Note: Descriptions are shown in the official language in which they were submitted.
1301~i2
TUBE BENDER
Description
Technical Field
This invention relates to tube benders and in
5 particular to manually operable tube benders having a
pair of manually graspable handles for moving a bending
shoe relative to a bending mandrel.
Backqround Art
One improved form of manually operable tube bender
10 is disclosed in U.S. Letters Patent 3,685,335 of Leonard
J. Kowal. As shown therein, a mandrel is provided with a
peripheral arcuate groove into which a tube to be bent is
urged by a cooperating shoe. The shoe is swingably
mounted in association with the mandrel and is moved by
15 means of a handle extending outwardly therefrom. The
mandrel, in turn, is supported on a second handle rigidly
connected thereto, and in the tube forming operation, the
first handle is brought from a start position wherein it
extends generally perpendicularly to the second handle to
20 a final position wherein the grasping portion thereof is
disposed adjacent the grasping portion of the second
handle.
It is desirable to limit the swing of the first
handle so as to avoid a crossover between the handles in
25 effecting the desired bend. Such limitation restricts
the amount of movement of the shoe about the mandrel
groove. It has been proposed to incorporate, in the tube
bender, means for permitting the first handle to be
repositioned from the initial end position adjacent the
30 grasping portion of the first handle so as to permit a
further travel of the bending shoe about the mandrel by
effecting a subsequent movement of the first handle
similarly to the initial movement thereof between the
bend start location and the position adjacent the second
35 handle grasping means. Thus, a bend of up to 180 may be
~3016~2
effected with such structure without losing the desirable
leverage and thereby permitting the bending of relatively
rigid tubing.
U.S. Letters Patent 2,979,976 and 3,190,105 attempt
5 to provide this feature in the prior art. The benders
disclosed in these patents, however, suffer from the
problems of being complex in design and thus more expen-
sive to manufacture. Further, U.S. Patent 2,979,976
discloses a manual locking mechanism which is cumbersome
to use while U.S. Patent 3,190,105 discloses a bender
design in which the operation of repositioning the handle
requires more care and control.
Disclosure of Invention
The present invention comprehends a tube bender
lS having improved means for permitting repositioning of the
first handle when desired so as to permit extended bend-
ing of the tube in the mandrel groove, such as up to
approximately 18~.
The invention comprehends the provision of means
connecting the first handle to the shoe, permitting
swiveling thereof between any one of a plurality of
preselected positions, and in the illustrated embodiment,
the handle connecting means provides for two preselected
swiveled positions of the first handle relative to the
2S shoe.
The illustrated handle includes an end portion
rotatably received in a socket provided in the shoe. The
means for retaining the handle end in the socket further
defines the means for providing the preselected position-
ing of the handle.
In the illustrated embodiment, the grasping portionof the first handle extends at an angle of approximately
65 to the end portion received in the socket.
In the illustrated embodiment, the end portion of5 the first handle is rotatable 180 in the socket in
1:~016i2
providinq the two preselected positions of the grasping
portion of the handle.
Resiliently biased friction are provided for
retaining the first handle in either of the preselected
5 positions.
The means for connecting the first handle to the
shoe includes overcenter means for causing the first
handle to be effectively held in the selected preselected
disposition as a result of application of tube bending
10 force to the first handle.
The tube bender structure of the invention is
extremely simple and economical of construction, provides
automatic self-locking of the handle in the desired
dispositions, provides improved swiveling means for
15 extended useful life and esthetics, and provides con-
trolled, smooth operation in effecting the tube bend.
Brief Description of the Drawing
Other features and advantages of the invention will
be apparent from the following description taken in
20 connection with the accompanying drawing wherein:
FIGURE 1 is a side elevation of a tube bender
structure embodying the invention, with the handle con-
nected to the shoe being shown in different positions in
broken lines;
FIGURE 2 is a fragmentary enlarged side elevation,
with portions broken away illustrating the connection of
the handle to the shoe in greater detail;
FIGURE 3A is a fragmentary transverse section taken
substantially along the line 3-3 of Figure 2;
FIGURE 3B is a view similar to that of Figure 3A,
but with the handle in the dotted line position of Figure
2; and
FIGURE 4 is a fragmentary exploded side elevation of
the handle connecting means, with the shoe structure
35 omitted.
130161;~
Best ~leans for Carryinq Out the Invention
In the illustrative embodiment of the invention as
disclosed in the drawing, a tube bender generally desig-
nated 10 is shown to include a mandrel 11 having a pe-
ripheral tube bending groove 12 extending concentricallyabout an axis 13 of the mandrel.
