Insulation displacement connectors

There are disclosed improvements for an electrical connector comprising a terminal for an insulative housing, electroconductive means disposed at least partly in such housing and having a portion connectable to a wire, a cap initially seatable in an up position on said housing, and adapted to be forcibly pushed down from said up position to a down position on said housing, and means permitting insertion of said lead into the space enclosed by such housing and cap and for effecting connection in said space of said inserted lead with said electroconductive means. The improvements are providing (1) in the same connector multiple terminals of the sort just described, (2) an arrangement which latches the cap from being detached from the housing in response to application to the terminal solely of lifting force on the cap, but which permits selective releasing of the cap in response to a force exerted by hand in the direction other than that of such lifting force, (3) strain relief for isolating the mentioned connection from pulling force on the lead.

FIELD OF THE INVENTION 
This invention relates generally to connectors for making an electrical 
connection between each of one or more insulated wire leads and each of 
one or more other insulated or uninsulated wires. More particularly, this 
invention relates to connectors of such kind which do not require the use 
of any tool to make such connection, and which are insulative displacement 
connectors in the sense that they comprise an insulative base and 
insulative housing and are operable to make such connection by relative 
displacement of these two insulative elements. 
BACKGROUND OF THE INVENTION 
U.S. Pat. No. 4,913,659 issued Apr. 3, 1990, in the name of Clarence E. 
Doyle for "Push Cap Terminals and Terminal Boards with Same" (the Doyle 
patent) discloses an electrical connector comprising a terminal for an 
insulated wire lead comprising an upstanding insulative housing, 
electroconductive means disposed at least partly in such housing and 
having a portion connectable to a wire, a cap initially seatable in an up 
position on said housing, and adapted to be forcibly pushed down from said 
up position to a down position on said housing, and means permitting 
insertion of said lead into the space enclosed by such housing and cap and 
for effecting connection in said space of said inserted lead with said 
electroconductive means. 
The terminal disclosed in such patent (the "Doyle patent") has been very 
satisfactory in the application therefor which it is disclosed in that 
patent, and which is as one of a plurality of insulated wire lead 
terminals (there being one such terminal per lead) mounted on a terminal 
board ordinarily connected up and otherwise serviced by experienced 
telephone company technicians. That disclosed terminal would, however, 
have the disadvantages, if provided for its connecting up, by technically 
unskilled persons, that the cap of the terminal detaches too readily from 
its housing, and that the connection in the connector of the wire lead 
inserted therein may be too easily opened up by pulling force exerted on 
the lead and causing the lead to slide out from the terminal strip by 
which it was previously gripped. 
SUMMARY OF THE INVENTION 
One or both of the disadvantages just mentioned are overcome according to 
the invention by providing one or both of the improvement features of (a) 
latching means operable when the cap is in the down position to 
unyieldably restrain it from being upwardly moved from said position in 
response to application to the terminal solely of lifting force exerted in 
the upward direction on the cap, and (b) strain relief means provided by 
said terminal and adapted, by frictionally contacting under force a 
portion of such lead distributed over a length thereof to isolate such 
connection from pulling force exerted on the lead. A connection according 
to the invention is not, however, necessarily limited just to a connector 
providing one or both of such improvement features but, rather, may be any 
connector defined by any of the claims hereof.

DETAILED DESCRIPTION OF EMBODIMENT 
Referring now to FIG. 1, the reference numeral 20 designates an electrical 
connector embodying the invention. Connector 20 comprises the components 
of a pair of electroconductive means 21a, 21b in the form of metallic, 
vertically extending terminal strips, a molded plastic insulative base or 
housing 22 for the strips 21, and a cap 23 for those strips. Connectors 
according to the invention may comprise a plurality of individual 
terminals each adapted to connect one wire to another wire. The connector 
is such a multiterminal connector which, as indicated by the dashed 
dividing line 24 on housing 22, is divided into duplicate left-and 
right-hand terminals 25a and 25b disposed side by side in the lateral 
dimension and containing, respectively, the terminal strips 21a and 21b. 
Shown in FIG. 1 in association with connector 20 are the free ends of a 
pair of insulated wire leads 30a, 30b comprising metallic cores 31a, 31b 
and insulated jackets 32a, 32b around these cores. Typically, the leads 30 
are tip and ring leads for a telephone set (not shown) disposed in, say, 
an apartment building at a location away from their shown free ends which 
may be, say, in the cellar of the building. 
