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(11) | EP 0 467 866 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Connection for lamp bulbs for use in control and signal panels, with quick mounting contacts |
| (57) The connection comprises in an insulating block, for each connection: two through
seatings having parallel slots, with support and retaining shoulders; in each of said
two seatings an elongated strip-like metallic component (20) forming two oppositely
situated elastic contacts (42) admitting the cap of the light bulb, support and retaining
ledges (32, 36) adapted to cooperate with said shoulders, one (36) of which ledges
is elastic, for anchoring the component (20) in the seating, and, at the end opposite
to that with the elastic contacts (42), a current connection terminal (26, 28), offset
relative to the centre line of the component (20), for one of the two supply conductors
of the two components. |
[0001] The invention relates to a system for the fast connection of lamp bulbs, particularly of the type used in control and signal installation panels.
[0002] Among the aims and advantages of the invention - which will become apparent on perusal of the following text - mention may in particular be made of the simplicity and standardization of the metallic components of the contacts, the ease of assembly on an insulating support for a multiplicity of lamp seatings, the simplicity of construction of said insulating support, and others.
[0003] The connection system according to the invention substantially comprises: in an insulating block, for each connection, two through seatings having parallel slots with support and retaining shoulders; in each of said two seatings an elongated strip-like metallic component forming two oppositely situated elastic contacts admitting the cap of the lamp bulb, support and retaining ledges for anchoring in the seating and, at the end opposite to that with the elastic contacts, a current connection terminal, offset relative to the centre line of the component, for one of the two supply conductors of the two components.
[0005] The invention will be better understood on examination of the description and the accompanying drawing, which illustrates one non-limitative practical exemplification of said invention and in which:
Figure 1 shows a general diagram in front view of a panel consisting of an insulating block having a plurality of seatings for lamp bulbs;
Figure 2 shows a section on the line II-II in Figure 1, without the metallic components of the contacts being installed;
Figure 3 is similar to Figure 2, but shows one of the seatings equipped with the metallic contacts and with the lamp bulb;
Figure 4 is a section on the line IV-IV in Figure 1, showing the means of securing the insulating panel block to a support;
Figure 5 shows a section on the line V-V in Figure 1;
Figures 6 and 7 show an elongated strip-like metallic component forming one of the contacts for the lamp bulb, in two opposite views in perspective;
Figures 8, 9 and 10 show an enlarged detail of Figure 6, a front view of said detail and a section on the line X-X in Figure 9;
Figure 11 shows in perspective the relative positions of the two elongated strip-like metallic contacts and of the lamp bulb mounted in them, and
Figure 12 shows separately in perspective the lamp bulb to be used for the connection in question.
[0006] As illustrated in the accompanying drawing, 1 indicates an insulating block which can constitute a panel for forming a plurality of seatings for lamp bulbs; according to Figure 1 the block comprises three rows of seatings in alignment with one another, the seatings of each row being fitted with connections, that is to say lampholders, which are to be fed by two linear conductors parallel to one another.
[0007] Each of the seatings formed by the block 1 has a pair of slots 3 separated by a diaphragm 5 and differently profiled; in particular, each slot 3 is provided with a stop shoulder designated 9 for supporting in one direction the metallic component which it is to receive; the partition 5 has a support shoulder 10 to serve as a stop for the light bulb. In addition, side shoulders 12 are provided (preferably formed during the stamping to correspond to other slots 13 starting from the opposite end of the panel 1 to that where the lamp bulbs L are inserted) in order to prevent the detachment of the metallic component inserted into the seating. The panel 1 has teeth 14 for snap connection to support means, such as those generically designated 16 (Figure 4).
