Article handling tool

A tool for gripping a remotely located article includes an elongated tubular housing, a tool actuating assembly connected to one end of the housing, and a jaw support member connected to the other end of the housing. A first jaw member having a gripping surface is supported on the jaw support member by a first pair of arms, and a second jaw member having a gripping surface is supported on the jaw support member by a second pair of arms so that the gripping surfaces of the jaw members are disposed in parallel, confronting relation. The two pairs of arms are slidingly and pivotably connected to the jaw support member so that the gripping surfaces of the jaw members may be moved between a first, open position and a second, closed position for gripping an article. When moving between the first and second positions the gripping surfaces move in parallel relation to one another. The tool actuating assembly includes an over-center toggle mechanism so that the jaws are held locked when in the gripping position. An adjustment mechanism for adjusting the distance between the gripping surfaces of the jaw members is provided for accommodating articles of varying size and shape. In an additional embodiment, a plurality of tubular housing sections are provided. A lever arm for operating the tool actuating assembly is formed so that it lies against the elongated tubular housing when the jaw members are moved into the gripping position.

BACKGROUND OF THE INVENTION 
The present invention relates to a tool for gripping remotely located 
articles and more particularly to a gripping tool having spaced parallel 
jaw members which are manually actuated. 
A search of the prior art failed to uncover any prior art references which 
disclose the gripping tool of the present invention. A number of patents 
were uncovered which disclose various article gripping tools. The 
following is a listing of the patents uncovered during the aforementioned 
search: 
______________________________________ 
U.S. Pat. No. Patentee Issue Year 
______________________________________ 
1,455,613 Heppenstall 1923 
2,493,108 Casey 1950 
2,916,323 Van Berkum 1959 
3,312,496 Boutelle et al 
1967 
3,937,512 Baughman 1976 
4,005,897 Smith 1977 
4,039,216 Soos 1977 
4,669,769 Polder 1987 
______________________________________ 
Gripping tools such as those in accordance with the present invention find 
their primary use in the nuclear reactor industry. These tools as designed 
are intended, among other things, for handling radioactive materials under 
water. High level radioactive materials are stored and handled in clear 
water fuel pools in the nuclear industry. Such pools are very deep, some, 
for example, being as deep as 120 feet. The water provides shielding for 
the environment and the personnel handling the nuclear material. At the 
same time, the nuclear materials are cooled and stabilized. 
At times it is necessary to be able to reach into the nuclear reactor, 
using a gripping tool, to retrieve unwanted or dropped items from the 
reactors. Some reactor vessels are 120 feet deep from the work platforms. 
Items to be handled vary in size from small flakes to very heavy objects 
such as nuts and wrenches. In one incident which resulted in a three day 
delay of a reactor start-up, a cold chisel which was being used some 
distance from an open fuel position in a reactor vessel, inadvertently 
dropped into the reactor opening. The cost of retrieving the chisel was 
estimated at over $400,000.00. 
Prior art gripping tools are known in which the jaw faces do not maintain a 
parallel relationship during the gripping operation, such as U.S. Pat. No. 
3,219,376 of the present inventor and U.S. Pat. No. 1,455,613 to 
Heppenstall. For example, in the tool of Heppenstall, the jaws are 
spring-loaded and any parallelism of the jaws is the result of the shape 
of the object being grasped when the jaws are closed. A further prior art 
device is disclosed in U.S. Pat. No. 3,312,496 to Boutelle et al, which 
attempts to maintain the parallelism between the two jaw faces as the jaw 
members are moved between the open and closed positions. However, the 
device of Boutelle et al employs a complicated mechanism, which is not 
suitable for use in the nuclear industry. In the nuclear industry 
simplicity of design is an important factor, since in the handling of 
nuclear or hazardous products all potential aspects of safe operations 
must be considered and the tools must be designed to contain the least 
possible points of failure with a bare minimum of parts which, in use, 
could possibly fall off or otherwise be dislodged. Furthermore, in these 
devices the closure method should offer a feature of instant opening of 
the jaws should a member fail due to breakage or failure. Thus, the 
gripping tools for the aforedescribed application in the nuclear industry 
should be as fail-safe as possible. 
