ELECTRICAL CONNECTION ASSEMBLY FOR RAIL MOUNTED DISPLAY

Abstract: An electronic labelling assembly (2) has a bus rail (4) extruded from an insulative material and having solid wire conductors (16, 18) embedded along a base wall (10) of the rail. Electronic labels (6) can be latched to the rail, by simply pressing them into the rail. Removal however requires a special tool (8) that has extensions (69) for biasing the latches out of engagement, and extension (66) for engaging a label release latch for lifting the label out of the rail.

Description: ELECTRICAL CONNECTION ASSEMBLY FOR RAIL MOUNTED DISPLAY This invention relates to an electrical connection assembly for mounting electronic displays or labels on a bus rail supplying electrical power or signals thereto. It is known to provide electronic retail price indicators, for example as described in US Patent 4,500,880. Typically, a price indicator tag or label comprises a PCB with electronic components, located within an insulative housing, and a display such as an LCD display. The electronic price label is clipped to a rail which may be provided with conductors for supplying power or electronic data signals to the label. As the position of articles on retail shelves are often rearranged, the position of corresponding electronic labels are also rearranged. There is therefore a requirement for electronic labels to withstand a relatively high number of plugging and unplugging cycles from the bus rails, whilst nevertheless insuring reliable electrical interconnection. A further problem with electronic labels is vandalism, whereby it would be desirable to render electronic labels more difficult to remove from their bus rails. It would also be desirable to reduce the exposure of electronic labels from accidental damage, for example due to collision with external objects. It would also be desirable to provide to provide electronic labels that are compact and that have an aesthetic appeal. Despite the need for secure labels, it would be desirable to enable rapid mounting and unmounting of labels from the bus rails, such that repositioning or replacement thereof can be quickly and easily effected by store personnel. It is an object of this invention to provide a secure yet easy to handle connection and mounting assembly for electronic labels on bus rails. Objects of this invention have been achieved by providing the connection assembly according to claim 1. Disclosed herein is a connection assembly comprising an electronic label and a bus rail on which the label is mountable, the electronic label comprising a housing and electrical terminals for interconnecting electronic components within the housing to bus conductors external of the housing, the label having latch members for engaging complementary latch members of the bus rail for latching of the label thereto, the bus rail comprising an insulative base supporting conductors for connection to the label terminals, the conductors extending substantially parallel to a longitudinal direction of the rail, wherein the label comprises a disengagement latch member to couple with a complementary disengagement latch member of a removable tool during release of the rail latch members by engagement of removal portions of the removal tool therebetween. The rail may be extruded from a plastic material wherein the bus conductors are solid wires embedded partially in the extrusion such that a cost effective manufacturing of the rail is possible. The solid wire conductors are exposed partially for abutment of resilient conducts of the label thereagainst . The solid wire conductors enable many plugging and unplugging connections without affecting the quality of the electrical connection between the contacts and the conductors. The label may be provided substantially flush or below outermost top and bottom edges of the rail that extend parallel to the longitudinal direction either side of the label, such that access to the rail by external objects is difficult. A well protected electronic label is thus provided. The latch members of the connection assembly may comprise a resilient latch or lip extending along the top or bottom edge of the rail for engaging substantially rigid locking shoulders of the electronic label. A front face of the label may be provided with cut-outs at the position of the locking shoulders such that an extension of the removal tool may be inserted therethrough and bias the resilient latch away from the locking shoulder for removal of the label therefrom. A further extension of the removal tool may be provided with a locking shoulder that engages a resilient latch of the label such that the label can be lifted off the rail upon unlatching therefrom. The removal latching shoulder of the tool may also be provided on an extension that is received through a cut-out through a front face of the label housing for increased security. The tool thus enables rapid unlatching of the label from the bus rails, but enhances security, especially due to the need for the special tool in order to remove the label from the bus rail. The electronic labels can be rapidly positioned at any position along the rails by merely clicking the label into latching position along the rail. Further advantageous aspects of this invention are described in the claims, or will be apparent from the following description and drawings. An embodiment of this invention will now be described by way of example with reference to the figures in which: Figure 1 is an exploded isometric view of a connection assembly according to this invention; Figure 2 is an isometric view of the connection assembly; Figure 3 is an isometric view of a removal tool of the connection assembly; Figure 4 is an isometric view of the connection assembly with a removal tool inserted in the label for removal thereof; Figure 5 is an isometric view towards a back or mounting face of a label with a removal tool; Figure 6 is cross .