Title of Invention

A SCREWLESS LAMPHOLDER

Abstract

The present invention relates to an Screwless Lampholder particularly one piece metallic Lampholder comprising of one piece external metallic body and a hybrid two piece screwless insert, the one piece external metallic body having a pair of clips at diametrically opposite ends in the center being adapted to move in ward and outwards, a pair of integral screwless terminal is provided diametrically opposite to each other alongwith a pair of coil spring loaded plunger pipe, a pair of straight steps (locks) provided on the screwless insert being similar to and engage the clips when pressed in the inward to and engage the clips when pressed in the inward position and a pair of circular collars provided below the straight steps prevent the screwless insert to slip out of the one piece metallic body when the clips are pressed in the inward position.

Full Text

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to Screwless Lampholder. More particularly this invention relates to screwless insert to be used with one piece metallic Lampholder. Screwless Lampholder refers to the arrangement of securing the current carrying live & neutral conductors by push-in type of spring clamps which is a labor saving device for faster and economic mass production / assembly. Screwless Lampholder may or may not include earth connection. The earth connection, if required will be through screwed clamping of each crstute in the earth terminal screwed or riveted on the one piece external body. 2. Description of the Related Art In the Screwless Lampholder one piece, two piece, three piece in wholly plastic external body and with leaf spring operated contact plungers are known in the art. The main drawback of such leaf-spring type plungers are that these loose rapidly resiliency on repeated plunger compression, making these non conforming to ruling standards for such lampholder. The problems in providing Screwless facility in one piece metallic lampholders are mainly the constraint of space inside the external metal body of the lampholders. The creepage & clearance problems unsuitability of leaf-spring type plungers stringent operating conditions as per standard, at elevated temperatures, cost constraint, interchangeability for use with existing external body and adaptability for both stranded & boot-lace type conductors made its a daunting job for providing screwless facility in lampholders. 3. SUMMARY OF THE INVENTION To solve the above-described problems, it is an objective of the present invention to provide an one piece metallic Lampholder with screwless facility for securing the current carrying Live & Neutral conductors. The labor involved in wiring such lampholders are much less as compared to the conventional screw-type lampholders. Screwless Lampholder comprising of a one piece external metallic body and a hybrid two piece screwless insert characterized in that the one piece external metallic body is having a pair of clips at diametrically opposite ends in the center being adapted to move in ward and outwards, a pair of notches at diametrically opposite ends to engage grooves of screwless insert; the screwless insert assembly comprising of bakelite body provided with a pair of straight steps, nylon back-cover, two plunger pipes, two coil spring, screwless terminals. BRIEF DESCRIPTION OF THE DRAWINGS The above objective and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which: Figure 1.: Shows the front elevation view of the one piece Screwless lampholder & the assembled screwless insert. Figure 2. : Cross- Sectional view of the screwless lampholder. Figure 3 : Front elevation view of the Screwless Terminal. Figure 4 : Perspective view of the parts of the knocked down screw-less insert Figure 5 : Perspective view of the assembled screwless insert. DETAILED DESCRIPTION OF THE INVENTION As shown in the accompanying drawings the screwless lampholder according to the present invention consists of two parts, one part is called the external one-piece metallic body 1, shown in Fig. 1 & 2 and the other part is called the screwless insert unit 2, shown in Fig. 1 & 4.The external one piece metallic body has a pair of clips or U-cut 9, shown in fig. 1 provided at the diametrically opposite ends in the center. The clips are formed by punching out a U-shaped metal piece from the external one piece body at predetermined positions. The clips can be moved inward and outward to respectively hold or release the screwless insert 2, shown in fig.l & 4, a pair of dimples or notches 8, shown in fig. 1 are provided at diametrically opposite positions in the one piece body at predetermined positions and the said notches are adapted to engage the grooves or notches 14, shown in fig 5 are provided on the screwless insert 2. A pair of curved shaped punching or J-cuts 10, shown in fig.l are provided at two diametrically opposite position at the circular outer edge of the external one piece body and the said punches 10 are adapted to receive therein the outwardly projecting pins of an electric bulb when the bulb (not shown) is fitted in the lampholder. The internal threads 7, shown in fig 2 are provided at the inside of the upper end of the external one piece metallic body to hold the one piece lampholder in to the electric fittings where an electric fittings where an electric bulb has to be fitted i.e. ceilings fittings, wall fittings, chandeliers, pendants, flush fittings, spot lights and other decorative lights. The screwless insert consists of the Bakelite body 2 and nylon back-cover 3, both shown in fig.l. The Bakelite body 2 houses two plunger pipes 4, shown in fig.2 and two coil springs 5, shown in fig. 2 in the two circular housing 19, shown in fig. 5. The two coil springs rest on two especially built screwless terminals 6, shown in Fig. 3 and housed in two pockets 17, shown in fig. 4 of the Bakelite body 2. The coil springs sit on the brass strips of the screwless terminals 6. The assembly of pipes springs & screwless terminals are retained in position by the nylon Back-cover clipped