While the current use contemplated for the gripping tool of the invention 
is primarily in the nuclear field, a much broader application of the tool 
is, of course, possible. For example, the gripper in accordance with the 
present invention could be used on robotic equipment. Forest products 
could be handled by the gripping tool of the invention, if the tool were 
made on a much larger scale. Hydraulic and air closing operation of the 
tool is also possible. Grippers for unmanned submarines and outer space 
uses are also possible. The device could also be useful for handling high 
temperature objects, such as in the blacksmithing art or for laboratory 
use. 
SUMMARY AND OBJECTS OF THE INVENTION 
In view of the foregoing limitations and shortcomings of the prior art 
devices, as well as other disadvantages not specifically mentioned above, 
it should be apparent that there still exists a need in the art for a 
gripping tool which maintains parallelism between the jaws in a fail-safe 
manner. It is therefore a primary objective of this invention to fulfill 
that need by providing a tool for gripping a remotely located article 
which maintains the parallelism between the two jaw faces of the tool as 
the jaw faces are moved from an open to a closed position. 
It is another object of this invention to provide such a tool for gripping 
a remotely located article which is readily adjusted. 
It is another object of this invention to provide a tool for gripping a 
remotely located article wherein the tool actuating assembly has an 
over-center toggle mechanism. 
Yet another object of this invention is to provide such a tool which is 
relatively fail-safe in operation. 
Still another object of this invention is to provide a tool which has a 
simplicity of movement, thereby reducing the number of parts of the 
mechanism for safe use in operation of the tool. 
Briefly described, the aforementioned objects are accomplished according to 
the invention by providing an elongated tubular housing defining a 
longitudinal axis of the tool, with a tool actuating assembly connected to 
one end of the housing. Jaw support means are connected to the other end 
of the housing. A first jaw member and a second jaw member are supported 
on the jaw support means and are disposed so that the jaw members are in 
parallel, confronting relation with respect to the gripping surfaces of 
the two jaw members. The jaw support means includes a support member and a 
first and second pair of arms. At least one pair of the arms is slidingly 
and pivotably connected to the support member, with the jaw support means 
connecting the tool activating assembly to the first and second jaw 
members for movement of the first and second jaw members between an open 
and a closed position. The gripping surfaces are moved in parallel 
relation with one another from the open to the closed positions. Further, 
the tool actuating assembly is an over-center toggle mechanism. Finally, 
an adjustment means located proximate to the tool actuating assembly 
allows adjustment of the distance between the first and second jaw members 
in the closed or open positions. 
The foregoing and other objects, advantages and features of the invention 
that will become hereinafter apparent, the nature of the invention may be 
more clearly understood by reference to the following detailed description 
of the invention, the appended claims and to the several views illustrated 
in the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now in detail to the drawings wherein like parts are designated 
by like reference numerals throughout, there is illustrated in FIGS. 1 
through 4 a tool for gripping remotely located articles which is 
designated generally by reference numeral 10. 
Gripping tool 10 comprises a handle 12 which is fixed to one end of an 
elongated tubular housing 14 by means of a threaded connection 13 (FIG. 
4). Elongated tubular housing 14 is connected at the other end to a jaw 
support means or cross piece 18 by means of a threaded connection 19 (FIG. 
4). A connecting shaft or push rod 16 is located within the interior of 
housing 14 and extends coaxially within the housing from a position beyond 
handle 12 to a position just short of the free extremity of jaw support 
means 18. Connecting shaft 16 is threaded at both ends; at one end for 
threaded engagement outwardly of the handle 12 with an adjustment knob 58 
held captive on a rear actuating piston 15 which is slidingly received in 
a bore in handle 12; and at the other end in the area of jaw support means 
18 with a front actuating piston 17 which is slidingly received in tubular 
housing 14. 
Jaw support means 18 is provided with a hollow interior at its forward or 
outermost end. A first pair of generally C-shaped arms 20 are provided 
with one end of arms 20 lying within the hollow interior of jaw support 
means 18. A second pair of generally C-shaped arms 22 are provided with 
one end of each of the arms also lying within the hollow interior of jaw 
support means 18 and extending in a direction which is generally opposed 
to the direction in which the arms 20 extend. Each end of the arms 20 
which lies within the hollow interior of jaw support means 18 is pivotally 
connected with a respective one of the ends of arms 22 and with front 
actuating piston 17 at one of two enlarged portions 21 of front actuating 
piston 17 by means of pins 23. Each of the confronting interior walls of 
the jaw support means 18 is provided with a longitudinally extending 
groove 25 (FIG. 4) to accommodate and guide the ends of pins 23 projecting 
from the front and rear surfaces of arms 20, 22. 
