U.S. patent application number 12/928843 was filed with the patent office on 2011-04-21 for manufacture of waterproof wire connectors.
This patent application is currently assigned to THE PATENT STORE LLC. Invention is credited to James C. Keeven, Lloyd Herbert King, JR..
Application Number | 20110088254 12/928843 |
Document ID | / |
Family ID | 43769741 |
Filed Date | 2011-04-21 |
United States Patent
Application |
20110088254 |
Kind Code |
A1 |
King, JR.; Lloyd Herbert ;
et al. |
April 21, 2011 |
Manufacture of waterproof wire connectors
Abstract
A method of manufacturing gel containing wire connectors with a
silicone gel that remains in an unseparated state wherein the
temperature of the gel precursors are elevated before being mixed
and dispensed into the cavity of a wire connector where the mixed
gel precursors are allowed to cool and cure without the necessity
of additional heating of either the mixed gel precursors or the
wire connector.
Inventors: |
King, JR.; Lloyd Herbert;
(Chesterfield, MO) ; Keeven; James C.; (O'Fallon,
MO) |
Assignee: |
THE PATENT STORE LLC
|
Family ID: |
43769741 |
Appl. No.: |
12/928843 |
Filed: |
December 21, 2010 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
12148810 |
Apr 23, 2008 |
|
|
|
12928843 |
|
|
|
|
Current U.S.
Class: |
29/747 |
Current CPC
Class: |
H05K 3/103 20130101;
Y10T 29/4913 20150115; Y10T 29/49171 20150115; H01R 4/22 20130101;
H01R 13/5216 20130101; Y10T 29/4922 20150115; B05D 1/34 20130101;
Y10T 29/49176 20150115; Y10T 29/49146 20150115; Y10T 29/53209
20150115 |
Class at
Publication: |
29/747 |
International
Class: |
H01R 43/20 20060101
H01R043/20 |
Claims
1.-15. (canceled)
16. An apparatus for manufacturing a gel containing wire connector
comprising: a container for holding a first gel precursor; a mixing
valve; a first heat transfer member for transferring the first gel
precursor to the dispensing valve while elevating the temperature
of the first gel precursor to a temperature approaching the
temperature of the heat transfer member; a second heat transfer
member for transferring the second gel precursor to the dispensing
valve while elevating the temperature of the second gel precursor
to a temperature approaching the temperature of the second heat
transfer member; and a nozzle for receiving and mixing the first
gel precursor and the second gel precursor and injecting a mixture
of the first gel precursor and the second gel precursor into a wire
connector.
17. The apparatus of claim 16 including a conveyor for carrying the
wire connector to a position to receive the mixture of the first
gel precursor and the second gel precursor and to carry the wire
connector with the mixture of the first gel precursor and the
second gel precursor to a storage bin for completion of the curing
as the product is being prepared for shipment.
18. The apparatus of claim 16 wherein the first heat transfer
member is a heated hose having a length sufficient so that the
delivery of the first gel precursor through the heated hose is
sufficient to bring the temperature of the first gel precursor to a
temperature approaching the temperature of the heated hose as the
first gel precursor discharges into the dispensing valve and the
second heat transfer member is a heated hose having a length
sufficient so that the delivery of the second gel precursor through
the heated hose is sufficient to bring the temperature of the
second gel precursor to a temperature approaching the temperature
of the second heated hose as the second gel precursor discharges
into the dispensing valve.
19. The apparatus of claim 16 including a plurality of twist on
wire connectors held in an upright condition on a conveyor.
20. The apparatus of claim 18 including a pressure source for
maintaining the first gel precursor and the second gel precursor at
a pressure sufficient to force the first gel precursor and the
second gel precursor into the dispensing valve.
21. The apparatus of claim 16 including a heater for maintaining
the temperature of the first heat transfer member and the second
heat transfer member at a temperature within the range of about 45
degrees C. to 65 degrees C.
Description
FIELD OF THE INVENTION
[0001] This invention relates generally to manufacturing waterproof
wire connectors and, more specifically, to a process and apparatus
for manufacturing wire connectors with cured gels.