-sectional view through a center of a label mounted on a bus rail and receiving a removal tool; Figures 7-11 are successive side views of a label latched to a bus rail, the Figures showing removal of the label from the rail with a removal tool; Figure 12 is an isometric view of the connection assembly showing end portions of bus rails interconnected together; Figure 13 is a cross-sectional view through a rail end connection assembly; Figure 14 is an isometric view of the rail end connection assembly of Figure 13 Figures 15 and 16 are different isomeric views of a pair of rail end connections assemblies interconnected together . Referring to figures 1-6 a connection assembly 2 comprises a bus rail 4, an electronic label 6, and a removal tool 8. The electronic label 6 is shown without printed circuit board, electrical components, or a display, for more clarity. The bus rail 4 extends prismatically in a longitudinal direction L and in this embodiment is extruded from an insulative plastic material having some resiliency. The body 9 of the rail comprises a base wall 10, and top and bottom walls 12, 14 respectively upstanding and extending along top and bottom edges 13, 15 of the substantially planar base wall 10. Extending parallel to the longitudinal direction L are a pair of solid wire conductors 16, 18, one of the wire conductors 16 proximate the top edge 13 and the other 18 proximate the bottom edge 15, each wire conductor partially embedded in the base wall 10. The wire conductors 16, 18 have an exposed conductive surface 20 for receiving terminals of the label 6 in abutment thereagainst . The solid conducting wires 16, 18 may be embedded in the rail support 9 during the extrusion process such that a cost effective manufacturing of the bus rail is provided. The conductors 16, 18 may be substantially cylindrical in shape, whereby lips 22 flank the conductor around a circumference greater than 180 degrees such that the conductor is securely held to the base 10. It is also possible to provide conductors of other cross-sectional profiles, for example rectangular or polygonal profiles, although cylindrical wires are likely to be more cost effective. The bus rail 4 further comprises a continuous wall portion 24 in the form an L-shaped prism integrally extending from the top wall 12 having a branch 25 extending substantially parallel to the top wall 12 and separated by a gap therefrom. The wall portion 24, which may be flexible, forms a continuous latch having a latching shoulder 26 for engaging corresponding latching shoulders (see figure 1) 28 provided on substantially rigid protrusions 30 along a top or bottom wall 30, 32 of the label 6. The rail 4 may be provided with a flexible latch 24 integrally attached to the bottom wall 14 in a similar or identical manner to the top wall 12. The symmetry would enable the label 6 to be positioned the right way up irrespective of the orientation of assembly of the rail to a shelve. The label 6 comprises an insulative housing 36 comprising a base 37 and cover 38 latchable to the base 37 by means of interengaging latches 39, 40. The base and cover parts enclose a cavity 42 within which is received a printed circuit board with electronic components (not shown) for processing data signals and feeding information to a display, such as a liquid crystal display positioned at a cut-out 44 through a front face 46 of the cover 38 (the display is not shown) . A pair of terminals 48 are provided below the printed circuit board mounted to a mounting section 49 of the base 37. The terminals 48 have PCB contact protrusions 50 for resilient abutment against circuit traces of the PCB, and contact portions 52 for abutment against the conductors 16, 18, the contact portions 52 resiliently biasable through slots 54 in the base wall 47. The terminals 48 in this embodiment are edge stamped from sheet metal into substantially U-shapes wherein one cantilever branch 56 of the U comprises the contact protrusion 50, and the other branch 58 comprises the conductor contact portion 52, the contact protrusion/portion proximate free ends of the branches 56, 58 respectively. The housing slot 54 also acts as a guide for laterally guiding the contact portion 52, such that it biases substantially within the plane of the sheet metal. A particularly simple and cost effective terminal is thus provided, whereby the edge stamping and U-shaped configuration of the integrally formed branches 56, 58 allow a particularly compact terminal with high contact force. A pair of terminals 48 may be provided in opposed orientations as best seen in Figure 1 such that the contact portions 52 contact the two conductors, 16, 18 respectively. Projecting below the base wall 47 as best seen in Figure 5, are anti-overstress studs 60 engageable against