U.S. patent number 3,918,286 [Application Number 05/515,501] was granted by the patent office on 1975-11-11 for u-bolt bending machine.
Invention is credited to Willard Whitehead.
United States Patent |
3,918,286 |
Whitehead |
November 11, 1975 |
U-Bolt bending machine
Abstract
A bending machine for bending elongate metal stock into curved
configurations. Two adjustably fixed spaced dies receive the stock
thereagainst while a movable die moves between the fixed dies
causing the metal to be bent into a curvature of up to
180.degree..
Inventors: |
Whitehead; Willard (Midland,
TX) |
Family
ID: |
24051627 |
Appl.
No.: |
05/515,501 |
Filed: |
October 17, 1975 |
Current U.S.
Class: |
72/213;
72/389.8 |
Current CPC
Class: |
B21D
7/06 (20130101); B21D 11/10 (20130101) |
Current International
Class: |
B21D
7/00 (20060101); B21D 11/00 (20060101); B21D
11/10 (20060101); B21D 7/06 (20060101); B21D
007/03 () |
Field of
Search: |
;72/212,213,389,400,381,386,214,220,418,456 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Mehr; Milton S.
Attorney, Agent or Firm: Bates; Marcus L.
Claims
I claim:
1. In a bending machine for bending metal stock to produce U-bolts
and the like, a longitudinally extending table having a
longitudinally extending slot formed therein;
an elongated slidable power member underlying said slot, means
slidably capturing said power member to said table in a slidable
and abutting manner to slidably engage abuting surfaces of said
power member and said table;
a mandrel attached to said power member and having a free marginal
end portion extending through said slot; a movable die affixed to
the marginal free end portion of said mandrel;
spaced fixed dies equally spaced apart and from said movable
die;
spaced arms pivotally secured to said table and having a swingable
end to which there is attached said fixed die;
means for reciprocating said power member to move said mandrel
along said slot to cause said movable die to move between said
fixed dies;
so that the central marginal length of a piece of metal stock
placed against said fixed dies can be engaged by said movable die
and bent into a curved configuration.
2. The machine of claim 1 wherein said pivoted end of said spaced
arms are adjustably secured to one another by a tie rod;
means for adjusting the effective length of said tie rod, thereby
enabling selection of the distance between said fixed dies.
3. The machine of claim 2 wherein said fixed dies include means
rotatably securing them in fixed relationship to said arm.
4. The machine of claim 1 wherein said power member is a
rectangular member, and said means slidably capturing said power
member is opposed downwardly depending web members which form said
table into a monocoque configuration, the lowermost marginal
longitudinally extending edge portion of said web members being
inwardly turned for bottom supporting said power member
therefrom.
5. The machine of claim 1 wherein said means for reciprocating said
power member is a hydraulic cylinder, and biasing means are
attached between said power member and said table for returning
said power member to a position of rest;
a fixed ear downwardly attached to said table, a pin received
through said ear and the cylinder of said hydraulic unit, a movable
ear downwardly attached to said power member, a pin received
through said ear and the piston of said hydraulic unit,
said biasing means affixed to said pins and biasing them toward one
another.
6. In a machine for bending a bendable member such as rods, bars,
tubes, u-bolts, and the like, the combination comprising a
stationary plate member having a longitudinally disposed slot
formed therein, a mandrel received through said slot and movable
longitudinally along the length thereof, a bending die affixed to
said mandrel and movable therewith;
a power member underlying said plate member, means moving said
power member along the length of said slot, said mandrel being
affixed to said power member and movable therewith;
a pair of spaced arms located on either side of the slot, each said
arm is pivotally secured to said plate member, means forming a
fixed die at one end of each arm, means by which said fixed dies
may be moved toward one another, said fixed dies being arranged
respective to said bending die so that the latter is moved through
the former by the action of said power member;
so that the bendable member can be placed with the fixed and
bending dies arranged on opposite sides thereof, the power member
moved along the slot, thereby causing the dies to engage and deform
the bendable member into a bent configuration.
