U.S. patent application number 10/449744 was filed with the patent office on 2006-02-23 for arrangement for connecting a rod end to a headed pin and method of manufacture.
Invention is credited to Gregory P. Ruhlander.
Application Number | 20060039748 10/449744 |
Document ID | / |
Family ID | 30118598 |
Filed Date | 2006-02-23 |
United States Patent
Application |
20060039748 |
Kind Code |
A1 |
Ruhlander; Gregory P. |
February 23, 2006 |
Arrangement for connecting a rod end to a headed pin and method of
manufacture
Abstract
An arrangement and method of manufacture for providing a
connection between one end of a control rod and a headed pin
includes a hard plastic housing having a pin receiving cavity
defined therein, the housing overmolded over the rod end and a soft
elastomeric vibration isolator to hold the same together without
assembly clearances or subjecting the vibration isolator to direct
pressure from the pin to avoid excessive lash in the connection.
Retention prongs are integrally molded and configured to engage the
head of the pin when inserted in the cavity to be deflected to
allow assembly and thereafter resist extraction, with the insertion
forces much lower than the extraction force.
Inventors: |
Ruhlander; Gregory P.;
(Hannibal, MO) |
Correspondence
Address: |
John R. Benefiel
Suite 100B
280 Daines Street
Birmingham
MI
48009
US
|
Family ID: |
30118598 |
Appl. No.: |
10/449744 |
Filed: |
May 30, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60386986 |
Jun 7, 2002 |
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60400082 |
Jul 31, 2002 |
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Current U.S.
Class: |
403/122 |
Current CPC
Class: |
F16C 1/14 20130101; F16C
2361/65 20130101; Y10T 403/32803 20150115; Y10T 403/5773 20150115;
B60G 2206/11 20130101; F16C 1/108 20130101; Y10T 403/32951
20150115; Y10T 403/32631 20150115; Y10T 403/32786 20150115; B60G
2204/416 20130101; Y10T 403/69 20150115; F16C 11/04 20130101; Y10T
403/32795 20150115; F16C 2226/74 20130101 |
Class at
Publication: |
403/122 |
International
Class: |
F16C 11/00 20060101
F16C011/00 |
Claims
1. An arrangement for connecting a one end of a control rod to a
headed pin to enable driving of said pin by motion of said control
rod, in combination with said control rod and said headed pin,
comprising: a housing made of a hard plastic and defining a pin
receiving cavity, with one or more retention features projecting
into said cavity and engaging said headed pin when inserted therein
so as to be retained therein; a vibration isolator made of an
elastic material softer than said housing, said vibration isolator
fit over said one end of said control rod; and said housing
overmolded onto said vibration isolator join together said housing,
said one end of said rod, and said vibration isolator.
2. (canceled)
3. (canceled)
4. (canceled)
5. The arrangement according to claim 1 wherein said one end of
said rod has a groove formed therein, and said vibration isolator
is fit into said groove, and said housing overmolded onto an
annular feature formed on the exterior of said vibration
isolator.
6. The arrangement according to claim 5 wherein said vibration
isolator has a wall thickness on the order of one millimeter.
7. (canceled)
8. (canceled)
9. (canceled)
10. The arrangement according to claim 1 wherein said one or more
retention features comprise one or more prongs projecting into said
cavity and having radially deflectable portions able to be
deflected by a headed portion on said pin and allow passage into
said cavity, said head of said pin after passage into said
cavity.
11. The arrangement according to claim 10 wherein said prongs are
each formed with an axially extending base wall radially spaced
from a core structure portion and also having a lip, projecting
inwardly from said wall, and having a sloping under surface to be
engaged by said head on said pin to cause said radial deflection of
said associated prong, and a flat surface engaging said head after
said pin head has been inserted past said prongs to retain said pin
in said cavity.
12. The arrangement according to claim 1 further including a web
integrally molded into said housing extending over said cavity on
one side to prevent insertion of said pin from said one side.
13. A method of constructing a driving connection between one end
of a control rod and a headed pin, comprising the steps of: molding
a hard plastic housing to extend over said one end of said control
rod; forming a cavity in our within said housing offset from said
one end of said rod and configured to receive said headed pin;
forming at least one feature within said cavity engaging said
headed pin upon insertion therein to retain the same; interposing
an elastomeric vibration isolator softer than said hard plastic
housing between said hard plastic housing defining said cavity and
said one end of said rod and overmolding said housing onto said
vibration isolator when molding said housing to thereby join
together said housing, said one end of said rod and said vibration
isolator.
14. The method according to claim 13 wherein said step of forming
said cavity is included in the step of molding said housing.
