AU730468B2

AU730468B2 - Attachment arrangement for armoured handset cord

Info

Publication number: AU730468B2
Application number: AU23571/97A
Authority: AU
Inventors: Robert Ashley; Larry Ross James
Original assignee: Alcatel Australia Ltd
Current assignee: Nokia Services Ltd
Priority date: 1996-06-03
Filing date: 1997-05-22
Publication date: 2001-03-08
Anticipated expiration: 2017-05-22
Also published as: AU2357197A

Description

P/00/01i1 28/5/9 1 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "ATTACHMIENT ARRANGEMENT FOR ARMOURED HANDSET CORD" The following statement is a full description of this invention, including the best method of performig it known to us:- 2 This invention relates to tamper-proof pay telephones and in particular to an attachment arrangement for mechanically attaching an armoured handset cord assembly to a payphone housing.

For many years telecommunications authorities have used armoured handset cords for connecting the handset to a public payphone in order to minimize vandalism of the payphone.

A known armoured handset cord arrangement comprises an armoured sheath in the form of a flexible stainless steel hose within which is disposed a plurality of insulated electrical conductors and a strength member. The strength member is in the form of a stainless steel wire braided rope having a swaged end-termination on each :.910 end. The electrical conductors are to connect the handset's transmitter and receiver lOelements to circuitry in the payphone housing.

The end of the armoured handset cord remote from the handset is attached to a known hollow cylindrical attachment arrangement which is fixedly attached to the payphone housing and is provided with a co-axial passageway through which the .15 electrical conductors and an end of the strength member enter the payphone housing.

The strength member is disposed within the hollow cylindrical attachment and the handset case such that, if a large longitudinal force is applied to the handset, which would occur if a vandal attempted to rip the handset from the housing, the swaged end-terminations co-operate with shoulder members on the cylindrical 20 attachment and within the handset case to wedge the end-terminations and allow the o.*o strength member to absorb the stress.

A problem which can occur with the above known arrangement is that payphone vandals may twist the armoured sheath about its longitudinal axes, thereby twisting the electrical conductors therein which are terminated on terminals within the housing. This may cause the conductors to be damaged and thereby cause electrical faults in the payphone.

In order to prevent twisting of the cord to be transferred to the conductors, it is known to weld the armoured sheath to the hollow cylindrical attachment arrangement.

This is achieved by providing a radial hole in the side of the cylindrical attachment which communicates with the co-axial passageway, and welding through the basehole.

This welding step is relatively difficult and adds to the cost of the payphone.

It is an object of the present invention to provide an improved attachment arrangement for mechanically attaching an armoured handset cord of the aforementioned type to the housing of a payphone.

It is a further object of the present invention to provide an attachment arrangement for attaching an armoured handset cord of the aforementioned type to the housing of a payphone, said arrangement having simple means by which any twisting of the armoured sheath is prevented from being transferred to the electrical conductors within the armoured sheath.

According to the invention there is provided an attachment arrangement for attaching an armoured handset cord to a payphone housing, said handset cord being of the type comprising an armoured sheath enveloping a plurality of electrical conductors and a strength member terminating in a swaged end terminations, said attachment arrangement comprising a cylindrical member provided with a co-axial passage for receiving an end of said handset cord remote from said handset, said "15 cylindrical member comprising a base section, an intermediate section having an 00°* •open cavity communicating with said passage for leading therethrough said electrical conductors, and means for fixedly mounting said arrangement onto a wall of said payphone housing, and a hollow top section defined by an open top, a partially closed bottom wall and a side wall interrupted by a slit for receiving an end part of 'i20 said strength member, wherein said intermediate section is provided with a pair of .o 0 transverse slots in its side wall of a predetermined depth to form respective apertures each of which communicate with said passage, said slots forming a keyway for slidably receiving respective limbs of a planar bifurcated key member, said limbs deforming parts of said armoured sheath that are adjacent said apertures when said key member is inserted into said keyway.

In order that the invention may be readily carried into effect, an embodiment thereof will now be described in relation to the accompanying drawings, in which: Figure 1 shows a perspective view of the attachment arrangement of the present invention including a disengaged locking key member.

Figure 2 shows the attachment arrangement of Figure 1 with the locking key member engaged.

Figure 3 shows a side view of the attachment arrangement fixed to a wall of a payphone housing.

Figure 4 shows a perspective of the attachment arrangement coupled to an armoured handset cord.

Referring to Figure 1 3, the attachment member 1 comprises a hollow stainless steel cylindrical tube 65 mm in length having a base section 2, an intermediate section 3 and an end section 4. The outer diameter of the intermediate section and end section are incrementally reduced relative to the outer diameter of the base section which is 17 mm.