7. The combination of claim 6, wherein said mandrel is removably
affixed to said power member; and, said bending die is removably
affixed to said mandrel; said bending die having a flat leading
edge portion bounded on either side thereof by a curved trailing
surface, with the curved trailing surface having a radius of
curvature substantially equal to the radius of curvature desired of
the bent member.
8. The combination of claim 6 wherein said bending die is a
cylindrical member except for the leading edge portion thereof
which is made into a flat surface for initially contacting the
bendable member.
9. The combination of claim 6 wherein said bending die has a
cylindrical geometrical configuration with the leading edge portion
thereof being flat so that the flat leading edge portion first
contacts the bendable member and thereafter the spaced curved
portion of the cylinder contacts the bendable member.
10. The combination of claim 6 wherein said power member is an
elongated square piece of metal stock, means slidably capturing
said power member in underlying abutting relationship respective to
the lower surface of said plate member;
said means for moving said power member being a hydraulic cylinder
interposed between the plate member and the power member;
and further including means for controlling the action of said
hydraulic cylinder so that the poiston thereof reciprocates in
either of its two directions of movement.
Description
THE PRIOR ART
The U.S. Pat. Nos. to Kroetch 3,724,256; Denninger 3,610,019; Hutch
3,429,157; and, Shaw Jr. 3,260,091 are examples of the known prior
art.
BACKGROUND OF THE INVENTION
Bending machines for fabricating U-bolts and the like are known as
examplified by the above referred to prior art patents. It is often
desirable for small machine shops and fabrication shops to be able
to bend tubular stock into a radius of curvature up to 180.degree.,
as for example the making of a U-bolt. Such a desirable expedient
avoids carrying a large and expensive inventory, but also enables
the most optimum choice of material since the exact desired part
can be fabricated at once, thereby effecting a savings in both time
and money.
It is desirable that such a machine be low in cost, simple to
operate, and efficient in operation.
SUMMARY OF THE INVENTION
A bending machine for bending elongated metal stock into a curve
having a radius of curvature up to 180.degree.. Two pivoted arms
carry fixed dies at the pivoted end thereof, with the dies being
adjustably disposed in spaced relation to one another. The arms are
supported from a table.
A movable die is mounted to a power member by means of a mandrel
with the mandrel being brought through a slot in the table so that
the table can form the main support structure for all of the
apparatus.
The movable die is forced to pass between the fixed dies, thereby
causing any stock placed therebetween to be bent according to the
configuration of the movable die and the extent of relative
movement between the fixed and movable dies.
Accordingly, a primary object of this invention is the provision of
a bending machine for forcing elongated metal stock into a
non-linear configuration;
Another object of the invention is to provide a bending machine for
use in fabricating U-bolts from elongated metal stock.
A further object of this invention is to provide a bending machine
in which spaced fixed dies and a movable die cooperate together in
a novel manner to provide a U-bolt in an unexpected manner.
A still further object of this invention is to provide a bending
machine which is simple to operate, low in initial cost, safe in
operation, and efficient in design.
