U.S. patent number 3,894,731 [Application Number 05/369,836] was granted by the patent office on 1975-07-15 for marker assembly.
This patent grant is currently assigned to Raychem Corporation. Invention is credited to Joseph H. Evans.
United States Patent |
3,894,731 |
Evans |
July 15, 1975 |
Marker assembly
Abstract
Described herein are marker assemblies comprising an elongate
denticule whose flat, pendent tines bear in snug and slidable
relation heat recovered sleeves which conform to the flattened
configuration of the tines. After positioning generally tubular
heat recoverable sleeves over the pendent tines and recovery of the
same, printed information may be imparted to the tine-borne
sleeves, which thereafter may be removed from the denticular
support and employed as identifying markers for electrical wire and
the like.
Inventors: |
Evans; Joseph H. (Palo Alto,
CA) |
Assignee: |
Raychem Corporation (Menlo
Park, CA)
|
Family
ID: |
23457124 |
Appl.
No.: |
05/369,836 |
Filed: |
June 14, 1973 |
Current U.S.
Class: |
269/47; 40/316;
101/4; 101/35; 264/230; 264/132; 400/662 |
Current CPC
Class: |
H01B
7/368 (20130101); G09F 3/0295 (20130101); G09F
3/06 (20130101) |
Current International
Class: |
G09F
3/06 (20060101); H01B 7/36 (20060101); G09F
3/04 (20060101); B23q 003/00 () |
Field of
Search: |
;40/316
;101/4,5,8,11,35,43,44,47R ;264/130,132,230 ;269/47 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lake; Roy
Assistant Examiner: Bicks; Mark S.
Attorney, Agent or Firm: Lyon & Lyon
Claims
I claim:
1. An assembly comprising:
a. a flexible support spine comprised of an elongate spine from at
least one side of which transversely projects a train of
substantially parallel tines spaced one apart from the other, said
support admitting of flexure so as to diminish the distance between
opposite ends thereof while retaining said tines in mutually
parallel orientation; and
b. a plurality of tubular sleeves;
each of said sleeves being snugly and slidably disposed over one of
said tines so as to admit of removal therefrom when drawn past the
ends of said tines distant from said spine.
2. An assembly according to claim 1 wherein said tines are
substantially flat.
3. An assembly according to claim 2 wherein said sleeves are
flattened.
4. An assembly according to claim 3 in which said sleeves retain
their flattened configuration when removed from said tines.
5. An assembly according to claim 4 in which a release agent is
disposed between said tines and said sleeves.
6. An assembly according to claim 5 in which said tines are
integral with said spine.
7. An assembly according to claim 5 in which a train of
perforations are provided along the length of said spine.
8. An assembly according to claim 4 in which said sleeves are
comprised of a crystalline, cross-linked polyolefin.
9. An assembly according to claim 4 in which said sleeves are
comprised of a cross-linked polymer.
10. An assembly according to claim 3 in which flattened surfaces of
said sleeves bear printed information.
11. An assembly according to claim 3 in which, upon removal from
said tines, said sleeves are heat recoverable to a lesser
transverse dimension.
12. An assembly according to claim 1 in which, upon removal from
said tines, said sleeves are heat recoverable to a lesser
transverse dimension.
13. An assembly according to claim 12 in which said sleeves are
comprised of a cross-linked polymer.
14. An assembly according to claim 13, wherein said polymer is a
polyolefin.
Description
BACKGROUND OF THE INVENTION
Industry finds frequent need for identifying markers employed in
tagging components of complicated assemblies. This is particularly
so in the case of complex electrical assemblies such as, eg, wiring
systems employed in aircraft and the like. In such cases, the
practice heretofore has been to impress identifying characters into
the insulation of electrical conductors, an expedient which risks
impairment of insulative integrity. More recently, it has become
more common to impress or print identifying information onto
plastic tubes which are then slipped over the opposite ends of
electrical conductors, permitting their tracing when combined with
other such conductors in a cable bundle. That process, proceeding
as it does on a substantially piecemeal basis, has proved
undesirably laborious and, in addition, the dimensional tolerance
required for facile addition of the tubular markers to electrical
conductors has permitted their free movement on the conductor, so
as to require a sharp bend in the wire end to prevent loss of the
marker during handling of the free conductor.