15. The method according to claim 14 further including the steps of
locating said vibration isolator on said one end of said rod and
overmolding said housing over said vibration isolator on said
rod.
16. The method according to claim 15 further including the step of
molding said vibration isolator as a tubular structure disposed
over said one end of said rod prior to overmolding said housing
onto said vibration isolator.
17. (canceled)
18. The method according to claim 16 wherein in said step of
molding said vibration isolator to said one end of said rod, said
vibration isolator is formed with a thin wall on the order of one
millimeter in thickness.
19. The method according to claim 13 wherein said step of forming
at least one retention feature comprises the step of molding a
plurality of integral prongs in said hard plastic housing extending
radially inward into said cavity configured to engage a head
portion of said pin and be deflected radially outward thereby to
allow passage of said head portion and to thereafter engage said
head portion to retain the same in said cavity.
20. The method according to claim 19 wherein said prong molding
step includes forming a sloping under surface on said prongs to aid
in producing radial outward deflection by passage of said pin head
portion, and a flat surface on the end thereof engaging said pin
head portion to resist extraction whereby a much greater force is
required for extraction than for insertion of said pin.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. provisional
applications Ser. No. 60/386,986, filed Jun. 7, 2002 and Ser. No.
60/400,082, filed Jul. 31, 2002.
BACKGROUND OF THE INVENTION
[0002] This invention concerns rod end terminal connections
commonly used to connect control rods to pins mounted to automobile
transmission levers and the like to enable shifting of the
transmission by the driver of the automobile. The pin is retained
in a housing by a ball feature head on the pin snap fit to
retention features on the housing. It has become standard practice
to interpose a vibration isolator between the connected rod and pin
to prevent vibrations from being felt by the driver when grasping a
shifter or other member. See U.S. Pat. No. 4,581,953 for an example
of such a connection.
[0003] The vibration isolator is usually constructed of a soft
compressible material and excessive lash can result if the isolator
material is directly contacted by the pin.
[0004] Such connections have been provided by assembling several
parts together, and the necessary clearances for assembly also
contribute to excessive lash at the connection.
[0005] The cost of manufacturing such linkages typically is high
due to the need to assemble several components, and the need to
insure that proper assembly of the components has been
accomplished.
[0006] Another difficulty is encountered in designing the usually
snap fit assembled pin and rod connection so that the force to
assemble the connection must be low while the force resisting
disconnection of the components must be much higher.
[0007] It is the object of the present invention to provide an
arrangement for providing a connection between a pin and control
rod including a vibration isolator which minimizes lash between the
connected components.
[0008] It is a further object to provide such an arrangement which
can be manufactured at low cost.
[0009] It is yet another object to provide a snap fit pin-rod
connection in which a desired greater separation force and lesser
assembly force can be easily designed for.
SUMMARY OF THE INVENTION
[0010] These and other objects which will become apparent upon a
reading of the following specification and claims are achieved by
an arrangement for establishing a rod end terminal connection
having a vibration isolator of minimal thickness interposed between
the rod and an overmolded minimally compressible hard plastic
housing capturing the rod end and a vibration isolator interposed
between the rod end and a pin receiving cavity defined by a hard
plastic structure enclosed within the housing. Preferably the
vibration isolator is itself overmolded onto the rod end, received
in grooves in the rod and to be securely locked thereto. The hard
plastic defined cavity is configured to receive the pin and a
plurality of integral arcuate prongs are arranged about the inside
of the cavity. The prongs are readily deflectable outwardly
engagement of the head of the pin with sloping prong surfaces to
accommodate insertion of the pin, but pin movement out is resisted
by flat prong ends which requires application of a desired high
extraction force to deflect the prongs and allow removal of the
pin.
[0011] The overmolding of the hard plastic housing eliminates
assembly of separate parts as well as eliminating clearances and
lash resulting from having separate parts. The housing opening has
an overlying web blocking entrance of the pin into the cavity from
the wrong side to insure insertion of the pin into the housing from
the prior side.
DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a perspective view of an arrangement for
establishing rod end head pin connection according to the
invention.
[0013] FIG. 2 is a plan view of the arrangement shown in FIG. 1
with a fragmentary view of a rod end.
[0014] FIG. 3 is a vertical sectional view taken through the rod
end terminal connection shown in FIG. 1.
[0015] FIG. 4 is a horizontal sectional view taken through the rod
end terminal connection shown in FIG. 1.
[0016] FIG. 5 is a fragmentary partially sectional perspective view
from one side of the connection and mated pin shown in FIGS.
1-4.
[0017] FIG. 6 is a fragmentary partially sectional endwise
perspective view of the connection shown in FIGS. 1-5.