CROSS REFERENCE TO RELATED APPLICATIONS
[0002] None
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0003] None
REFERENCE TO A MICROFICHE APPENDIX
[0004] None
BACKGROUND OF THE INVENTION
[0005] The concept of using a viscous sealant such as a silicone in
a wire connector to waterproof the wire connector is known in the
art. Examples of use of viscous sealants in twist-on wire
connectors is shown in King U.S. Pat. No. 5,113,037. Other types of
silicones such as silicone gels, which cure to a soft gel like
consistency are used for protecting extremely delicate electronic
components from shock and vibration as well as waterproofing the
encapsulated components. Generally, the silicone gels have a tacky
surface and form a mechanical bond to most surfaces making them
ideal for vibration protection. The viscous sealants, which remain
in a viscous state, require no curing phase and can be injected
directly into a wire connector while the conventional method of
creating gels, which are made from mixing two components, require a
curing phase that requires additional handling and processing.
[0006] The known process for formation of the silicone gels
includes the mixing of a first silicone gel precursor with a second
silicone gel precursor and then curing the gel mixture at an
elevated temperature for a period of time. Typically, the gel
mixtures are cured by heating the gel mixture and maintaining the
gel mixture at temperatures ranging from 25.degree. C. to
150.degree. C. at times ranging from 5 minutes to 24 hours.
Generally, the shorter cure times are used with gel mixtures that
are cured at higher temperatures and the longer cure times are used
with gel mixtures that are cured at lower temperatures which can
require a separate or isolated curing of the product and the gel.
Also when a silicone gel mixture is used in small amounts, for
example in wire connectors such as twist-on wire connectors,
oftentimes the silicone gel mixture may not cure properly. Another
difficulty in manufacturing wire connectors with gels is that
curing the gel mixture by heating the wire connector and the gel
mixture renders the manufacturing process more difficult and more
costly. Another manufacturing difficulty is that it has been found
that when small amounts of a gel mixture are cured by the prior art
proscribed curing process separation of the cured gel mixture can
occur which leaves an oily film on the cured gel mixture oftentimes
making it unacceptable for use in wire connectors.
SUMMARY OF THE INVENTION
[0007] A method and apparatus for manufacturing gel filled wire
connectors where the wire connector remains at room temperature and
the gel mixture in the wire connector cures to an unseparated state
through a process of elevating the temperature of the gel
precursors before dispensing the mixed gel precursors into the
cavity of a wire connector, which can remain at room temperature,
as the mixed gel precursors are allowed to cool and self cure in
the wire connector.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a schematic of a system for dispensing gel
precursors into the cavity of a wire connector;
[0009] FIG. 2 is a partial sectional view of a twist on wire
connector; and
[0010] FIG. 3 is a sectional view of the needle nozzle.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] FIG. 1 is a partial schematic of a system 10 for dispensing
a mixed heated silicone gel precursor into the cavity of a wire
connector to form a wire connector with a gel therein without
having to separately cure the gel in the wire connector. System 10
includes a base member 11 that supports a container 12 containing a
first silicone gel precursor 17 and a container 13 that contains a
second silicone gel precursor 18. A source of compressed air 14
connects to base 11 to allow the container 12 to be pressurized and
thereby cause the gel precursor 17 in container 12 to flow through
hose 20. Similarly, the source of compressed air 14 allows
container 13 to be pressurized to cause the gel precursor 18 in
container 13 to flow through hose 21. Silicone gels that are formed
from two or more separate gel precursors are commercially available
from various United States suppliers. System 10 includes a first
heat transfer member 20 for simultaneously heating and transferring
the gel precursor in container 12 to an unheated dispensing valve
23. Heat transfer member 20 provides on the go heating of the first
gel precursor 17 and may for example comprise a heated hose 20 that
extends between container 12 and dispensing valve 23. Similarly,
heat transfer member 21 provides for simultaneously heating and
transferring the gel precursor in container 13 to a dispensing
valve 23. Heat transfer member 21 provides for on the go heating of
the second gel precursor 18 and may for example also comprise a
heated hose 21 that extends between container 13 and dispensing
valve 23. In the example shown heat transfer member 20 provides on
the go heating of gel precursor 17 as the gel precursor travels
from container 12 to dispensing valve 23 and similarly, heat
transfer member 21 provides for on the go heating of gel precursor
18 as the gel travels from container 13 to dispensing valve 23
although other methods and means of heating the gel precursors may
be used which do not use on the go heating. An example of heat
transfer members suitable for use herein are heated hoses which are
commercially available from suppliers of hoses and can include a
resistance heater located along the length of the hose.