A tube bending shoe 14 is swingably connected to the
mandrel by a link 15 for concentric movement about axis
13 in pressing a tube T to be bent progressively into the
groove 12 as a result of swinging of the shoe from a bend
start position 16 to a bend position 17 of approximately
90, as seen in Figure 1.
The present invèntion is concerned with providing
means for permitting the tube bender to be used in ex-
tending the tube bend beyond 90, such as up to approxi-
mately 180 with improved facility.
More specifically, the mandrel is fixedly secured to
an end 18 of a first handle 19 having a grasping portion
20 at the end opposite end 18. Shoe 16 is caused to move
about the mandrel by, means of a second handle 21 having
an end 22 connected to the shoe and a grasping portion 23
at the end opposite end 22.
Handle end 22 defines a longitudinal axis 24 and
grasping portion 23 defines a longitudinal axis 25. As
best seen 1n Figure 2, axis 25 extends at an angle of
approximately 115 to axis 24.
In the illustrated embodiment, handle end 22
includes an arcuate portion 26 and a rectilinear, distal
end portion 27. As seen in Figure 4, the handle is
tubular and a cylindrical extension 28 is fitted into the
distal end 27. Extension 28 is rigidly secured to the
handle end portion 27 by suitable crimping 29.
Adjacent its distal end 30, extension 28 is provided
with a chordal slot 31 extending approximately three-
quarters through the transverse extent of the extension.
130~612
The inner end 32 of slot 31 is arcuate and is adapted tosnugly receive a locking pin 33.
As best seen in Figure 2, handle extension 28 is
rotatably received in a cylindrical socket 34 in shoe 16
for rotation about axis 24. The shank 35 of pin 33
extends less than halfway through the extension slot 31,
as illustrated in Figures 3A and 3B. In swinging about
axls 24, bottom 32 of slot 31 is brought around the
distal end 36 of shank 35 so as to be selectively dis-
posed in the alternative positions of Figure 3A and 3B180 apart. In the illustrated embodiment, the rotation
is slightly more than 180 so as to dispose the handle
slightly over center in each of the preselected end
positions, whereby a force generated through the handle
in urging the shoe about the mandrel axis 13 in the
bending operation tends to lock the handle in the prese-
lected position.
The handle is further releasably retained in the
selected position by means of a spring washer 37 received
in the bottom of socket 34 and resiliently urging the
extension portion of the handle longitudinally outwardly
against the side of locking pin shank 35.
Pin 33 is force-fitting through the side of the
shoe, as illustrated in Figures 3A and 3B, and is pressed
25 in flush with the outside surface 38 for accurately
positioning the inner end 36 to permit maximum seating of
the extension 28 on the side of the pin n the selected
dispositions of Figures 3A and 3B, while yet permitting
the swinging of the slot end 32 around the distal end of
30 the pin.
As shown, the swiveling means is recessed within the
shoe for minimized maintenance requirements and long
troublefree life. That is, the swiveling means is pro-
tected from contamination and not open as in prior art
35 devices.
130~612
In use, the handle 21 is firstly arranged, as shown
in broken lines at the top of Figure 1, and the shoe 16
manipulated on link 15 to bring the shoe against the tube
T to be bent in groove 12 of the mandrel. Shoe 16 is
then swung about axis 13 of the mandrel by movement of
the handle 21 from the bend start position an angular
distance A to approximately a 90 bend position wherein
the handle grasping portion 23 is juxtaposed to the
grasping portion 20 of handle 19. To provide a bend of
10 over approximately 90, the user need merely swivel
handle 21 about the axis 24 of extension 28 so as to
bring the grasping portion 23 again back to adjacent the
original bend start position, whereupon further swinging
of the shoe about axis 13 of the mandrel may be effected
15 over the angle B to a final bend position illustrated in
full lines in Figure 1 and wherein the tube is bent
approximately 180, as shown therein.
While the handle 21 is effectively retained in the
preselected dispositions by the overcenter arrangement
20 during the bending operation, the handle may be readily
rotated between the two preselected positions about axis
24 of the extension 28 against the releasable biasing
action of the spring washer 37 in positioning the exten-
sion portion 28 in either of the desired selected posi-
25 tions of Figures 3A and 3B.
The improved swingable handle of the presentinvention provides automatic preselection of the handle
dispositions with a self-locking feature assuring that
the handle be retained in the desired preselected posi-
30 tion during the bending operation. The complete enclo-
sure of the swivel mechanism provides long, troublefree
extended life. The loading of the swivel by means of the
spring washer provides controlled smooth adjustment. The
swivel structure is extremely simple and economical of
35 construction while yet providing the highly desirable
~30~6~2
functioning discussed above.
The foregoing disclosure of specific embodiments is
illustrative of the broad inventive concepts comprehended
by the invention.
. _ .