[0018] FIG. 7 is a fragmentary plan view of a connection with a
mating pin according to a second embodiment of the invention.
[0019] FIG. 8 is a view of a vertical section through the
connection shown in FIG. 1.
[0020] FIG. 9 is a plan view of an assembled inner core piece and
vibration isolator components included in the connection shown in
FIGS. 7 and 8.
[0021] FIG. 10 is a side elevational view of the assembled inner
piece core and vibration isolator components shown in FIG. 9.
[0022] FIG. 11 is a perspective view of the inner core and
assembled isolator components shown in FIGS. 9 and 10.
[0023] FIG. 12 is a perspective fragmentary view of the rod and
terminal connection and mating pin shown in FIGS. 7 and 8.
DETAILED DESCRIPTION
[0024] In the following detailed description, certain specific
terminology will be employed for the sake of clarity and a
particular embodiment described in accordance with the requirements
of 35 USC 112, but it is to be understood that the same is not
intended to be limiting and should not be so construed inasmuch as
the invention is capable of taking many forms and variations within
the scope of the appended claims.
[0025] Referring to the drawings, and particularly FIGS. 1-6, the
present invention provides an arrangement for establishing a
connection between a headed pin 10 and one end of a steel control
rod 12. Such connections are commonly used to couple a transmission
control rod to an automotive transmission lever by a pin allowing
relative rotation. Other control linkage systems for automotive and
other applications widely use such connections which allow a
changing angle of the control rod on the pin as it is advanced
retracted.
[0026] This connection includes a thin walled (approximately 1 mm
thick) soft elastomeric vibration isolator 14 preferably molded in
place onto the one end of the control rod 12, with a recess 16 on
the one end of the rod 12 keying the vibration isolator 14 to
insure retention thereon. The recess 16 also forms an annular
feature 17 in the vibration isolator. The vibration isolator 14
could also be separate molded and assembled onto the one end of the
control rod 12 (a suitable material is Bayer Desmopan 453 polyester
polyethylene based grade) Shore hardness scale 53D (ASTM
D2240).
[0027] A pin receiver housing 18 is molded over the vibration
isolator 14 and projects in a lengthwise direction away from the
one end of the rod 12 to offset a hard plastic structure defining a
pin receiving cavity 20 extending in a normal direction from the
longitudinal axis of the control rod 12.
[0028] A portion of the housing 18 is received into the annular
recess 17 formed in the vibration isolator 14 to be positively
keyed thereto for secure retention.
[0029] The housing 18 is molded from a hard plastic such as Dow
Vydyne R533 (Nylon 66% graphite filled (33%), Rockwell harness
scale M95 (ASTM D785).
[0030] A pair of pin retention features comprising arcuate prongs
22 are integrally formed on opposite sides of the cavity 20. Each
prong 22 includes an axially extending base wall 24 spaced inwardly
from the inside of the housing 18 to create a space allowing a
radially outward deflection thereof.
[0031] A radially inward projecting lip portion 26 extends from the
free end of the base wall 24, having a sloping undersurface 28 and
a flat end surface 30 at the top as viewed in the drawings.
[0032] The lower end of the cavity 20 is open while a web 32
extends there across at the top to provide an orientation feature
insuring correct assembly with the pin 10 able to be inserted only
from below as seen in the drawings.
[0033] The pin 10 has a spherical head 34 which when inserted into
the cavity 20 deflects the prongs 22 radially outward facilitated
by the sloping undersurface 28 of the prongs being cammed outwardly
by the spherically curving head 34. Integral ribs 23 limit outward
deflection of the prongs 22.
[0034] After the head 34 is inserted sufficiently, the head 34
passes lips 26 of the prongs 22 allowing the prongs 22 to snap back
to present the flat end face to the undersurface of the head
34.
[0035] A flange 38 on the pin 10 limits further insertion travel of
the pin 34 by engaging the bottom 40 of the housing 18.
[0036] The insertion force required to install the pin 10 is much
less than the force necessary to remove the pin 10 as a result of
the sloping undersurface 28 and the flat end face 30. By varying
the thickness of the wall 24, any particular insertion force
maximum and extraction force minimum can be designed for to meet
the application requirements. The wall 24 is placed in bending by
the camming out of the prongs 22 as the ball head 34 is
inserted.
[0037] The manufacturing process involves molding the vibration
isolator 14 to the one end of the rod 12.