Intermediate section 3 comprises an open hemicylindrical section 5 exposing the co-axial passageway 6 defined by the walls of base section 2 and intermediate section 3, and a pair of transverse slots 7 and 8, the depth of the slots being such that each slot communicates with passageway 6. Slots 7 and 8 form a keyway for slidably o. receiving respective limbs 9 and 10 of a planar bifurcated stainless steel key member 11. The gap defined by the inner surfaces 12 of slots 7 and 8 being such that upon 15 insertion of key member 11 into the keyway the inner surfaces 12 slidably abut the bottom wall 13 of the slots. The width of the gap between the inner surfaces 12 is less than the diameter of passageway 6 whose diameter is such that it just slidably accommodates the diameter of an armoured handset cord. Intermediate section 3 also includes a circumferential groove 14 and a connecting portion 15 which connects 0 20 the intermediate section to the base section the top of which forms a first shoulder 16.

.oo SIThe bottom surface of base section 3 (not shown) is a concave annulus. The cylindrical side wall of base section 3 is interrupted by a flat section 17 which allows the attachment member to be mounted close to a side wall of a payphone housing if required.

Top section 4 comprises a hollow cylinder having an open top and a partially closed bottom surface 18. The cylinder is split by a single slit 19 which also partially slits the bottom surface 18 to allow the interior of section 4 to communicate with the open hemicylindrical section 5 of intermediate section 3. The width of slit 19 is such as to permit the braided cord of the armoured cord's strength member to pass through.

Referring to Figure 4, in use an end, remote from a handset (not shown) of a known armoured handset cord 20, together with four electrical conductors 21 and a strength member 22 of a predetermined length, typically 60 mm, and terminating in a swaged terminating end 23, are fed through passageway 6 from the base section until the end of the outer armoured sheath is just below the open hemicylindrical section at which point opposite portions of the armoured sheath are adjacent and exposed by respective slots 7 and 8. The electrical conductors are led out from the open hemicylindrical section 5 to be terminated, and the length of strength member 22 is pushed into slit 19 and located above the open top of top section 4.

Key member 11 is inserted into the keyway formed by slots 7 and 8 as shown in Figure 2. As a result the opposite portions of the circular armoured sheath adjacent 0 and exposed to slots 7 and 8 are compressed and deform this portion of the armoured sheath into a generally elliptical shape, thereby preventing any twisting of the armoured cord from twisting the electrical conductors 21.

In the event of a large longitudinal force being applied to the handset cord the swaged end termination 23 moves downward into the hollow interior of top section 4 15 and abuts the bottom surface 18 thereof and absorbs the stress.

o*

Claims

1. An attachment arrangement for attaching an armoured handset cord to a payphone housing, said handset cord being of the type comprising an armoured sheath enveloping a plurality of electrical conductors and a strength member terminating in a swaged end termination, said attachment arrangement comprising a cylindrical member provided with a co-axial passage for receiving an end of said handset cord remote from said handset, said cylindrical member comprising a base section, an intermediate section having an open cavity communicating with said passage for leading therethrough said electrical conductors, and means for fixedly mounting said arrangement onto a wall of said payphone housing, and a hollow top section defined by an open top, a partially closed bottom wall and a side wall interrupted by a slit for receiving an end part of said strength member, wherein said intermediate section is provided with a pair of transverse slots in its side wall of a predetermined depth to form respective apertures each of which communicate with said passage, said slots forming a keyway for slidably receiving respective limbs of a planar bifurcated key member, said limbs deforming and wedging parts of said armoured sheath that are adjacent said apertures when said key member is inserted into said keyway, thereby preventing rotation of said sheath and said electrical conductors therein.

2. An arrangement as claimed in claim 1, wherein the outer diameter of the intermediate section and the end section are incrementaly reduced relative to the outer diameter of the base section.

3. An arrangement as claimed in claim 1 or 2, wherein said open cavity in said intermediate section is formed by a hemicylindrical section of said intermediate 25 section.

4. An arrangement as claimed in any one of claims 1 3, wherein said means for fixedly mounting said arrangement onto a wall of said payphone housing comprise a circumferential groove in said intermediate section for co-operating with a clip arrangement and a connecting section connecting said groove to said base section. 7 An arrangement as claimed in any one of the preceding claims, wherein the wall of said base section remote from said hollow top section is a concave annulus.

6. An arrangement as claimed in any one of the preceding claims, wherein said base section's side wall is interrupted by a flat section.,

7. An arrangement as claimed in any one of the preceding claims wherein said cylindrical member is made of stainless steel.

8. An arrangement substantially as herein described with reference to Figures 1 4 of the accompanying drawings. DATED THIS FIFTEENTH DAY OF DECEMBER 2000 ALCATEL AUSTRALIA LIMITED 000 005 363)