U.S. patent application number 12/544712 was filed with the patent office on 2011-02-24 for method for the fabrication of a screw member for plate member fastener.
Invention is credited to Kuo-Chung WANG.
Application Number | 20110045915 12/544712 |
Document ID | / |
Family ID | 43605804 |
Filed Date | 2011-02-24 |
United States Patent
Application |
20110045915 |
Kind Code |
A1 |
WANG; Kuo-Chung |
February 24, 2011 |
METHOD FOR THE FABRICATION OF A SCREW MEMBER FOR PLATE MEMBER
FASTENER
Abstract
A method for making a screw member for plate member fastener is
disclosed to include the step of preparing a metal element subject
to a predetermined size and then processing the metal element
through a cold extrusion forging operation to form a head at one
end, a connection portion at an opposite end and a shank between
the head and the connection portion, the step of processing the
connection portion through a thread rolling operation to form
threads around the periphery, the step of processing the threads to
form a stop end edge at one side in proximity to the shank, and the
step of finishing the final product.
Inventors: |
WANG; Kuo-Chung; (Yunlin
County, TW) |
Correspondence
Address: |
Muncy, Geissler, Olds & Lowe, PLLC
4000 Legato Road, Suite 310
FAIRFAX
VA
22033
US
|
Family ID: |
43605804 |
Appl. No.: |
12/544712 |
Filed: |
August 20, 2009 |
Current U.S.
Class: |
470/10 |
Current CPC
Class: |
B21H 3/06 20130101; B21K
1/46 20130101; B21K 1/56 20130101 |
Class at
Publication: |
470/10 |
International
Class: |
B21K 1/56 20060101
B21K001/56 |
Claims
1. A method for making a screw member for plate member fastener,
the method comprising the steps of: (a) Prepare a metal element
subject to a predetermined size, and then process said metal
element through a cold extrusion forging operation to form a head
at one end, a connection portion at an opposite end and a shank
between said head and said connection portion. (b) Process said
connection portion through a thread rolling operation to form
threads around the periphery of said connection portion (c) Process
said threads to form a stop end edge at one side in proximity to
said shank. (d) Finish the final product.
2. The method of claim 1, wherein the step (a) is to put the
prepared metal element put in between an upper die and a bottom die
of a forging machine for enabling the metal element to be forged to
form the desired shank and the desired connection portion, and then
to attach a hammer forging die to one end of the metal element
outside the upper die and the bottom die and to hammer the hammer
forging die in forging the respective end of the metal element into
the desired head.
3. The method of claim 1, wherein the step (b) is to put the
shape-formed metal element thus obtained from the step (a) in
between a thread rolling face of a first flat thread rolling die of
a first thread rolling die set of a thread rolling machine and a
thread rolling face of a second flat thread rolling die of said
first thread rolling die set of said thread rolling machine, and
then to reciprocate the first flat thread rolling die and second
flat thread rolling die of said first thread rolling die set in
reversed directions so as to form the desired threads around the
periphery of the connection portion.
4. The method of claim 3, wherein the step (c) is to put the
semi-finished screw member thus obtained from the step (b) in
between a first flat thread rolling die of a second thread rolling
die set of said thread rolling machine that has a thread rolling
face at one side thereof and an end edge-forming face suspending in
the thread rolling face and a second flat thread rolling die of
said second thread rolling die set that has a thread rolling face
at one side thereof, and then to reciprocate the first flat thread
rolling die and second flat thread rolling die of said second
thread rolling die set in reversed directions in forcing the
respective thread rolling faces against the connection portion of
the semi-finished screw member and causing said flat end
edge-forming face to cut an end portion of one last thread of the
threads of the semi-finished screw member into the desired stop end
edge.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention:
[0002] The present invention relates to a plate member fastener
fabrication method and more particularly, to a method for making a
screw member for plate member fastener that raises reliability of
the use of the plate member fastener.
[0003] 2. Description of the Related Art:
[0004] When fastening plate members together, a positioning screw
formed of a knob, a ring and a screw nail is usually used. During
installation, the screw nail and the ring are secured to the first
plate member, and then the knob is rotated to drive the screw nail
into the second plate member, and then a hand tool is used to
fasten tight the screw nail, affixing the first and second plate
members together. This plate member joining method can be used in a
machine tool to join plate members together.