[0012] The dispensing valve 23, which receives the heated gel
precursors 17 and 18 is shown in section in FIG. 3 and includes a
first chamber 36 containing gel precursor 17 and a second chamber
35 containing gel precursor 18. A remote controlled shut off valve
38 at the bottom of chamber 36 allows one to open and close port 39
to thereby control the delivery of precursor 17 to the needle
nozzle 24. Similarly, a remote controlled shut off valve 37 at the
bottom of chamber 35 allows one to open and close port 40 to
thereby control the delivery of precursor 18 to needle nozzle 24.
Shut off valves 37 and 38 are remotely controlled by means such as
by solenoids or the like (not shown).
[0013] FIG. 3 illustrates that the precursor 18 exits port 40 as a
cylindrical strand 18a and that precursor 17 similarly exits port
39 as a cylindrical strand 17a. As the stands proceeds down the
needle nozzle 14 mixing occurs. When the precursor 17 and precursor
18 reach the terminus end of the needle nozzle (designated by
M.sub.x) the precursor 17 and precursor 18 are mixed to form the
mixed gel precursor 27 that is injected into a wire connecter.
[0014] As can be seen in FIG. 1-FIG. 3, the heated gel precursor 17
in hose 20 and the heated gel precursor 18 in hose 21 are mixed in
needle nozzle 24 immediately prior to dispensing from needle nozzle
24 to form a heated mixed gel precursor 27. The heated mixed gel
precursor 27 is then dispensed directly into a cavity or chamber in
a wire connector 26 as illustrated in FIG. 1. As can be seen from
the above the gel precursors while heated above room temperature
are kept in a heated and separate state until immediately prior to
injection into the cavity of the wire connector.
[0015] In operation of the manufacturing system 10 a plurality of
wire connecters, such as twist on wire connectors 26, are held in
an upright position on a moving support such as a conveyor 25 that
moves wire connector 26 beneath the nozzle 24 so that the wire
connector 26 is in a position to receive a charge of the heated
mixed gel precursor 27 from nozzle 24. Typically, the dispensing
valve 23 is set for intermittent dispensing of the mixed gel
precursor 27 by a controller (not shown) which opens and closes
valves 37 and 38. That is, the nozzle 24 dispenses a charge of
heated mixed gel precursor when wire connector 26 is located in a
charge position beneath the needle nozzle 24 and suspends or
interrupts dispensing to simultaneously allow the gel filled wire
connector to move away from the charge position beneath nozzle 24
while an empty wire connector is moved to a charge or gel receiving
position below needle nozzle 24. In the embodiment shown the wire
connectors 26 are twist on wire connectors having an open top and a
spiral coil in the connector for engaging and securing wires
therein. Although twist on wire connectors are shown other types of
wire connectors may be filled by the apparatus and method of the
present invention. In the system 10 the mixed heated gel precursor
27 is dispensed directly into the cavity of the twist on wire
connectors 26 and cures in the wire connector which can remain at
room temperature (typically about 20.degree. C.), thus eliminating
the need to heat the wire connectors or allow excessive time for an
ambient cure that disrupts a normal manufacturing process. The
process as described has been found to eliminate gel separation
that can occur when a gel mixture is cured by the gel manufactures
proscribed process. While needle nozzles are described herein other
types of dispensers of nozzles that can mix the gel precursors may
also be used.
[0016] FIG. 2 is a partial sectional view of a twist on wire
connector 26 revealing a cavity or chamber 26a in the twist on wire
connector 26 with the heated mixed gel precursor 27 therein.
Although a twist on wire connector 26 is illustrated other types of
wire connectors may be filled with a heated premixed silicone gel.
In addition the method may be used for injecting damping materials
into wire connectors or other devices.