Conceivably, the problems of piecemeal printing on wire markers and
the like could be alleviated to a degree by a "ticker tape"
approach in which a tube was flattened and fed through a
typewriter. However, such a system would require extensive
typewriter feed system modifications. Moreover, the type, ribbon
and platen of a conventional typewriter are designed to make clean
impressions on relatively hard, smooth surfaces. In the case of a
merely flattened tube, the keys would strike a double layer of soft
plastic separated by a small air gap, likely resulting in fuzzy,
multiple impressions with standard type mechanisms. Again, by the
ticker tape route, the markers are attached in order end to end, so
that only the markers at the ends of any given group would be
available for installation. Moreover, care would be required to
prevent a twist in the tube during the typing since any twist would
causes the type to spiral about the tube. With the "ticker tape"
tube designed to be heat-shrinkable for minimum bulk installation
on a wire or cable, it would not be susceptible to radiant heating
to render indelible printed characters thereon, because that
heating would prematurely effect heat recovery. Finally, such a
tubular marker, unless made heat recoverable would continue to pose
the retention problem previously alluded to, ie, the necessity that
wire ends be bent to prevent loss during handling after marker
application.
Until the present invention, a need existed for a marker system
free of the foregoing problems.
BRIEF SUMMARY OF THE INVENTION
According to this invention there is provided an assembly and a
method for forming such an assembly, the assembly comprising a
support having an elongate spine from at least one side of which
transversely project a plurality of flat tines spaced one apart
from another, and a plurality of flattened tubular plastic sleeves
snugly and slidably disposed over the tines so as to permit removal
therefrom when drawn past the ends of the tines distant from the
spine. The sleeves are heat recovered onto the tines, assuming
their flattened configuration so as to present a flat surface to a
printing mechanism such as a typewriter key, which key is enabled
to leave on the sleeve surface a clear impression by reason of the
backstop provided during typing by the tine. The heat recovered
sleeves retain their flattened configuration when removed from the
tines of their denticular support. However, when pressure is
applied from their opposite sides, they open out to receive a wire.
Release of pressure causes the information-bearing sleeve attempt
to reassume its flattened configuration, so that the marker sleeve
grips the wire about which it has been disposed much in the manner
of a spring clip.
The manner in which these and other objects and advantages of the
invention are achieved will become clear from the description of
preferred embodiments which follows and from the accompanying
drawing in which:
FIG. 1 is a partial pictorial view of an assembly according to one
embodiment of this invention prior to heat recovery of the sleeves
about appendages of a denticular support;
FIG. 2 is a partial pictorial view of the assembly of FIG. 1
following heat recovery of the sleeves;
FIG. 3 is a partial pictorial view of a typewriter platen bearing
an assembly like that of FIG. 2 in the course of the addition of
printed information thereto; and
FIGS. 4 and 5 are end views of an electrical conductor and
respectively illustrate the retentive "spring-action" of marker
sleeves formed according to this invention.
DETAILED DESCRIPTION OF THE INVENTION
With reference first to FIGS. 1 and 2, from one side of elongate
spine 10 project a plurality of flat tines 11 spaced one apart from
another. Alternatively, of course, tines could extend from each
side of the spine, facilitating typing of identical information on
the so aligned sleeve pairs borne by the oppositely extending
tines. Heat recoverable sleeves 12 are disposed over individual
ones of tines 11. Preferably, a release agent is disposed between
the sleeves and tines, as by dip-coating the tines in such an agent
or by nip-coating with such an agent the interior of a tubular
member from which sleeves 12 are later cut. As appears from FIG. 2,
upon heat recovery of the sleeves, the recovered sleeves 12' snugly
and slidably conform to the flattened configuration of the tines
11, while admitting or ready removal therefrom when drawn past the
ends of the tines distant from spine 10.