[0005] The power drive or speed-adjustment unit of a machine tool
is provided inside the housing. To facilitate repair of the machine
tool or adjustment of the output speed of the machine tool, a
detachable plate member is usually provided at the housing of the
power drive or speed-adjustment unit. Screw bolts are commonly used
to fasten the movable plate member to the housing. When unfastening
screw bolts to dismount a movable plate member from the housing,
the associating lock nuts may fall from the screw bolts.
[0006] There is known a plate member fastener comprised of a cap, a
screw member, a spring member and a locating base for joining two
metal plate members together. After fixation of the locating base
of the plate member fastener to a through hole on a first plate
member, the screw member is threaded into a screw hole on a second
plate member to secure the first plate member and the second plate
member together. Because the locating base of the plate member
fastener is kept secured to the first plate member after removal of
the first plate member from the second plate member, the plate
member fastener will not be missed by accident. According to this
design, the screw member A, as shown in FIG. 9, has a head A1, a
shank A2 perpendicularly extended from the center of the bottom
side of the head A1 and a connection portion A3 axially extended
from the bottom end of the shank A2 remote from the head A1. The
connection portion A3 has an outer thread A31 spirally extending
around the periphery. The outer thread A31 has a reduced end
portion A311. During installation, the outer thread A31 of the
connection portion A3 is threaded into the screw hole on the second
metal plate member (not shown). When the reduced end portion A311
of the outer thread A31 reaches the inner thread of the screw hole
of the second metal plate member, the first metal plate member and
the second metal plate member are firmly secured together. If the
operator continuously rotates the head A1 of the screw member A at
this time, the reduced end portion A311 of the outer thread A31
will be threaded into the screw hole of the second metal plate
member, causing the screw member A to be stuck in the screw hole of
the second metal plate member. Therefore, when threading the screw
member A into the screw hole of the second metal plate member, the
rotary driving force must be properly controlled to avoid
overthreading.
[0007] Further, the reduced end portion A311 of the outer thread
A31 slopes in one direction. When the spring member is sleeved onto
the screw member A and stopped between the reduced end portion A311
of the outer thread A31 and the bottom side of the head A1, the
spring member may bias. When the screw member A, the cap and the
locating base are assembled, the cap and the locating base may be
not kept in perfect alignment. Small deviation of the component
parts may increase the difficulty of the installation of the plate
member fastener.
[0008] Accordingly, there is a strong need for plate member
fastener that overcomes the aforementioned and other deleterious
effects of the prior art plate member fastener.
SUMMARY OF THE INVENTION
[0009] The present invention has been accomplished under the
circumstances in view. It is therefore the main object of the
present invention to provide a method for the fabrication of a
screw member for plate member fastener, which facilitates mounting
and dismounting of the plate member fastener, avoiding
overthreading during installation.
[0010] A screw member fabrication method in accordance with the
present invention includes the steps of (a) preparing a metal
element subject to a predetermined size, and then processing the
metal element through a cold extrusion forging operation to form a
head at one end, a connection portion at an opposite end and a
shank between said head and said connection portion, (b) processing
the connection portion through a thread rolling operation to form
threads around the periphery of the connection portion, (c)
processing threads to form a stop end edge at one side in proximity
to the shank, and (d) finishing the final product. When the screw
member is used in a plate member fastener and threaded through a
mounting through hole on a first metal plate member into a
corresponding screw hole of a second metal plate member to secure
the first metal plate member and the second metal plate member
together, the stop end edge of the screw member avoids
overthreading, preventing sticking of the screw member in the
second metal plate member.
[0011] Further, the stop end edge is a flat edge extending in
direction perpendicular to the axis of the screw member. When the
screw member is used in a plate member fastener and a spring member
is sleeved onto the screw member and stopped between the bottom
side of the head and stop end edge of the screw member, the screw
member will not be forced to bias and can be accurately threaded
into the screw hole of the second metal plate member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is an exploded view of the plate member fastener in
accordance with the present invention.
[0013] FIG. 2 is a flow chart of the present invention showing the
fabrication of a screw member for plate member fastener in
accordance with the present invention.
[0014] FIG. 3 is a schematic sectional view, showing a metal
element set in forging dies of a forging machine according to the
present invention.
[0015] FIG. 4 is a schematic sectional view of the present
invention, showing the thread rolling operation (I).
[0016] FIG. 5 is a schematic sectional view of the present
invention, showing the thread rolling operation (II).
[0017] FIG. 6 is side view of a finished screw member according to
the present invention.
[0018] FIG. 7 is an exploded view in sectional elevation of the
present invention, showing the cap molded on the head of the screw
member.