[0017] Thus, the method includes injecting a heated mixed silicone
gel precursor 27 into a cavity 26a of wire connector 26 to form a
silicone gel in a wire connector where the gel therein remains in
an unseparated state therein. To heat the gel precursors one may
direct a first gel precursor at room temperature through a heat
transfer member maintained at a temperature in the range of about
45 C to 65 C at a flow rate that allows the first gel precursor to
approach the temperature of the heat transfer member as the first
gel precursor exits the heat transfer member and may also direct a
second gel precursor at room temperature through a separate heat
transfer member also maintained at a temperature in the range of
about 45 C to 65 C at a flow rate that allows the second gel
precursor to approach the temperature of the second heat transfer
member as the second gel precursor exits the separate heat transfer
member. One then mixes the first gel precursor, which is at a
temperature approaching the temperature of the first heat transfer
member, with the second gel precursor, which is at a temperature
approaching the temperature of the second heat transfer member to
form a heated mixed gel precursor in a chamber 23a of the
dispensing valve 23 where the temperature of both gels before
mixture are the same or about the same. Next, one dispenses the
heated mixed gel precursor 27 into a cavity of a wire connector 26
and cures the mixed gel precursor without heating the wire
connector, which is at room temperature, to produce a gel
containing wire connector 26 wherein the gel in the wire connector
remains in an unseparated state during the shelf life of the gel.
It has been found that the method provides a cured gel that remain
in an unseparated state i.e. no oily film if each of the gel
precursors are heated sufficiently so that when the heated gel
precursors are mixed they form a single heated mixed gel precursor
that can be placed in a wire connector that need not be heated
thereby eliminating a step of having to heat the wire connector to
cure the gel. Although there is no bright line a temperature range
of about 45.degree. C. to 65.degree. C. has been found an effective
range for heating the gel precursors to enable formation of gel in
a wire connector that remains in an unseparated state. Similarly,
while no bright line a minimum temperature of about 25.degree. C.
above room temperature has been found effective for heating the gel
precursors to enable formation of gel in a wire connector that
remains in an unseparated state.
[0018] A feature of the manufacturing process using system 10 is
that it allows one to store two separate gel precursors at room
temperature (typically about 20 degrees C.) and then in an
on-the-go process temporarily heat the two separate gel precursors
as they flow to a dispensing valve 23 which eliminates the need to
heat the entire gel precursors. In the present manufacturing
process neither the dispensing valve 23 or the wire connectors 26
require heating to cure the gel in the wire connector thus
eliminating the need for additional heating and at the same time
avoiding gel separation that can occur with conventional curing
that may render the wire connector unsuitable for use.
[0019] With the method of the invention one can inject mixed
silicone gel precursors into a cavity of an empty wire connector 26
to form a silicone gel 27 wherein the gel therein remains in an
unseparated state. Typically, the gel separation with conventional
curing of silicone gel has been found to be more pronounced when
the charge of dispensed gel is small. While there is no abrupt
transition as to the size of the charge where gel separation occurs
generally a more noticeable separation occurs when the charge is
about 10 grams or less.
[0020] The method includes directing the first gel precursor at the
room temperature through a heat transfer member 20 which is
maintained at a temperature in the range of about 45 C to 65 C at a
rate that allows the first gel precursor to approach the
temperature of the heat transfer member. Similarly, directing the
second gel precursor at room temperature through a separate heat
transfer member 21 maintained at a temperature in the range of
about 45 C to 65 C at a rate that allows the second gel precursor
to approach the temperature of the second heat transfer member.
While the gel precursor are heated on the go as the gel precursor
are transferred to a dispensing valve it is envisioned that other
methods of heating the gel precursors prior to mixing the gel
precursors may be used.
[0021] Thus the process of manufacturing a gel filled wire
connector includes the steps of heating the gel precursors to the
proper temperature and mixing the first gel precursor at a
temperature approaching the temperature of the first heat transfer
member 20 with the second gel precursor at the temperature
approaching the temperature of the second heat transfer member 21
to form a heated mixed gel precursor 27 in a dispensing valve 23.
One can then dispense the heated mixed gel precursor 27 into a
cavity 26a of a wire connector 26 and then carry the wire connector
with the mixed gel precursor to a storage bin for completion of the
curing during the preparation of the product for shipping.
[0022] Once dispensed therein one can allow the heated mixed gel
precursor to self cure at room temperature without additional heat
to thereby produce a gel containing wire connector wherein the gel
27 in the wire connector remains in an unseparated state during the
shelf life of the gel. While the gel precursors are mixed in an
unheated needle nozzle 24 in some instances one may want to heat
the needle nozzle.
[0023] While the cause of the gel separation is not fully
understood the invention herein provides a method and apparatus for
eliminating the undesirable separation of cured silicone gels in
wire connectors.
* * * * *