the base 10 of the rail 4 when the label 6 is pressed thereagainst in order to limit deformation of the terminal contact branch 58; in other words by limiting depression of the conductor contact protrusion 52 into the housing 36. The anti-overstress protrusion also protects the contact protrusions 52 from damage by external objects when the label is not mounted on the rail. As best seen in figure 6, the label housing 36, and in particular the cover 38 comprises a resilient latch member 62 positioned between the pair of the latching shoulders 28 (as best seen in Figure 1) for engaging a complementary latching member in form of a latching shoulder 64 (see figures 3 and 6) provided in a recess 65 of an extension 66 of the removal tool 8. A cut-out 68 is provided through the cover 38 for allowing the removal extension 66 to pass therethrough and access the removal latch 62. On the removal tool 8, either side of the central removal extension 66, are release extensions 69 for wedging between the rail latching arm 24 and the label housing such that the latching arm 24 is biased out of engagement with the housing latching shoulders 28, thereby enabling separation of the label from the bus rail. Cut-outs 70 are provided through the cover 38 in alignment with the locking shoulders 28 to enable passage of the tool release extensions 68 therethrough. The release extensions 69 may further be provided with oblique camming surfaces 72 for engaging corresponding oblique camming surfaces 74 (see Figure 1) of the base and cover latches in order to assist separation of the cover from the base with the tool 8. A single tool can thus be provided either for removing the label from the bus rail, or removing the cover 38 from the base 37 in the event disassembly of the label is required. Referring to figures 7-11, assembly and disassembly of the label 2 to the bus rail will be further described. As shown in Figure 7, the label 6 can be simply snap- fitted into the rail 4 whereby the label latching shoulders 28 engage the latch members 24 of the rail. The terminal contact portions 52 resiliently bias against the embedded wire conductors 20. The label housing, particularly the cover part, may be provided with ledges 76, 78 that rest against a recessed ledge 80 of the rail, whereby the label top face 46 is at or below the top edge 84 of the rail top and bottom walls 12, 14 respectively. The label is thus well protected, compact and relatively difficult to access. The solid conductors 20 are resistant to wear in comparison to thin film conductors sometimes used in bus rails. As seen in Figure 8, the elasticity of the latch arm 24 may also primarily come from outward resilient bending of the top, respectively bottom wall 12, 14 rather than from the latch wall portion 24, or from a combination of both. As can be seen in Figures 8 and 9, the release extensions 69 of the removal tool 8 are inserted until abutment with the latching shoulders 28 whereby the rail latching member 24 is biased out of engagement with the label latching shoulder 28. Simultaneously, the removal latch shoulder 64 engages the housing resilient removal latch 62 as shown in Figure 6 such that the label can be pivotly lifted out of the rail as shown in Figure 10. The removal tool 8 is released from the label 6 by pivoting the removal extension 56 out of engagement with the removal latch 62 and subsequently extracting the removal tool 8 from the corresponding cut-outs 68, 70 of the label housing as depicted in Figure 11. Referring to Figure 12, sections of rail 4, 4' can be interconnected together by termination connectors 86, 86' that are provided with a housing 87 (see Figure 13) comprising base and cover parts 88, 89 and a pair terminals 48 that are identical in construction to the terminals of the label 6, and are mounted to the base in a similar manner. A cable 90 having insulated conducting wires therein interconnects a pair of termination connectors 86, 86' that are mounted at ends of the bus rail sections 4, 4' . The conductors of the cable 90 may be terminated directly to the terminals 48 by being stuffed into insulation displacing contact (IDC) slots 93 edge stamped out of the terminals 48. The conducting wires may be stuffed into the IDC slots 93 by means of the cover 89 provided with abutment or pressing portions 95 that stuff the wires into the IDC lots 93. Rapid and simple connection of the cable 90 to the conductors of the bus rail is thus achieved, whilst using the same terminals 48 as that of the label for cost-effective manufacturing. The cover 89 is provided with an end wall 96 for covering and insulating the end 91 of the rail section 4, 4' . The cover is symmetrically designed such that a single cover 96 can be mounted with the end wall 96 on either of the opposed sides of the base 88, such that as shown in Figure 16 the same base and cover are used to provide the mirror image termination connectors 86, 86' . The cable 90 may also extend to a control or power supply box for supplying the bus rails and labels with power and signals. Advantageously therefore, a secure electronic labelling system is provided that is well protected and difficult to remove without the aid of special tools. In addition, a robust electronic display system is provided enabling multiple plugging and unplugging whilst ensuring reliable electrical connection.