Also shown in FIG. 1 is a stub cord 40 comprising a conventional modular 
telephone plug 41 adapted to be inserted into a mating modular jack to 
connect the mentioned telephone set to a telephone network, a plastic 
ribbon 42 fastened to and extending away from plug 40, and a pair of 
electrical wires 43a, 43b embedded in ribbon 42 and extending from 
connections with plug 41 through ribbon 42 to bare ends 45a, 45b of such 
wires extending out from the free end of ribbon 42. 
Considering now in more detail the components of connector 20, the terminal 
strip 21a is made of phosphor bronze or some other resiliently deformable 
electroconductive material, and the strip comprises a lower downwardly 
projecting stem 50a, a shank portion 51a above such stem and a support 
column 52a extending from such shank portion to an upper section 53a. 
Upper section 53a is a bifurcated section comprising a pair of tangs 54a, 
55a separated by a contact gap 56a in the lateral dimension and 
resiliently deflectable away from each other in that dimension. The tangs 
54a, 55a bear thereon respective cutting edges (not shown) adjacent to the 
gap 56a. 
Terminal 21b is a duplicate of terminal 21a. These terminals are similar to 
the terminal strip disclosed in the aforementioned Doyle patent, 
incorporated herein by reference and made a part hereof, which provides 
more details on the characteristics of the terminal strips 21 described 
herein. 
Coming to the base or housing 22, that component has therein a central 
chamber 60 (FIG. 7) peripherally enclosed by (FIG. 2) vertical front and 
back longitudinally-spaced walls 61, 62 and by vertical laterally spaced 
left- and right-hand side walls 63 and 64. At its lower end, compartment 
60 is closed (FIG. 9) by a bottom 65. Upstanding from bottom 65 are a pair 
of support pedestals 66a, 66b (FIG. 3). Pedestal 66a has formed therein a 
vertical slot 67a passing downward through the pedestal and through the 
compartment bottom 65. Pedestal 66 has a similar slot 67b therein. 
In the course of assembling connector 20, the shank portions of the 
terminal strips 21a, 21b are seated with a tight fit in, respectively, the 
slots 67a, 67b in the pedestals 66a, 66b so that the stems 50 of those 
terminals project downward beyond the underside of compartment bottom 65, 
and so that the upper sections 53a, 53b of the terminal strips are 
positioned upwards (FIG. 2) of the chamber 60 in the housing. With the 
terminal strips 21 so held positionally fixed in housing 20, the stems 50 
of these strips are peripherally enclosed by a skirt 59 extending on 
housing 22 downward beyond its chamber bottom 65. 
The chamber 60 is partly closed at its top by a shelf 70 (FIG. 1) extending 
laterally across the housing 22 at its front. Longitudinally behind the 
shelf the chamber has a top opening 69 bounded at its rear by a ledge 68 
(FIG. 7) projecting inwards from the top of back wall 62 of the housing. 
Extending into shelf 70 from its back side are two centrally located, 
rectangular, relatively wider and narrow notches (not numbered) of which 
the wider one extends into the shelf for a lesser distance than does the 
narrow notch. These two notches form in the top of the housing a guide 
passage 71 having laterally opposite margins of stepped configuration. The 
portions 72a, 72b of the shelf 70 which are on opposite sides of the 
laterally narrowest part of the guide passage 71 (and are also adjacent to 
the front housing wall) are shelf portions providing downward facing stop 
shoulders 73a, 73b. The significance of those shoulders will be later 
discussed. 
Disposed on shelf 70 are a pair of probes 75a, 75b located on portions 74a, 
74b of the shelf adjacent to its back side and on laterally opposite sides 
of the laterally widest part of the guide passage 71. Those probes are of 
square horizontal cross section and project upward from those shelf 
portions. The probes 75a, 75b at their top have slanting front and back 
faces 76 and 77 which meet at laterally extending edges 78 to form 
dihedral angles defined by those faces. The top triangular tips 79a, 79b 
of the probes 75 formed by the faces 76, 77 are convexities of which the 
outward surfaces have respective inflections 83a, 83b in the upward 
vertical direction relative to a horizontal surface passing through such 
tips. 