The above objects are attained in accordance with the present
invention by the provision of a combination of elements which are
fabricated in a manner substantially as described in the above
abstract and summary.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of apparatus made in accordance with
the present invention;
FIG. 2 is a diagrammatical, part schematical representation of an
important principal of operation of the present invention;
FIG. 3 is a broken, part cross-sectional representation which sets
forth some of the details of the invention;
FIG. 4 is a longitudinal, part cross-sectional view which sets
forth some important details of the present invention, with some
parts being broken away to more clearly illustrate what lies
therebeyond;
FIG. 5 is a top plan view of apparatus disclosed in the foregoing
figures, with parts being broken away therefrom to disclose
important aspects of the invention;
FIG. 6 is an end view of the apparatus disclosed in FIG. 5;
FIG. 7 is an enlarged detailed top view of part of the apparatus
disclosed in FIGS. 5 and 6;
FIG. 8 is an enlarged detail taken along line 8--8 of FIG. 7;
FIG. 9 is a bottom view looking along the arrows indicated by line
9--9 of FIG. 8;
FIG. 10 is a side elevational view of another form of the
invention; and,
FIG. 11 is a bottom view taken along line 11--11 of FIG. 10.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Throughout the figures of the drawing, wherever possible, like or
similar numerals will refer to like or similar elements thereof. In
the figures of the drawing there is disclosed a U-bolt bending
machine 10 comprised of a reinforced table 12, a bending die 14
which moves relative to table 12, a roller die 16 spaced from a
second roller die 17 with the dies being adjustably mounted in
fixed relation respective to one another and to the table. A
longitudinally extending marginal portion of a rod having the
marginal opposed ends thereof threaded and placed in the
illustrated manner of FIG. 2a so that opposed ends L1, L2 of the
rod are bent toward one another as axis C1 and C2 move through one
another.
As particularly seen in FIG. 2a, the roller dies 16 and 17 are
disposed along axes C1 with the threaded rod 18 having a marginal
portion 19 abuttingly engaged with an outer peripheral wall surface
of the roller dies. The rod also engages a flat leading edge
portion 15 of the central die 14.
In FIG. 2b axis C1 and C2 remain parallel and are forced to move
toward one another thereby breaking the central marginal portion 19
of the rod into the beginning of a radius of curvature seen
illustrated at 19' in FIG. 2b and 119 in FIG. 2c.
As seen in FIG. 3, a mandrel 20 has a lower end portion 22 and an
opposite upper end portion, the latter being provided with a
vertical index key 23 and the former being provided with a
horizontal index key 24. As seen in FIG. 7, a keyway 26 is cut into
the movable die. The outer peripheral surface 27 of the movable die
ordinarily circumferentially extends in a manner as indicated by
the dot-dashed area 27'. The leading edge of the die is provided
with a vertically disposed face 28 for initially engaging stock 19.
Numeral 29 indicates the bending configuration of stock 19 in the
absence of face 28 being formed into the leading edge portion of
the die.
On FIGS. 3, 4, and 8, it will be noted that power member 30 has a
counterbore 32 formed therein complementary respective to members
20 and 24 so that the mandrel is always arranged in indexed
relationship therewith. Elongated slot 34 is formed longitudinally
respective of the table so that the mandrel can be moved within the
slot and longitudinally respective of the table.
Spaced arms in the form of adjustment plates 36 and 37 are spaced
from one another and pivotally secured to the table by means of
pivot pins 38 and 39 thereby enabling the positioning pins 40 and
41 to be moved toward and away from one another when handle 42
rotates threaded member 43. Member 43 threadedly engages member 41
while the free marginal end 42 is journaled to the pin 40. The
rotatable fixed dies and therefore positioned at the pivoted or
swingable end of the arms. Handle 46 cooperates with the
illustrated arcuate slotted member 50 to provide a friction lock
for member 36. Member 37 requires no friction lock for reasons
which will be better appreciated later on in the disclosure.
The before mentioned power member 30 has opposed end portions 52
and 54. The member is slidably captured within L-shaped web members
56 and 58 so that the power member can slide in low friction
relationship longitudinally of the table an amount which enables
full travel of the mandrel along the length of slot 34.
As seen in FIGS. 3 and 4, a centrally located downwardly depending
member 60, also called an "ear," is rigidly affixed to the marginal
forward end portion of member 30 and has rigidly affixed thereto a
pin 62 which has opposed ends arranged normally thereto. Cylinder
64 of a hydraulic unit has a piston 66 thereof journaled to the
before mentioned pin, with the cylinder being journaled to pin 68.