[0019] FIG. 8 is a sectional view of the present invention, showing
the plate member fastener fastened to two metal plate members.
[0020] FIG. 9 is a side view of a screw member for plate member
fastener according to the prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] Referring to FIGS. 1 and 7, a plate member fastener in
accordance with the present invention comprises a cap 1, a screw
member 2, a barrel 3, and a spring member 4.
[0022] The cap 1 is a hollow member having a center opening 10
axially extending through the top and bottom sides for receiving
the barrel 3, the screw member 2 and the spring member 4, a
serrated inside retaining portion 11 arranged around the inside
wall near the top side for retaining the engagement portion 211 of
the screw member 2, and a grip 12 located on the periphery at the
top side for gripping by hand.
[0023] The screw member 2 is a metal member having a head 21, an
engagement portion 211 formed on the periphery of the head 21 for
engagement with the serrated inside retaining portion 11 of the cap
1, a shank 22 perpendicularly extended from the center of the
bottom wall of the head 21 and terminating in a connection tip 23,
threads 231 spirally arranged around the periphery of the
connection tip 23 and defining a stop end edge 2311 at a proximal
side relative to the shank 22, and a tool groove 24 located on the
top wall of the head 21. Further, the tool groove 24 can be a
Phillipes groove, keystone groove, asterisk groove or hex
groove.
[0024] The barrel 3 is a hollow cylindrical metal member having an
inside accommodation space 30 extending through top and bottom
sides thereof, a step 31 located on the inside around the inside
accommodation space 30, a locating groove 32 extending around the
inside wall inside the inside accommodation space 30 and abutted
against the bottom side of the step 31, a bottom extension tube 33
axially forwardly extended from the bottom side of the barrel 3,
and a bonding edge 331 defined on the bottom side of the barrel 3
around the bottom extension tube 33. Further, a retainer ring 34 is
secured to the periphery of the shank 22 of the screw member 2 and
positioned in the locating groove 32 inside the inside
accommodation space 30.
[0025] The spring member 4 is sleeved onto the screw member 2,
having a deformable coiled body 41 surrounding the shank 22 of the
screw member 2 and two end portions 42 respective disposed at the
two distal ends of the deformable coiled body 41.
[0026] Referring to FIGS. 2,3 4, 5 and 6, the screw member 2 is
made of a metal element 5 that can be a steel, iron or stainless
steel ingot.
[0027] The screw member 2 is made subject to the following steps:
[0028] 100 Prepare a metal element 5 subject to a predetermined
size. [0029] 101 Process the metal element 5 through a cold
extrusion forging operation to form the desired head 21, shank 22
and connection portion 23. [0030] 102 Process the connection
portion 23 through a thread rolling operation to form the desired
threads 231. [0031] 103 Process the threads 231 to form the desired
stop edge 2311 at one side in proximity to the shank 22. [0032] 104
Finish the desired screw member 2.
[0033] The metal element 5 is extruded into the desired length and
width through a cold extrusion operation, and then processed
through a cold forging process to form the desired head 21, shank
22 and connection portion 23. The cold extrusion forging operation
is described hereinafter. After extrusion through a cold extrusion
operation, the metal element 5 is put in between an upper die 61
and a bottom die 62 of a forging machine 6, and then forged to form
the desired shank 22 and connection portion 23, and then a hammer
forging die 63 is attached to one end of the metal element 5
outside the upper die 61 and the bottom die 62 and hammered to
forge the respective end of the metal element 5 into the desired
head 21. Thereafter, the shape-formed metal element 5 thus obtained
is put in between the thread rolling faces 7111 and 7121 of the two
flat thread rolling dies 711 and 712 of a first thread rolling die
set 71 of a thread rolling machine 7, and then the two flat thread
rolling dies 711 and 712 are reciprocated relative to each other to
force the respective thread rolling faces 7111 and 7121 against the
connection portion 23, thereby forming a semi-finished screw member
2 having the desired threads 231 around the periphery of the
connection portion 23. Thereafter, the semi-finished screw member 2
thus obtained is put in between the thread rolling faces 7211 and
7221 of the two flat thread rolling dies 721 and 722 of a second
thread rolling die set 72 of the thread rolling machine 7 wherein
one flat thread rolling dies 721 has a top mounting groove 7213
located on the top wall 7210 thereof and an end edge-forming block
7212 affixed to the top mounting groove 7213 with a flat end
edge-forming face 7214 thereof suspending in the thread rolling
face 7211, and then the two flat thread rolling dies 721 and 722 of
the second thread rolling die set 72 are reciprocated relative to
each other to force the respective thread rolling faces 7211 and
7221 against the connection portion 23, causing the flat end
edge-forming face 7214 to cut the end portion 2311 of the last
thread 231 of the semi-finished screw member 2 so that a finished
screw member 2 having the desired stop end edge 2311 at the end of
the set of threads 231 in proximity to the shank 22 is thus
obtained. When the screw member 2 is threaded into the screw hole
821 of a second metal plate member 82 during the use of the plate
member fastener to secure a first metal plate member 81 to the
second metal plate member 82, the stop end edge 2311 will be
stopped against the inner threads 8211 to prohibit forward
rotation, avoiding overthreading of the screw member 2 (see FIG.