One advantage of this invention is that the denticule-sleeve
assembly admits of facile impartation of printed information to the
sleeves. FIG. 3 depicts the platen of a conventional typewriter
modified essentially only in that indentations have been cut into
the hard rubber surface of the platen to receive and position the
sleeves for presentation to the typewriter keys (additionally, if
desired as an aid in registration, the platen may be provided with
a sprocket wheel whose teeth 13 engage a train of perforations 14
disposed along the length of spine 10). Thus, with but minor
modification, a conventional typewriter platen can be ideally
configured for rapid printing of identifying information on the
marker sleeve assembly. The unindented portion of the platen can be
used for conventional typing or an unmodified platen substituted by
the typist whenever conventional typing is called for.
Typically, the heat absorptive characteristics of the dark printed
characters will be such as to permit their being rendered indelible
by exposure to radiant heat, all without unduly discoloring in the
surrounding, printed portions of the flattened surface. Thus, once
printed indicia are added to the marker assembly, the same can be
conveyed past, for example, an infrared source, effectively and
indelibly "burning" the characters into the substance of the
sleeve.
Preferably, the uncovered sleeves 12 are manufactured so as to
"remember" an interior circumferential dimension on the order of
twice the width of tines 11 so that while recovery results in a
snug disposition of the sleeves over the tines, the sleeves do not
tend to substantially further recover when freed of the tines and
raised to their recovery temperature. However, in particular
instances where it is desired that the marker sleeve once free of
its tine support and disposed over a wire or the like be heat
recoverable to a low profile configuration, that may be done simply
by appropriate sleeve dimensioning prior to impartation of heat
recoverability. In such cases, the tendency of sleeves recovered
about the tines to attempt further recovery when subjected to
radiant heat in course of rendering indelible their printed indicia
is thwarted by the tines themselves.
Generally, the unrecovered sleeves are recoverable to an interior
circumferential dimension ranging from about the width of the tines
11 to twice their width, depending upon whether one wishes further
recovery once the sleeve is disposed about a wire.
FIGS. 4 and 5 illustrate the retentive spring-action of a marker
sleeve 15 prepared according to the invention when disposed about
an electrical conductor 16. With reference to FIG. 14, imposition
of pressure on opposite edges 17 and 18 of the sleeve causes its
mid-portions to bow out, permitting ready insertion of conductor
16. When pressure is released, the flexible sleeve clamps the
conductor 16 so that while on the one hand it is retained during
handling of conductor 16, on the other it may be readily rotated
about the conductor to present the identifying information it bears
to whatever direction.
The denticular support material is chosen to withstand exposure to
the temperature of sleeve recovery and in the case where it is
desired that sleeves be further heat recoverable when removed from
their tine supports, is made sufficiently rigid as to withstand
recovery forces without substantial deflection. At the same time,
it is preferred that the material be sufficiently flexible as to
admit of disposition about the platen of a conventional typewriter.
In the case where the sleeves borne by the support are to be
exposed to relatively greater temperatures in order to render
printed characters thereon indelible, the support preferably has a
high heat deflection temperature. However, as discussed infra, most
of that portion of the support not covered by the sleeves recovered
thereon is heatshielded during the indelibilization process, so
that the support does not "see" temperatures of the magnitude
"seen" by the exposed sleeve surface. The preferred denticular
support material is nylon 66, although those skilled in the art
will readily appreciate that many other materials may be used, eg,
stiff cardboard, flexible metal stock, etc. The tines are
preferably integral with the spine element of the support, and in
such case the denticule is cut from sheet stock in such manner as
to insure that any burrs are directed away from that surface
adjacent the recovered sleeve surface upon which printing is to be
effected. Otherwise, it may be that in course of typing portions of
the sleeve will be "impaled" on the burrs, making removable of the
sleeve from its supporting tine somewhat difficult.