[0038] The manufacturing steps are as follows:
[0039] This subassembly is then placed in a mold and housing 18 is
overmolded around the isolator-rod subassembly, the housing 18
having a portion located at one end of the rod 12 and formed with a
socket opening with radially inwardly projecting engagement prongs
for securing the pin. The housing 18 in being molded from a hard
plastic material, a low installation force for installing the pin
can be achieved compared with much higher extraction forces
required to separate the housing 18 from the pin 10.
[0040] The specific manufacturing process steps are as follows:
[0041] The vibration isolator 14 is installed around the end of the
steel rod 12. The groove 16 in the end of the rod 12 will match up
to an inner ridge on the isolator. The vibration isolator 14 is
molded around the end of the steel rod 12 with the groove and ridge
matching.
[0042] Once the vibration isolator 14 rod 12 subassembly is made,
molding of the final terminal assembly takes place. The vibration
isolator 14 rod 12 subassembly is placed in the mold into a
predetermined position. No special position for orientation is
needed. The prongs 22 and load feature of the housing 18 is then
molded to create the final assembly. This molding process
interlocks the vibration isolator 14 rod 12 subassembly with the
newly molded housing 18.
[0043] This connection and method provides several advantages. The
first is that the hard plastic housing 18 with engagement prongs 22
comprise a socket contacting the pin 10, allowing the design of the
prongs 22 to set the amount of installation and extraction force
desired. By changing the prong design, i.e., the thickness of the
wall, the amount of installation load required to secure the pin 10
can be reduced to meet any requirements and still maintain the
required minimum extraction force.
[0044] The second advantage is that by molding the housing 18
around the vibration isolator 14 and steel rod end, this will
provide increased strength to the rod end assembly and ensure that
the housing 18, vibration isolator 14, and steel rod 12 are
securely assembled. This design will also interlock these
components to eliminate any tolerance gaps between individual
parts. Prior designs had the possibility for tolerance gaps between
parts, which will cause free play in the system known as
"lash".
[0045] The third advantage is that the vibration isolator 14 is
wrapped around the steel rod 12 to avoid direct contact with the
pin 10. The vibration isolator 14 is molded with a small cross
section wall to lower the thickness of material subject to
compression. This will lower system lash and while still
maintaining adequate vibration dampening capabilities.
[0046] The fourth advantage is a reduction in manufacturing cost.
By molding the housing 18 over the vibration isolator/steel rod
subassembly there is a reduction in cost for manufacturing the
connection.
[0047] The fifth advantage is obtained by the addition of the
orientation feature 36 to the housing 18. By adding this feature
integrally the housing 18 can only go onto the pin 10 in one
direction. Previously this was done by installing a separate
component, increasing the cost of manufacture.
[0048] This design will make it easier to install on the vehicle,
reduces cost, and reduces the number of parts in the assembly.
[0049] The second embodiment is shown in FIGS. 7-12, in which a
hard plastic housing 38 is directly molded to one end of the
control rod 12.
[0050] The ring shaped vibration isolator 40 is assembled onto a
generally cylindrical hard plastic core piece 42 separately molded.
The housing 38 is molded over the vibration isolator 40. Thus, the
vibration isolator 40 does not directly contact the pin 10.
[0051] The core piece 42 has a central pin receiving cavity 46
formed with inwardly facing deflectable prongs 44 and orientation
feature 48 as in the first described embodiment.
[0052] A ridge 43 on the core piece 42 forms grooves 45 matching
grooves 47 on the vibration isolator 40 on the core piece 42 and,
together with a ridge 41 on the vibration isolator 40, these ensure
mutual retention to the overmolded housing 38.
[0053] The vibration isolator 40 is installed around the inner core
piece 42. The grooves 45 match up on both parts. The vibration
isolator 42 is fully assembled around the inner core piece 42 and
the grooves matched. Direction does not matter since the vibration
isolator 42 is symmetrical and will go on either direction.
[0054] The inner core piece subassembly is placed in the mold along
with the groove end of the steel rod 12. The inner core piece
subassembly is installed on a special pin in the mold. This special
pin correctly positions the inner core piece subassembly so that
the load path feature of the inner core piece 42 is in an axial
line with the steel rod 12. This will insure that the contact
prongs 44 will be positioned 90 degrees to the steel rod 12.
[0055] Once the inner core piece subassembly is in place, the steel
rod 12 is placed in the mold. The rod 12 is positioned so that the
rod end contacts the ridge 43 vibration isolator 40. This will
serve as a position stop for the steel rod 12. This stop feature
will make it easier for the operator to properly place the steel
rod 12 for the final molding.
[0056] Once the steel rod 12 and the inner core piece subassembly
are correctly in place, the outer housing 38 is molded over these
two other components. This molding process interlocks the inner
core piece subassembly and the steel rod to form the final terminal
rod assembly.
* * * * *