Remote bending apparatus

A remotely positionable bending apparatus includes a support platform with a mandrel mounted to a front surface thereof and a bending arm pivotally connected between the mandrel and support platform. The outer end of the bending arm rotates around the upper end of the mandrel to bend a rod into a generally inverted U-shape. A clamping apparatus is operably mounted on the platform adjacent the mandrel and includes an actuator which is operated by movement of the bending arm to clamp and release a detector rod in a retained position against the mandrel. Preferably, the actuator includes a shaft which is placed under a biasing force to urge the shaft into a clamped position, with a pivotable lever connected thereto actuatable to overcome the biasing force and release a detector rod from the clamped position. The actuator lever is located in the pivotal path of the bending arm, such that movement of the bending arm to a retracted position disengages the clamping apparatus from the detector rod.

TECHNICAL FIELD 
The present invention relates generally to an apparatus for bending metal 
rods and bars, and more particularly to an improved bending apparatus with 
a single cylinder for actuating a holding clamp and a bending arm on a 
remote housing. 
BACKGROUND OF THE INVENTION 
Nuclear detectors are uranium fission chambers housed within stainless 
steel pipe, and are utilized in nuclear reactors. Typically, such 
detectors are formed of 3/4 inch pipe of approximately 40 feet in length. 
Because the detectors are highly radioactive, they are maintained under 
water to shield radiation. 
In the prior art, detectors were conventionally cut in half and stored 
randomly under water. Because this resulted in handling, storage and 
accountability concerns, various tools were devised to bend the detectors 
into an inverted U-shape such that the detectors may be easily supported 
at the bend and quickly and easily transferred to storage under water. 
While bending tools are known in the prior art, they suffer several 
drawbacks. First, conventional bending tools utilize one hydraulic 
cylinder to clamp the detector into position, and a separate hydraulic 
cylinder to bend the detector in half. The use of two separate cylinders 
to accomplish these two tasks requires a large number of hoses, controls, 
and related accessories, thereby requiring a high degree of maintenance. 
In addition, with independently controlled cylinders, it is possible that 
one cylinder can fail while the other cylinder continues to be operable. 
Thus, it is possible that a detector may not be adequately clamped during 
the bending process, producing a very hazardous condition. 
Another problem with prior art bending tools is in their use of a hydraulic 
cylinder to power the bending arm, and a separate pneumatic cylinder to 
clamp the detector into position. The use of a separate hydraulic cylinder 
requires a separate pump, reservoir, and controls for operation in 
addition to the air compressor necessary to provide pressure to the 
pneumatic cylinder. 
SUMMARY OF THE INVENTION 
It is therefore a general object of the present invention to provide an 
improved remote bending apparatus for bending spent nuclear detectors and 
the like. 
Another object of the present invention is to provide a remote bending 
apparatus which utilizes a single cylinder to operate both a holding clamp 
and the bending arm. 
Still another object is to provide a remote bending apparatus which does 
not require the additional controls and accessory items of a hydraulic 
cylinder driven system. 
Another object of the present invention is to provide a remote bending 
apparatus which is simple to construct, maintain, and operate. 
These and other objects will be apparent to those skilled in the art. 
The remotely positionable bending apparatus of the present invention 
includes a support platform with a mandrel mounted to a front surface 
thereof and a bending arm pivotally connected between the mandrel and 
support platform. The outer end of the bending arm rotates around the 
upper end of the mandrel to bend a rod into a generally inverted U-shape. 
A clamping apparatus is operably mounted on the platform adjacent to the 
mandrel and includes an actuator which is operated by movement of the 
bending arm to clamp and release a detector rod in a retained position 
against the mandrel. Preferably, the actuator includes a shaft which is 
placed under a biasing force to urge the shaft into a clamped position, 
with a pivotable lever connected thereto actuatable to overcome the 
biasing force and release a detector rod from the clamped position. The 
actuator lever is located in the pivotal path of the bending arm, such 
that movement of the bending arm to a retracted position disengages the 
clamping apparatus from the detector rod.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings, in which similar or corresponding parts are 
identified with the same reference numeral, and more particularly to FIG. 