As before noted, the release agent may be coated on the denticular
support or alternatively coated on the interior of the sleeves.
Where a lubricious release material is used, preferably it is one
which either is not volatilized during indelibilization or one
whose volatile by products are not harmful. Preferred as a release
agent or lubricant is a mixture of 95 parts by weight
tricholoroethane and 5 parts by weight silicone stopcock grease
such as that available from the Dow Corning Corporation.
The heat recoverable sleeves of the invention are formed from
material comprising polymeric material capable of having plastic or
elastic memory imparted thereto. Materials having such memory have
been dimensionally changed from an original heat stable
configuration to a dimensionally heat unstable configuration
tending to move in the direction of the original configuration upon
the application of heat alone. The terms "plastic memory" and
"elastic memory" are used interchangeably herein and are intended
to be mutually inclusive.
Examples of such heat recoverable materials are found in Currie,
U.S. Pat. No. 2,027,962, Cook et al., U.S. Pat. No. 3,086,242, and
Clabburn, U.S. Pat. No. 3,721,749, the disclosures of which are
incorporated herein by reference. One method of making a heat
recoverable material consists in exposing a thermoplastic material
to an amount of heat which is insufficient to allow the material to
melt but sufficient to allow the molecular structure to become
distorted; and then distorting the material to a new configuration
and cooling the material in its distorted state. Subsequent
increases in tempurature sufficient to reduce locked-in stresses
caused by the initial plastic deformation will cause the article to
tend to recover to its initial state.
Another manner in which heat recoverable articles are generally
made involves the formation of a polymeric article having a first
dimension, followed by crosslinking of the polymer. The
crosslinking can be effected by chemical means, eg, with peroxides,
or by irradiation or by combinations of the two. Radiation employed
can be of various types including charged particles, ie, beta and
alpha, neutral particles, ie, neutrons, and electromagnetic, ie,
gamma and ultraviolet, as is well known. Subsequent heating of the
material will melt the crystals in a crystalline thermoplastic
material or significantly lessen other internal molecular forces
such as hydrogen bonding or dipoledipole interactions to an extent
sufficient to allow distortion of the product. Upon cooling of the
heated and distorted article, there is obtained a product which
remains in its distorted shape while at room temperature, due to
the reformation of strong interchain forces such as crystallinity
which at low temperatures dominate the contrary stresses resulting
from crosslinking. Upon reheating, the crosslink forces become
dominant and the material tends to recover to its original
geometry.
When irradiation is used, doses of any desired amount can be used
although, generally, a dosage of from 5 to 50, preferably 20-25
megarads will be sufficient.
An exemplary of the polymeric materials to which heat
recoverability can be imparted by the above and other means may be
mentioned polyolefins such as polyethylene, polybutene, various
copolymers of ethylene, propylene and butene, polyvinyl halides,
eg, polyvinyl chloride; ionomers and polyurethanes.
For optimal printability, the polymeric material of which the
recoverable sleeve is formed contained a substantial proportion of
filler material. The preferred sleeve material contains 40 parts by
weight low density polyethylene, 15 parts by weight
ethylene-ethylene acrylate copolymer, 8 parts by weight white
pigment, 31 parts by weight flame retardant, and 6 parts by weight
antioxidant. The recovery temperature of a sleeve so composed is on
the order of about 105.degree.-110.degree.C.
Typewritten information contained on sleeves formed of the
foregoing preferred composition was indelibilized by exposing the
support-borne sleeves to a quartz tungsten filament for a short
period (eg, approximately 0.7 seconds) during which time the
temperature of the print portions of the sleeves is believed to
have been raised to ca. 315.degree.C. Where this preferred
additional step of the printing process is practiced, those skilled
in the art of plastics printing are well able to determine what
times and temperatures will suffice for whatever plastic
material.
While my invention has been described by reference to preferred
embodiments thereof, it will be understood that the invention is
not limited thereto, but only to the lawful scope of the appended
claims.
* * * * *