[0008] Each of the seatings comprising slots 3 receives a strip-like metallic component 20 (see in particular Figures 6 and 7), which consists of a single metallic strip cut and stamped to the required shape. Each component 20 has an elongated flat strip-like part 22 whose longitudinal edges 24 are flanged over to form a cross-section of a size corresponding to that of the cross-section of the corresponding slot 3, so that the component can be inserted into the slot 3 in a fairly stable manner. At one end the strip is provided, offset in relation to the axis of symmetry of the component 20 (see also Figures 8 to 10), with a relatively narrow tail 26, which is extended and folded over to form two juxtaposed thicknesses 26A and 26B. The thickness 26B has a relatively wide slot 28B, and correspondingly the thickness 26A has a relatively narrower slot 28A (or vice versa); both the slots start with a widened inlet 28C provided in both the thicknesses in a position corresponding to the zone in which the tail 26 is folded over. With this arrangement, when a sheathed cable C is inserted into the slots it is centered by the slot 28B, the width of which corresponds substantially to the diameter of the sheath, while the edges of the narrower slot 28A cut into the sheath and come into contact with the metallic conductor M of said cable C, thus forming a supply connection of the so-called current stealer type for contact with the strip-like component 20; this arrangement is particularly illustrated in Figures 8, 9 and 10.
[0009] The flat part 22 of the component 20 is provided at the top with a transverse step-like bend 30 which projects from the flat part 22 on the same side as the flanged longitudinal edges 24; in a position corresponding to said step 30 a window 32 is formed which by its transverse edge forms a support ledge for the strip-like component, in a position corresponding to a flat zone 34 of said component, separated from the flat zone 22 precisely by the step 30. In positions corresponding to the flat zone 34 two small tongues 36 are formed by cutting and deformation so as to constitute admission stops for the purposes indicated below; the longitudinal edges of the flat zone 34 are flanged over as shown at 38, on the opposite side to the flanged edges 24. From the flanged-over longitudinal edges 38 two opposite support appendices 40, folded over inwards, are formed for the purposes indicated below. From the bottom ends of the longitudinal edges 38 two symmetrical admission springs 42 extend and are bent over, flanking the flat zone 34 and forming, in positions approximately corresponding to the support appendices 40, two corners relatively close to one another, then ending in an admission part for the purposes indicated below of coupling to the cap of the light bulb L. The material of the admission springs 42 is taken from the same strip from which the component 20 is formed, on the outside of the material of the edges 24.
[0010] The two strip-like metallic components 20 intended to form the seating for the connection of a lamp bulb L are inserted into the slots 3 in such a manner that the edges 38 take up positions one facing the other in a relatively widened zone which is defined between the two parts 34 of said components for the purpose of receiving the lamp bulb L; on the other hand, the longitudinal edges 24 are turned outwards in relation to the central symmetry diaphragm 5. The insertion of the two components 20 into the slots 3, in the direction of the arrows f20 in Figure 3, is limited by the supporting of the transverse edge of the window 32 of each component against the respective shoulder 9. On insertion the inclined tongues 36 are received with an elastic snap action against the respective shoulders 12 in such a manner as to prevent the possible detaching of the metallic components 20 in the opposite direction to the arrow f20. In the interspace between the two zones 34 of the two components 20 received in the two slots 3 the two pairs of angular-admission springs 42 are situated, their deformation in the direction away from one another being limited in each case by the encounter with the respective appendix 40.
[0011] The cap Z (see Figure 12) of the light bulb L can be inserted into said interspace between the two flat zones 34. On each side the cap Z has a longitudinal sliding contact Z1 and on the opposite side a retaining cavity Z2. On insertion between the two flat zones 34 of the components 20 which form the seating for the cap Z, one of each pair of springs 42 comes into contact with the sliding contact Z1, while the other slides on the cap until, when the insertion has been completed, it penetrates by its corner zone into the cavity Z2, thus having the effect of retaining the light bulb L; thus, two of the diagonally opposite springs 42 cooperate with the cavities Z2, while the other two diagonally opposite springs cooperate with the sliding contacts Z1, thereby ensuring on the one hand the retention of the lamp bulb and on the other hand electrical contact with the two components received in the slots 3. The lamp bulb is inserted as far as a limit, which can be established by the ledge 10 formed by the diaphragm 5, while the stability of the position of the strip-like metallic components 20 in the seatings for the cap Z is achieved on the one hand by means of the ledge formed by the window 32 and on the other hand through the retaining action achieved by the tongues 36.