The housing 22 at its back has a molded plastic portion integral with the 
rest of the housing and providing a clip 80 therefor. The clip 80 has 
formed therein a deep horizontal notch 81 extending into the body of the 
clip from its left side (FIG. 3) and adapted to receive and retain therein 
(FIG. 7) the ribbon 42 of the stub cord 40. Moreover, the clip 80 also has 
formed therein a smaller vertical notch 82 for receiving therein a 
projecting rib (not shown) of a device which is adapted to receive and 
mount therein the connector 20. That device may be, say, a building 
entrance protector device in the cellar of the mentioned apartment 
building. 
In the course of assembling the electrical connector 20, the stub cord 40 
is fastened to the housing 22 by providing wire wound couplings 85a, 85b 
(FIGS. 9 and 8) of the bare wire ends 45a, 45b of the wires 43 of the stub 
cord to the downwardly projecting stems 50 of the terminal strips 21 
contained in the housing. After the stub cord has thus been fastened by 
the wire wound couplings 85 to the housing 22, the ribbon 42 of the stub 
cord is forced into the notch 81 in the clip portion 80 of the housing to 
be frictionally retained in that notch. 
Turning now to the cap component of the connector 20, the cap 23 at its top 
has a head 90 which is mostly solid plastic but has therein various 
passages soon described. At its front, the head has a pair of forwardly 
projecting noses 91a, 91b. Integrally joined to the underside of head 90 
is a downwardly extending web 92 having a bottom 93 and dividing on 
longitudinally opposite sides of such bottom into front and back 
downwardly extending legs 94 and 95 spaced longitudinally far enough apart 
that they are adapted to straddle the pedestals 66 in housing 22 when (as 
later more described) the cap is forced down into the housing 22 (FIG. 8). 
Below bottom 93, the legs 94 and 95 are longitudinally joined by a central 
crossbraces 86 (FIGS. 6 and 9) so that cap 23 is of "H" shape in its 
horizontal cross section below web bottom 23. The leg 95 of the cap 
carries on its back side (FIG. 6) a rearwardly projecting horizontally 
extending detent ridge 96 and a rearwardly projecting horizontally 
extending rounded detent rib spaced on the leg a short distance above 
ridge 96 leg. Ridge 96 provides on its top a slanting detent shoulder 98 
and, on its outer side, a wedging face 99. 
With regard to the various passages in cap 23, the web 92 has formed 
therein a pair of vertical channels 101a, 101b extending from the web 
bottom 93 upward through the web and then through the head 90 to terminate 
in openings therefor at the top of the head. Such passages 101 register 
with and are adapted to receive therein the terminal strips 21 projecting 
upward (FIG. 2) from the housing. 
Other passages in the cap are a pair of horizontal circular bores 102a, 
102b extending from the front of hoses 91a, 91b rearwardly through those 
noses and head 90 to intersect with, respectively, the channels 101a, 101b 
and to then extend rearwardly beyond them into a projecting overhang 103 
of the cap. Within that overhang, the bores 102a, 102b have blind ends for 
which, however, communication to the outside of the cap is provided by 
slit windows 104a, 104b. The bores 102a, 102b define paths 105a, 105b 
(FIGS. 1 and 2) for insertion of the leads 30a, 30b, into the cap and then 
to the channels 101a, 101b and post them into the overhang 103. 
Also formed as passages in the cap 23 are two apertures 110a, 110b having a 
square horizontal cross section slightly greater in size than the probes 
75 on housing 22 and adapted to receive those probes. The apertures 110a, 
110b extend in cap 23 upward from the bottoms of noses 91 to intersect 
with, respectively, the bores 102a, 102b and to then extend slightly 
upwards beyond them to terminate in top ends 111a, 111b of such apertures. 
As shown in FIG. 6 for the top end 111a, the portions 114a, 114b of 
connector 20 into which the top ends of those apertures penetrate are 
portions which have grooves 115a, 115b formed therein by such top ends. By 
virtue of those portions 114 having the configurations just described, the 
wall surfaces of such grooved portions have respective inflections 116a, 
116b in the upward vertical direction relative to the surfaces of such 
portions bounding bores 102 to either longitudinal side of the grooves 
115, and the portions 114 providing such inflections are portions having 
concavities therein. 
The cap 23 includes as an integral part thereof a resiliently deformable 
cantilever beam 120 having a lower fixed end 121 integrally coupled with 
the front cap leg 94 on the front side of that leg (FIG. 6). From that 
fixed end, the beam 120 extends upwardly and forwardly to a free end 122 
adapted to serve as a key button. In so extending upward, the beam passes 
through a slot provided laterally between the cap noses 91 to accommodate 
the beam. 