1, the remote bending apparatus of the present invention is designed 
generally at 10 and is shown mounted on a movable platform 12 which may be 
moved into position to retain and bend a detector. 
Platform 12 includes a vertical support plate 14 with the bending apparatus 
10 mounted on the front surface thereof. A pneumatic cylinder 16 is 
mounted on the rearward surface of plate 14, and has a pair of air lines 
18 extending therefrom which supply power to cylinder 16. 
Bending apparatus 10 includes a mandrel 20 mounted to the forward surface 
of plate 14 and includes an upper bending surface 22, a first vertical 
side wall 24, and opposing generally vertical side wall 26 and a forward 
surface 28. The upper end of mandrel 20 is spaced away from plate 14 to 
permit rotational movement of a bending arm 30 between the mandrel and 
plate 14. A clamping apparatus 32 is mounted to plate 14 adjacent the 
first mandrel side wall 24, and serves to clamp a detector in place during 
the bending operation. 
Mandrel 20 provides a stationary support about which a detector rod is 
bent. Bending surface 22 includes a groove 34 with a radius approximately 
the same as a detector rod 36 (shown in FIGS. 2-5) to be bent, and with a 
longitudinal axis which is generally semi-circular and extends from first 
side wall 24 to second side wall 26. 
An actuator shaft 38 extends through plate 14 to interconnect a rack and 
pinion rotary actuator (not shown) driven by cylinder 16, with bending arm 
30. Actuator shaft 38 extends through bearing arm 30 and into an aperture 
through mandrel 22. As shown in FIGS. 2 and 3, actuator shaft 38 is 
located centrally between side walls 24 and 26 of mandrel 20, and forms 
the center of the radius of the longitudinal axis of groove 34. One end of 
bending arm 30 is affixed to actuator shaft 38 for rotational movement 
therewith. While the opposite end projects radially from actuator shaft 
38. 
A roller 40 is rotatably mounted on the projecting end of bending arm 30 
and has an annular groove 42 with the same radius as the detector rod 36 
around the circumference thereof. As shown in FIGS. 2 and 3, groove 42 in 
roller 40 ensures positive engagement and smooth bending of detector rod 
36 as bending arm 30 is rotated on actuator shaft 38. As shown in FIGS. 2 
and 3, bending arm 30 is rotatable between an initial release position, 
shown in FIG. 2, through approximately 210.degree. of rotation to a fully 
engaged position, shown in broken lines in FIG. 3, the path of the bending 
arm shown by arrow 44. 
Referring now to FIGS. 2 and 3, clamping apparatus 32 includes a shaft 46 
slidably journaled through apertures 48a and 50a in forward and rearward 
walls 48 and is 50 of a shaft support bracket 52. The forward end of shaft 
46 has a clamping block 54 affixed thereto with a vertically oriented 
V-shaped groove 56 formed in the forward surface thereof (as shown in FIG. 
4) which will engage a portion of the circumference of detector rod 36 
when shaft 46 is actuated to a clamping position (shown in FIGS. 3 and 4). 
As best shown in FIG. 4, clamping block 54 will apply force against rod 36 
to retain the rod in position against first side wall 24 of mandrel 20, so 
as to firmly retain rod 36 in position. 
Shaft 46 and clamping block 54 are actuated to the forward clamping 
position by the biasing force of coil spring 58, which is operably mounted 
on shaft 46 between clamping block 54 and rearward wall 50 of support 
bracket 52. Coil spring 58 is designed to provide a predetermined clamping 
force on rod 36, which may be overcome so as to release rod 36 by 
actuation of a release lever 60. 
Release lever 60 is generally L-shaped, with a long leg 62 and a short leg 
64, and is pivotally mounted on a pin 66 at the juncture of legs 62 and 
64. A pin 68 affixed perpendicularly to the rearward end of shaft 46 
projects through a slot 70 formed in short leg 64 of lever 60, such that 
pivotal movement of lever 60 on pivot pin 66 will extend or retract shaft 
46 in bracket 52. 