8). Further, the flat end edge-forming face 7214 may be directly
formed integral with the thread rolling face 7211 of the flat
thread rolling die 721, or the end edge-forming block 7212 may be
separately made and then inserted into the flat thread rolling die
721.
[0034] Referring to FIG. 7, the screw member 2 made subject to the
aforesaid fabrication method is fastened to the cap 1, and then the
spring member 4 is sleeved onto the screw member 2, and then the
retainer ring 34 is fastened to the screw member 2 to secure the
barrel 3 to the screw member 2 in the cap 1.
[0035] Further, the cap 1 can be directly molded on the head 21 of
the screw member 2 with over-molding technology. After molding, the
engagement portion 211 of the head 21 of the screw member 21 that
can be formed of a series of barbs, teeth or protruding ribs is
formed integral with the serrated inside retaining portion 11 of
the cap 1. Thereafter, the spring member 4 is inserted into the
center opening 10 of the cap 1 to sleeve the deformable coiled body
41, and then the barrel 3 is inserted into the center opening 10 of
the cap 1 to have the screw member 2 and the spring member 4 be
accommodated in the inside accommodation space 30 and the two end
portions 42 of the spring member 4 be respectively stopped the
bottom side of the head 21 of the screw member 2 and the step 31 of
the barrel 3. Further, the retainer ring 34 is fastened to the
periphery of the shank 22 of the screw member 2 and positioned in
the locating groove 32 inside the barrel 3.
[0036] Referring to FIG. 8, during application of the present
invention to fasten a set of metal plate members 8, an automatic
installation machine is used to pick up the plate member fastener
and then to insert the bottom extension tube 33 of the barrel 3 of
the plate member fastener into the mounting through hole 811 of the
first metal plate member 81 and to attach the bonding edge 331 of
the barrel 3 to the solder paste 812 that was applied to the border
area of the mounting through hole 811 of the first metal plate
member 81, and then a reflow soldering process is applied to have
the barrel 3 be bonded to the first metal plate 81.
[0037] After installation of the barrel 3 in the first metal plate
member 81, attach the first metal plate member 81 to the second
metal plate member 82 to aim the screw member 2 at the screw hole
821 of the second metal plate member 82, and then force the cap 1
downwards and rotate the cap 1 to drive the outer thread 231 of the
screw member 2 into the screw hole 821 of the second metal plate
member 82, and then attach a hand tool (for example, screwdriver)
to the tool groove 24 of the screw member 2 and rotate the hand
tool to tighten up the connection between the screw member 2 and
the second metal plate member 82. Thus, the first metal plate
member 81 and the second metal plate member 82 are firmly secured
together by the plate member fastener. By means of the effect of
the stop end edge 2311, the invention avoids overthreading of the
screw member 2 and facilitates disconnection of the first metal
plate member 81 from the second metal plate member 82.
[0038] Further, the stop end edge 2311 of the screw member 2 is a
flat edge extending in direction perpendicular to the axis of the
screw member 2. Thus, when the spring member 4 is received in the
barrel 1 and the two end portions 42 are respectively stopped at
the bottom side of the head 21 and stop end edge 2311 of the screw
member 2, the screw member 2 will not be forced to bias and can be
accurately threaded into the screw hole 821 of the second metal
plate member 82.
[0039] While the present disclosure has been described with
reference to one exemplary embodiment, it will be understood that
the description of the exemplary embodiment is not a limitation of
the invention.
[0040] Although a particular embodiment of the invention has been
described in detail for purposes of illustration, various
modifications and enhancements may be made without departing from
the spirit and scope of the invention. Accordingly, the invention
is not to be limited except as by the appended claims.
* * * * *