[0012] It is clear that the mounting of a combination of connections in a panel or block 1 is extremely easy, all that is required in practice being the insertion of the parts 22 into the slots 3 in the direction of the arrows f20 so as to achieve a stabilized position of the components 20, with the tails 26 forming terminals projecting at the other end to that where the seatings for the lamp bulbs L are formed. The lamp bulbs L can be easily inserted and extracted, simply by overcoming the resistance offered by the admission springs 42 to movement apart; incorrect insertion or attempted excessive deformation of the springs 42 is prevented by the stop action of the appendices 40 prohibiting deformation of the springs 42 beyond a certain predetermined limit. Wiring is simply effected by inserting the cable C into the slots 28C, 28B, 28A, with automatic metallic contact made by the edges 28A; the cables are disposed in a rectilinear arrangement for all the connections situated in the same alignment.
[0013] With the arrangement described a number of advantages are achieved, as already mentioned in the preamble, consisting of the convenience of construction and assembly of the various components, the greatly simplified wiring, and also the safety and stability of the connections of the individual lamp bulbs, as well as the modular nature of the system, which permits even partial utilization and a single type of metallic component for all functions. Moreover, every contact is direct from cable to lamp bulb.
[0014] It is understood that the drawing shows only an exemplification given solely as a practical demonstration of the invention, and that the latter may vary in form and arrangement without thereby departing from the scope of the concept underlying said invention. The possible presence of reference numbers in the accompanying claims serves to facilitate the reading of the latter with reference to the description and to the drawing and does not limit the scope of the protection provided by the claims.
1. A connection for lamp bulbs, particularly of the so-called "WEDGE" type used in
control and signal installation panels, characterized in that it comprises: in an
insulating block (1), for each connection, two through seatings (3) having parallel
slots, with support and retaining shoulders (9, 12); in each of said two seatings
an elongated strip-like metallic component (20) forming two oppositely situated elastic
contacts (42) admitting the cap of the lamp bulb, support and retaining ledges (32,
36) for anchoring the component (20) in the seating and, at the end opposite to that
with the elastic contacts (42), a current connection terminal (26), offset relative
to the centre line of the component (20), for one of the two supply conductors of
the two components.
2. Connection for lamp bulbs according to the preceding claim, characterized in that
each of the strip-like components (20) has two longitudinal edges (24) flanged over
to form the guide section in the respective slotted seating (3), a transverse step
(30) provided with a window (32) to create a support ledge, and tongues (36) deformed
as admission retaining ledges to prevent detachment, said ledges cooperating with
respective shoulders (9, 12) obtained by stamping in the insulating block (1).
3. Connection for lamp bulbs according to Claim 1 or 2, characterized in that in two
oppositely situated portions (34), flanged-over longitudinal edges (38) of each strip-like
component form two angular-admission springs (42) for cooperation with a corresponding
sliding contact (Z1) and with a corresponding opposite cavity (Z2) retaining the cap
(Z) of the lamp bulb.
4. Connection according to Claim 3, characterized in that behind said angular-admission
springs (42), support appendices (40) are formed which are adapted to limit the deformation
of said angular-admission springs (42).
5. Connection according to Claims 1 and 2, characterized in that said transverse steps
(30) are disposed symmetrically in the two strip-like components arranged for a lamp
bulb and define a widened seating for the cap (Z) of said lamp bulb, with which the
four angular-admission springs (42) cooperate.
6. Connection according to the preceding claims, characterized in that each current
connection terminal is formed by a folded-over tail (26) with a wider slot (28B) in
one of the two thicknesses of said tail, in order to define the position of the sheathed
cable (C), and with a narrower slot (28A) in the other of the two thicknesses in order
to cut into the sheath and make contact with the conductor; the folded-over tail (26)
being offset relative to the centre line, so that in a row of seatings two rows of
aligned terminals are formed to receive current from two parallel cables.
7. Connection for lamp bulbs for use in control and signal panels, with quick-mounting
contacts; the whole as described above and illustrated as exemplification in the accompanying
drawing.