Beam 120 above its fixed end comprises a lower section 125 of full lateral 
width and an upper section 126 of reduced lateral width relative to 
section 125. That width reduction of the upper section produces on 
laterally opposite sides of the lower section 125 at its top a pair of 
upwardly facing stop shoulders 130a, 130b. As will later be apparent, the 
lower section 125 comprises part of a cap latching means while the upper 
section 126 constitutes a cap releasing means. To increase the resilient 
pliancy of the lower section, it has "cut-away" portions 127 which are 
disposed in that section around portions of a middle ridge 128 of the same 
longitudinal thickness as upper section 126, and which portions 127 are of 
reduced longitudinal thickness relative to elements 128 and 126. At its 
lower end, the lower section 125 has on its outside a slanting detent 
shoulder 129 and a wedging face 124 below that shoulder. 
USE OF THE EMBODIMENT 
To put the connector 20 into ready condition for use, the cap 23 is 
assembled with housing 22 (with the latter already including terminal 
strips 21, and being fastened to cord 40) so that the cap is seated in the 
up position on the housing. Such assembly of the cap and housing is 
effected as follows. With the cap being initially spaced above the housing 
as shown in FIG. 2, the downward end of the cap is lowered into the top 
opening 69 of the housing to cause the wedging faces 99 and 124 on the cap 
to first engage with, respectively, the ledge 68 and the shelf portions 72 
of the housing at the back and front, respectively, of that opening and to 
then move down past these engaged housing elements. Such downward movement 
is permitted by the wedging action which is created by the engagement with 
and movement of cap faces 99 and 124 relative to housing elements 68 and 
72, and which action resiliently bends the beam 120 backward enough to 
enable the downward end of the cap to longitudinally fit into the housing 
opening 69. Once the mentioned wedging faces on the cap have moved past 
the housing elements engaged thereby, the ledge 68 on the housing becomes 
positioned between the ridge and rib elements 96 and 97 on the cap, and 
the detent shoulder 129 on the cap beam 120 becomes positioned below the 
shelf portions 72b on the housing. The cap 23 is thus detained in its up 
positioned seated on the housing 22, the upper ends of the terminal strips 
21 being at that time received in the channels 101 in the cap. The cap, 
however, is only yieldably detained in that, because of the slant of the 
detaining shoulders 98 and 129, the cap by moderate lifting force thereon 
can be pulled up and away from the housing, and in that moderate downward 
force on the cap will cause the detent rib 97 to move down past ledge 68 
and thus free the cap for further downward movement. 
With the connector being so in ready condition, the wire leads 30 are 
guided along the shown paths 105 therefor to insert those leads into the 
bores 102 in the cap, and past the intersection of those bores with the 
channels 101 and then in such bores into the overhang portion 103 of the 
cap. The insertion of the leads is then stopped by the coming into contact 
of the free ends of such leads with the blind ends of the bores 102 in the 
overhang 103. 
As a next step, the cap 23 is forcibly pushed by hand into housing 22 to 
have the following effects. 
First, such driving down of the cap produces, relatively speaking, an 
upward movement in the cap channels 101 of the terminal strips 21 mounted 
by the housing. That upward movement initially positions the inserted 
wired leads 30 (now longitudinally transversing those channels) into the 
contact gaps 56 laterally disposed between the tongs 54 and 55 of such 
strips. Further upward relative movement of the strips causes a relative 
downward movement of the leads 30 in such gaps to bring the leads 30 into 
engagement with the cutting edges (not shown) on the tangs and to then 
move the leads further down into the gaps 56. Results are that the 
insulating jackets 32 of the leads are severed by such edges, and that, at 
the end of the cap's downward movement, the metallic cores 31 of the leads 
are in pressure contact with the tangs 54, 55 of the terminal strips 21 
(FIG. 9) to make an electrical connection with the terminal strips and to 
be electrically connected through such strips with the wires 43 of cord 40 
and with its modular plug 41. Further details are disclosed in the Doyle 
patent on the making of such electrical connection between either of leads 
30 and the electroconductive means constituting the corresponding terminal 
21. 