Biasing means in the form of opposed springs 70 and 71 are arranged
on opposed sides of the hydraulic unit and have the depending ends
thereof affixed to the pins 62 and 68, thereby forming a return
biasing means for the mandrel. Hence, the hydraulic unit
reciprocates the power member forward while the biasing means
reciprocates the power member in the opposite direction.
Spaced vertical webs 72 form a mounting means for pin 68 and is
rigidly affixed to the table and to the illustrated member 74.
Member 75 is attached to the table and provides additional support
for the apparatus.
Flow connection 76 is fluid connected to flow control valve 78
which in turn is connected to hydraulic pump 80 and to the
reservoir 82. Valve controller 79 can be engaged by the foot to
control the flow of hydraulic fluid to and from the cylinder 64.
Electric motor 81 is electrically connected to the motor controller
84 while switch 86 enables the entire apparatus to be
de-energized.
In operation, a suitable source of current is connected to the
controller and the switch 86 turned on, thereby causing induction
motor 81 to actuate the pump 80, thereby providing a source of
hydraulic pressure for the cylinder 64. When lever 79 is pushed in
a downward direction by the foot, valve 78 causes fluid to flow
into the cylinder 64 thereby moving piston 66 which in turn moves
pin 62, vertical webs 60, power member 30, and the mandrel 20
longitudinally within its slot.
Prior to moving the mandrel in a forward direction, the proper size
movable die is selected to provide a U-bolt having the proper
desired radius of curvature. The fixed roller dies are properly
positioned relative to one another so that the distance between the
spaced bolt engaging surfaces of the roller dies is exactly equal
to the measured distance between legs L1 and L2 of the finished
U-bolt. A threaded bar 19 is placed between the leading face 28 of
the die and abuttingly engages each of the rollers 16 and 17. The
piston is reciprocated within the cylinder by engaging valve
control rod 79 with the foot, thereby causing rollers 14, 16, 17 to
move relative to one another as illustrated in FIG. 2a, 2b, and
2c.
Applicant has discovered that by removing the area between 28 and
27' of the die 14, the bolt 19 will not creep forward into the
illustrated position 29 while it is being bent into a U-shape in
accordance with FIGS. 2a, 2b, and 2c. The presence of the flat face
or leading edge 28 causes the stock 19 to be bent into a perfect
radius of curvature 119 as axis C1 moves through axis C2. The
curvature 19' or 119 is controlled by the amount of material
removed between 27' and 28. Ordinarily, 15 percent to 40 percent of
the area of the die, viewed in plan, is is removed in order to
attain the desired configuration at 119.
The reason that the removal of the material at 28' results in a
radius of curvature 119 which coinsides with radius 27' of FIG. 7,
for example, is because the bolt is engaged by the outer periphery
27 of the die as the bending operation commences, and since the
bolt is originally deformed into an initial bend as a result of
being forced between the three dies, the marginal area of the bolt
is caused to assume an undesirable sharp bend seen illustrated at
29 in FIG. 2b. By engaging a larger surface area of the bolt by a
larger bearing area 28, a more uniform and desirable radius of
curvature 119 is achieved rather than an undesirable sharp bend
29.
Release of lever 79 causes the fluid flowing through pump 80 to
bypass the cylinder the flow to the reservoir 82, whereupon biasing
means 70 urges pins 62 and 68 toward one another, thereby returning
the mandrel to its initial position respective to the slotted
table. The apparatus is now in stand-by configuration awaiting
fabrication of the next U-bolt.
When it is deemed desirable to fabricate U-bolts of different
configurations, various different diameter dies can be substituted
for the one illustrated at numeral 14. For example, should a square
U-bolt be deemed desirable, the apparatus disclosed in FIGS. 10 and
11 can be employed in order to fabricate each 90.degree. bend of a
square U-bolt. The amount of bend imparted into a piece of stock
can be regulated by the distance traveled by the moving die
respective to the spaced fixed dies.
* * * * *