As shown in FIGS. 2 and 3, the projecting forward end of the long leg 62 of 
release lever 60 extends into the path of movement of bending arm 30 such 
that movement of bending arm 30 to the release position shown in FIG. 2 
will pivot lever 60 and retract shaft 46 and clamping block 54 away from 
detector rod 36 to permit removal of rod 36 from mandrel 20. 
As shown in FIGS. 1 and 4, a pair of wedge-shaped guide members 72 and 74 
are mounted on the forward surface 28 of mandrel 20 and a forward surface 
of the forward wall 48 of support bracket 52, respectively. Guide members 
72 and 74 include a sloped surface 72a and 74a, respectively, oriented to 
direct a detector rod 36 towards the opening between mandrel side wall 24 
and support bracket forward wall 48. 
Referring once again to FIG. 1, platform 12 is preferably supported by a 
cable to hang vertically from a hoist (not shown), so as to permit 
movement of support platform 12 in a position remote from the hoist. 
Cylinder 16 is provided with air pressure through air lines 18 which are 
connected to a conventional air compressor available on the hoist's 
operating platform. Pneumatic rotary actuator 16 is a dual action cylinder 
preferably operable on air pressure of approximately 100 pounds, to rotate 
bending arm 30 in both directions about actuator shaft 38. 
As discussed above, the bending apparatus of the present invention is 
preferably utilized in the environment of a nuclear reactor, wherein 
detector rods are handled under water. In operation, a detector rod is 
initially raised out of a reactor utilizing existing conventional handling 
tools. The detector rod is maintained under water at all times. Platform 
12 is then lowered under water to a position wherein bending apparatus 10 
is located generally at the midpoint of the vertically oriented detector 
rod to be bent. The detector rod 36 (as shown in FIG. 2) is then moved 
towards bending apparatus 10 and guided into the position shown in FIG. 2 
by guide members 72 and 74 (shown in FIGS. 1 and 4). 
Once detector rod 36 is appropriately positioned, as shown in FIG. 2, 
bending arm 30 is activated to raise from the release position shown in 
FIG. 2 to an initial clamped position shown in FIG. 3. Movement of bending 
arm upwardly releases lever 60 so as to permit coil spring 58 to move 
clamping block 54 into engagement with detector rod 36, as shown in FIGS. 
3 and 4. Thus, detector rod 36 is securely clamped in position by the time 
bending arm 30 reaches the initial engagement position shown in solid 
lines in FIG. 3. 
Once the detector handling tool is removed from detector rod 36, bending 
arm 30 is actuated so as to move from the initial engagement position A to 
the fully engaged position B, shown in FIG. 3, with the upper end 36a in 
abutting contact with side wall 26 of mandrel 20. It should be noted that 
side wall 26 includes upper and lower portions 26a and 26b, as shown in 
FIG. 2, with upper portion 26a generally parallel to side wall 24, and 
lower portion 26b angled at approximately 3.degree. beyond the vertical, 
shown by angle 76 in FIG. 2. As shown in FIG. 5, it is necessary to bend 
detector rod 36 more than 180.degree. as shown by the broken lines, 
because the resiliency of the metal material of rod 36 will cause upper 
end 36a to return slightly outwardly when the bending arm is released from 
the fully engaged position B (shown in FIG. 3). Thus, in order to obtain a 
generally inverted U-shape, with rod ends 36a and 36b parallel, rod end 
36a must be initially bent to a position angled slightly towards rod end 
36b, prior to release of the rod. 
Upon completion of the bend, platform 12 is moved to a predetermined 
storage location and bending arm 30 is retracted from fully engaged 
position B (see FIG. 3), past initial contact position A, to the release 
position C shown in FIG. 2. In release position C, roller 40 engages 
release lever 60 to retract clamping block 54 and thereby permit removal 
of detector rod 36. 
A vertical slot 78 formed in the upper end of mandrel 20 and extending 
downwardly into upper bending surface 22 and groove 34 permits a hook to 
be inserted under the bent portion 36c of detector rod 36, as shown in 
FIG. 3, to lift rod 36 off of mandrel 20 and place detector rod 36 in a 
designated storage position. 
Whereas the invention has been shown and described in connection with the 
preferred embodiment thereof, it will be understood that many 
modifications, substitutions and additions may be made which are within 
the intended broad scope of the appended claims.