Second, the downward driving of the cap into the housing produces a 
relative movement of the probes 75 on the housing upward into the 
apertures 110 in the cap until such movement is stopped either by the legs 
94, 95 of the cap contacting the housing bottom 65 or by the head 90 of 
the cap contacting the housing's top. As shown by FIG. 8, the leads 30 
inserted into the bores 102 in the cap are slightly smaller in diametral 
size than the bores, and the grooved portions 114 of the cap bordering 
those bores and the convex tips 79 of the probes constitute upper and 
lower lead contacting means, respectively which are disposed in vertically 
registering relation on opposite sides of each of the paths 105 for the 
leads. Further, the respective surfaces of the grooved portions 114 and 
the convex probe tips 79 constitute matching inflections 116 and 83 in the 
same upward vertical direction from the horizontal lie of the bores 102. 
As further shown by FIG. 8, at the end of the relative upward movement of 
the probes 75 into the cap, the leads 30 are each contacted on opposite 
sides by the mentioned upper and lower lead contacting means, and the 
convex tips 79 of the probes press against, and force into the grooves 
115, the portions 140 adjacent thereto of the leads 30 so as to produce in 
these leads inflections 141 in the upward vertical direction relative to 
the lead's horizontal lie elsewhere in the bores. Such inflections in the 
leads match the surface inflections 116 and 83 provided by the grooved 
portions 114 and the convex probe tips 79. To put it another way, the 
closure towards each other of the grooved portions 114 and the convex 
prove tips 79 produce inflections in the previously straight paths for the 
leads, which inflections substantially correspond in size, shape and 
direction to the surface inflections of those portions and tips. 
The probe tips 79 and the connector portions 114 opposite them across bores 
102 together constitute shown relief means in that they are adapted, by 
their closure towards each other and a resultant mutual contacting of the 
portions of the leads contained between them, to partly or wholly insulate 
the connections of the leads 30 with terminal strips 21 from pulling 
forces exerted outside connector 20 on those leads. Such strain relief may 
be realized in connector 20 in one or both of two different ways. 
As a first way, when inflections are produced as described in leads 30 and 
in the paths 105, those inflections provide such strain relief even 
though, in the absence of pulling force on the leads neither the mentioned 
portions 114 nor the probe tips 79 contact under force the inflected lead 
portions 140. That is so because the effect of producing the inflections 
141 in the leads 30 will be to cause a pulling force on such a lead to 
produce a pressing of the lead against portions of one or both of the 
elements 79 and 114 to thereby generate a reactive friction force which 
opposes the pulling force. 
A second way to provide such strain relief is to design connector 20 so 
that an incremental amount of the downward displacement of the cap, 
produced at the end of its downward movement, is communicated by the 
inserted leads 30 to the probes 75 to resiliently depress the shelf 
portions 74 on which those probes are mounted, and so that, after all 
relative movement between the cap and housing has ceased, at least a 
fraction remains of that downward resilient deflection of the shelf 
portions. In that case, the resilient stress still existing in those shelf 
portions will urge the probes 75 upward to cause the elements 79 and 114 
to frictionally grip between them the lengthwise distributed adjacent 
portions 140 of the leads under the upward vertical force exerted by the 
probes so as to produce in the leads 30, when needed, a friction force 
directed to oppose the pulling force on the leads. The same effect can be 
produced by the resilient compression of the insulation leads 30 which can 
be caused by the hard gripping of the leads between the elements 79 and 
114 after termination of the down movement of the cap. Such second way of 
providing strain relief, can be used in conjunction with also providing 
such relief by the inflections 141 in the leads 30, but it can also be 
used even though, say, the surfaces of the elements 79 and 114 which 
contact the lead portions 140 are flat. An advantage of providing strain 
relief as described in one or both of such first and second ways is that 
it is produced automatically in response to downward pushing of the cap 
and is delayed until that time so as not to interfere with the insertion 
of the leads 30 into the bores 105. While if solely such second way is 
utilized to provide such strain relief, that downward pushing need not 
necessarily produce alterations in the configurations of paths 105 in the 
firm of inflections therein, such downward pushing will nontheless produce 
alterations in such path configurations in the form of constriction in 
such paths. 