Claims: CLAIMS 1. A connection assembly (2) comprising an electronic label (6) and a bus rail (4) on which the label (6) is mountable, the electronic label (6) comprising a housing (36) and electrical terminals (48) for interconnecting electronic components within the housing to bus conductors (16, 18) external of the housing, the label having latch members (28) for engaging complementary latch members (24) of the bus rail for latching of the label thereto, the bus rail comprising an insulative base (10) supporting the bus conductors (16, 18) for connection to the label terminals (48), the conductors extending substantially parallel to a longitudinal direction (L) of the rail, characterised in that the label comprises a disengagement latch member (62) to couple with a complementary disengagement latch member (64) of a removal tool (8) during release of the rail latch members (24) from the label latch members (28) by engagement of removal portions (69) of the removal tool therebetween. 2. The connection assembly of claim 1 wherein a front face (46) of the label, from which an electronic display is visible, comprises cut-outs (70, 68) to enable extensions (66, 69) of the removal tool that comprise the complementary disengagement latch member (64) and removal portions (69) respectively, to pass therethrough for access to the disengagement latch member (62) and rail latch member (24) respectively. 3. The connection assembly of claim 2 wherein the disengagement latch member (62) of the label is resilient and has a latching shoulder engaging a latching shoulder (64) of the removal tool provided within in a recess (65) on a release extension (66) of the removal tool. 4. The assembly of claim 2 or 3 wherein the complementary disengagement latch member (64) of the removal tool is positioned centrally and spaced apart between the removal portions (69) of the tool. 5. The connection assembly of any one of the preceding claims wherein the bus rail is symmetrical about a longitudinal axis such that the label (6) may be clipped thereto in opposed 180 degrees orientations. 6. The connection assembly of any one of the preceding claims wherein the bus conductors (16, 18) are solid wires embedded in the insulative base (10), the insulative base being extruded, and the conductors embedded in the base during extrusion thereof. 7. The connection assembly of any one of the preceding claims wherein the label latch members (28) are substantially rigid, whereby resiliency is provided by the latch members (24) and/or side walls (12, 14) of the rail to which the latch members (24) are integrally formed. 8. The connection assembly of any one of the preceding claims wherein the bus rail latch members (24) and base (10) are integrally extruded to form a substantially prismatic form extending in the longitudinal direction (L) . 9. The connection assembly of any one of the preceding claims wherein the bus rail has top and bottom wall portions (12, 14) extending upwardly from the base (10) to free outermost edges (84) whereby the label (6) is mounted substantially flush or below the edges (84) for protection thereof. 10. The connection assembly of any one of the preceding claims wherein the label comprises edge-stamped terminals (48) comprising a U-shape with a first resilient branch (56) having a contact protrusion (50) for biasing against a printed circuit board mounted in the label, and a second branch (58) having a contact portion (52) for biasing against the bus conductor (16, 18), the contact portion (52) extending through a slot (54) in a base wall (47) of the label housing (36) .

Inventors: HUIN THIERRY, VOGEL FREDERIC, HUIN, THIERRY, VOGEL, FREDERIC
Applicants: HUIN THIERRY, VOGEL FREDERIC, WHITAKER CORP, HUIN, THIERRY, THE WHITAKER CORPORATION, VOGEL, FREDERIC
Application year: 1998
Main classification: H01R25
IPC codes: G09F9