.C. power source.

For the sake of clarity, a capacitor 44 is shown in phantom in the ballast unit 10.

The fuseholder 12 illustrated in the drawing is of the type described in the present applicants U.S. Patent No. 3,287,528 issued on Nov. 22, 1966. It is to be clearly understood, however, that the present inventive combination is not limited to the employment of this particular fuseholder, but that any other fuseholder permitting the replacement of a fuse may be used as part of the present combination, while the fuseholder proper is integral with the ballast unit.

An important feature of the invention is the prevention of a replacement of a burned out fuse with one of a wrong rating; thus the factory assembled fuse 46 of a predetermined rating with an integral cap 48 and insertable in the fuseholder 12, of the same rating is provided with a cap 50 formed with a pair of opposed flanges of predetermined unequal sizes 50a and 50b, which correspond only with the respective openings 54 and 56 of aperture 52 of said fuseholder 12, (-FIG. 8) also of a predetermined capacity.

Thus, the fuse rating for a particular ballast unit may be controlled and assured, since a fuseholder of a predetermined rating will receive only a fuse of the same rating.

Although the invention has been described with reference to the above embodiment i.e., with the fuseholder permanently mounted on the ballast case, the inventive concept is intended to apply to any integral holder for use with any serviceable protective device whether it be called a fuse, circuit breaker or by any other name.

Having thus described my invention, what I claim and desire to protect by Letters Patent of the United States of America is:

1. A fluorescent lamp ballast comprising:

(a) a housing having a mounting panel for a fuseholder,

(b) the mounting panel having an opening and having outer and inner faces,

(c) the fuseholder having an enlarged part extending through the panel opening inwardly of the housing,

(d) the enlarged part having raised portions,

(e) a fastener clip wedged between the raised portions and the inner face of the mounting panel securing the enlarged part to the mounting panel, and

(f) the fastener being a U-shaped flat member with leg portions formed with indented prong elements extending at right angles to the respective legs engaging the outer face of the mounting panel.

2. The device according to claim 1, wherein the fastener clip is an elliptical flat plate having an opening therein defined by an elliptical edge portion and a pair of spring catch lancings formed on a pair of the elliptical edge portions.

3. The device according to claim 1 wherein:

(a) the enlarged part of the fuseholder receives a fuse of predetermined rating having an integral cap formed with a pair of opposed flanges of substantially unequal sizes,

(b) the enlarged part of the fuseholder having recesses corresponding in size to the flanges, respectively, whereby the fuseholder of a predetermined rating will receive only a fuse of the same rating.

References Cited UNITED STATES PATENTS 1,940,176 12/1933 Marshall 200-442 2,444,522 7/1948 Nathanson 31715 2,956,210 1 0/1960 Yatsushiro 200 142 X 3,130,479 4/1964 Pleiss 29-1555 3,173,059 3/1965 Stake 317-15 3,275,774 9/1966 Miller 200-142 X 3,351,815 11/1967 Wolfert 317-15 X BERNARD A. GILHEANY, Primary Examiner.

H. B. GILSON, Assistant Examiner.

U.S. Cl. X.R. 337225

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