As another effect of the push down of the cap, as the cap 23 is driven 
downward into the chamber 60 in housing 22, the lower section 125 of the 
cantilever beam 120 on the cap slides down past the shelf portions 72 of 
the housing in contact with such portion to be resiliently bent into a bow 
shape by such contact and sliding to thereby incrementally shorten the 
chordal length between the fixed end 121 of the beam and the upward facing 
stop shoulders 130 on the beam. Those stop shoulders are so positioned in 
the length of the beam that, when the downward pushing of the cap into the 
housing is arrested, those stop shoulders will be lower by a clearance 
than the adjacent downward facing stop shoulders 73 provided by the 
undersides of the shelf portions 72. Accordingly, the resiliently deformed 
lower section of the beam will spring back toward its original undeformed 
position so as, by a snap-fitting action, to position the lower 
upward-facing shoulders 130 on the beam 120 of the cap beneath the upper 
downward-facing shoulders 73 on the housing 22. The result is that, upon 
the application to the connector 20 of force which is solely lifting force 
exerted on the cap, the cap cannot be detached from the housing because, 
although such lifting force urges cap 23 as, a whole and its beam 
shoulders 130 upward, that upward urging is equally and oppositely opposed 
by a downward force 7hich is exerted by the housing shoulders 73 on the 
cap carried shoulders 130, and which downward restraining force 
progressively becomes greater as the upward urging force becomes greater. 
To put it another way, the greater such upward lifting force, the more 
firmly the upward and downward facing shoulders become engaged. That 
downward restraining force stands in contrast to the detaining force which 
holds the cap 23 in its up position when seated on housing 22 as shown in 
FIG. 7, but which detaining force becomes progressively less and 
ultimately yields as the upward lifting force on the cap progressively 
becomes greater. 
The described shoulders 73 and 130 and associated parts of the connector 20 
thus provide for each of the terminals 25a 25b in the connector a latch 
means operable when the cap 22 is in its down position on housing 22 to 
unyieldably restrain it (short of breakage of parts) form being detached 
from the housing in response to application to the connector or terminal 
of force which is solely lifting force exerted in the upward direction on 
the cap. That latch means provides the advantage that the cap cannot be 
casually detached from the housing so as to cause exposure of the 
electrical connections within the connector. Another advantage is that 
such latch means is automatically actuated in response to the downward 
pushing of the cap to provide its latching effect, so that it is not left 
to chance. While the engagement between the shoulders which produces that 
latching effect occurs only at the front part of the connector, the 
shoulders cannot be disengaged by angular tilting of the cap relative to 
the housing inasmuch as the part of the cap which is received into housing 
22 fits too tightly therein to permit an amount of tilting which would 
nullify the latching effect. 
While the cap may be latched permanently as described to the housing, there 
may, however, be instances when it would be desirable to remove cap 23 
from housing 22. Such removal may be accomplished by the use of the cap 
releasing means provided by the upper section 126 of the beam 120 in the 
cap. To effect such removal, rightward horizontal force (FIG. 8) is 
exerted by hand on the key button provided by the free end 122 of section 
126 of beam 120 to resiliently bend the beam to bring it to a position at 
which the shoulders 130 thereon become disengaged from the shoulders 73 on 
the housing. Then as long as the beam is held by hand in that position, 
the cap 23 may readily be lifted up to separate it from the housing 22. 
The described latching of the cap 23 to the housing 22 by positioning the 
cap shoulders 130 beneath the housing shoulders 73 is entirely 
satisfactory even though some clearance exists beneath the upper and lower 
ones of those shoulders after the cap has been driven to its down position 
and then released. If desired, however, any play in the vertical direction 
of the relative positioning of the cap and housing can be ended by 
providing for resilient deflection downward of the housing shelf portions 
74 as earlier described, and, after the cap has been pushed as far as 
possible down into the housing, by utilizing that deflection of those 
shelf portions 74 to act through probes 75 and leads 30 to produce in the 
positioning of the cap an incremental upward rebound which eliminates all 
clearance between the shoulders 130 and 73 and brings them into pressure 
contact maintained by the remaining resilient stress in the deflected 
shelf portions 74 and/or by residual resilient compression in the 
insulation of the leads 30. 
The above described embodiment being exemplary only, it is to be understood 
that additions thereto, omissions therefrom and modifications thereof can 
be made without departing from the spirit of the invention. For example 
without restriction, while the engagement and disengagement of the upward 
facing and downward facing shoulders on, respectively the cap and housing 
(so as to latch and unlatch the cap) have been described earlier herein as 
produced by movements of the beam 120 carried by cap 23, the same actions 
may be produced by the agency of an equivalent device carried by housing 
22. Accordingly, the invention is not be be considered as limited save as 
is consonant with the scope of the following claims.