on the Bakelite body, by the two legs 13 & 15, shown in fig.5 of the back-cover. A pair of holes 11, shown in fig.5 are provided in the Back-cover for insertion of conductors /wires into the screwless terminals. Another pair of rectangular Slots 12, shown in fig.5 are provided in the back-cover for release of the conductors /wire. The main feature of this Screwless invention is the miniature design of the screwless terminal which consists of the Brass strip 6 for making the current conducting path and the spring strip 6A, shown in fig.3, both brass strip & brass spring being riveted together for making an integral screwless Terminal. The special design of the screwless Terminals adapts both stranded and bootlace(crimped) wires, providing stopper for the conductor and also resting support for the coil springs 5. A pair of notches 14 corresponding to the notches 8 in the external one piece metallic body are provided on the Bakelite body 2. A pair of the straight steps 18 at diametrically opposite position corresponding to the position of clips are provided on the Bakelite body which are adapted to, receive the clips when pressed in the inward position. The circular collars below the steps do not allow the screwless insert to drop out of the external one piece metallic body when the clips 9 are pressed in the inward position. The stopper 16, shown in fig. 5 of the Bakelite body projects through the central slot of the Back-cover 3, provided back stopper of the screwless insert. The manufacturing is mostly done in presses. The metallic disc cut from the sheet coil passes through various known operations of pressing when a deep drawn shell come out. Later on by punching and by threading machines the one piece external metallic body is formed. The Bakelite body & the Nylon Back Cover are moulded from specially developed dies. Plunger pipes, springs & Screwless Terminals are made on lattes, press machines and other special purpose machines by known methods. The assembly of the Screwless Lampholder insert is done by placing the components in the sequence shown at Fig.4 and then clipping the back plate on the Bakelite. To dis-assemble, the Back-cover can easily by opened by inserting a screw-driver between the Back-cover legs and the vertical walls of the Bakelite Body is assembled position with the spring loaded plunger pipe facing outward, the Screwless Insert is moved inside the one piece metallic external body such that the Notches 14 provided on the Bakelite Body are engaged by the Notches 8 provided on the external body. Afterwards the clips 9 of the external body are moved inwards to hold the Screwless insert inside the lampholder. To wire the Screwless Lampholder, the clips are moved outward whereby the screwless insert gets released and come out of the one piece external body. The wiring is done with the Back-Cover of the insert facing upwards and pushing in either stranded / crimped conductor wires through the conductor holes 11 of the Back-plate till stopped by the brass strip 6 of the screwless Terminal. The conductors are then pulled slightly to ensure proper gripping of the conductors by the leaf spring 6 A against the vertical brass strip face 6 of the Screwless Terminal. For release of the conductor wire a pointed pin is inserted at an angle of 45° to back-cover face, through the wire release slots 12 of the Back plates and pressing the pin slightly downwards after insertion, so as to release the conductors form he grips of the leafs springs 6A of the Screwless Terminals. Then on pulling the conductors will come out of the inserts. After wiring the Screwless Terminal / Insert as described above, the Screwless Insert with spring loaded plunger pipes facing outwardly, is moved inside the external body and afterwards the clips 9 are pressed inwards. The Clips 9 when pressed in the inward position, do not allow the Screwless Insert to come out of the one piece external body. What is described and illustrated above should not in any way be construed as limiting the scope of this invention which may be subject to various modifications. We Claim: - 1. A Screwless Lampholder comprising of a one piece external metallic body(l) and a hybrid two piece screwless insert (2) characterized in that the one piece external metallic body(l) having a pair of clips(9) at diametrically opposite ends in the center being adapted to move in ward and outwards, a pair of notches (8) at diametrically opposite ends to engage grooves (14) of screwless insert; the screwless insert assembly comprising of bakelite body provided with a pair of straight steps, nylon back-cover(3), two plunger pipes(4), two coil spring(5), screwless terminals (6). 2 A Screwless Lampholder as claimed in claim 1, comprising a pair of Screwless Terminal diametrically opposite to each other, wherein said each Screwless Terminal is provided in the pocket of Screwless Insert. 3 A Screwless Lampholder as claimed in claim 1 or 2, wherein the Screwless Terminal comprises spring strip for conductor gripping . 4 A Screwless Lampholder as claimed in claim 1 or 2, wherein the Screwless Terminal comprises brass strip for current conducting. 5 A Screwless Lampholder as claimed in claim 1 or 2, wherein the Spring strip and brass strip are both riveted together. 6 A Screwless Lampholder as claimed in claim 1, having a coil spring loaded plunger assembly wherein plunger pipes are inserted in two pockets provided in bakelite body alongwith coil spring which sits on the brass strips of the Screwless Terminals; the said Nylon Back-cover being clipped on to the Bakelite Body. 7 A Screwless Lampholder substantially as described and as illustrated herein with reference to the accompanying drawings.

Documents:

882-del-1999-abstract.pdf

882-del-1999-claims.pdf

882-del-1999-correspondence-others.pdf

882-del-1999-correspondence-po.pdf

882-del-1999-description (complete).pdf

882-del-1999-drawings.pdf

882-del-1999-form-1.pdf

882-del-1999-form-19.pdf

882-del-1999-form-2.pdf

882-del-1999-form-3.pdf

882-del-1999-form-4.pdf

882-del-1999-form-5.pdf

882-del-1999-form-62.pdf