One of the shanks of each of the C-shaped arms 20 is provided with a 
longitudinally extending cam slot 28. Similarly, one of the shanks of each 
of the C-shaped arms 22 is provided with a longitudinally extending cam 
slot 30. Each of the cam slots 28, 30 slidingly cooperates with one of two 
pairs of cam pins 32 which are fixed in jaw support means 18. The pins 32 
extend from the front surface to the rear surface of jaw support means 18 
through holes formed in jaw support means 18. Cam pins 32 are retained in 
jaw support means 18 by suitable retainers, such as conventional retaining 
rings, disposed at the front and rear surfaces of jaw support means 18. 
At their other ends, arms 20 are pivotally connected to a first jaw member 
24 by means of pivot pins 33. Similarly, the other ends of arms 22 are 
pivotally connected to a second jaw member 26 by means of pivot pins 33. 
Pivot pins 33 are retained on jaw support members 24, 26 in a manner 
similar to that in which cam pins 32 are retained on jaw support means 18. 
A plane intersecting the axes of the pivotal connections of arms 20, 20 
with first jaw member 24 by pivot pins 33 is disposed parallel to the 
longitudinal axis A--A of the tool. A plane intersecting the axes of the 
pivotal connection of arms 22, 22 with second jaw member 26 by pivot pins 
33 is also disposed parallel to the longitudinal axis A--A of the tool. 
Each of the jaw members 24, 26 has a gripping surface 27. Jaw members 24 
and 26 are arranged on arms 20, 22, respectively, such that gripping 
surfaces 27 are disposed in parallel, confronting relation with one 
another. In the illustrated embodiment, gripping surfaces 27 are generally 
rectangularly-shaped flat surfaces having a knurled surface finish. It 
will be appreciated, however, that gripping surfaces 27 may be so 
configured as to accommodate a variety of articles to be gripped, such as 
round bars, and the so-configured gripping surfaces may be oriented either 
parallel with or perpendicular to the longitudinal axis A--A of the tool 
10. 
It will be apparent from a further consideration of FIG. 1 that a first 
plane intersects the axes of the pivotal connections of the ends of arms 
20, 20 with enlarged portions 21, 21 of front actuating piston 17 by pivot 
pins 23, and a second plane intersects the axes of the pivotal connection 
of the ends of arms 22, 22 with enlarged portions 21, 21 of front 
actuating piston 17 by pivot pins 23. In the illustrated embodiment, the 
first and second planes coincide with each other and with the longitudinal 
axis A--A of the tool. As previously described, a third plane intersects 
the axes of the pivotal connections of the ends of arms 20, 20 with the 
first jaw member 24 by pivot pins 33, and a fourth plane intersects the 
axes of the pivotal connections of the ends of arms 22, 22 with the second 
jaw member 26 by pivot pins 33. A fifth plane intersects the axes of the 
pivotal connections of arms 20, 20 to jaw support member 18 intermediate 
the ends of arms 20, 20 by means of cam slots 28, 28 guided on cam pins 
32, 32 and a sixth plane intersects the axes of the pivotal connections of 
arms 22, 22 to jaw support member 18 intermediate the ends of arms 22, 22 
by means of cam slots 30, 30 guided on pins 32, 32. In accordance with the 
invention, all of the six planes are parallel to one another, and remain 
parallel to one another during movement of jaw members 24, 26 between the 
open and closed positions. 
At the end of the elongated tubular housing 14 opposite jaw support means 
18, a handle 12 for actuating and gripping the tool 10 is provided. Handle 
12 is provided with a tubular section 34 which is threadedly engaged over 
the end of tubular housing 14 by means of a threaded connection 13 (FIG. 
4) so as to rigidly fix handle 12 to housing 14. Rear actuating piston 15 
is slidingly received in the end of tubular section 34 opposite to 
threaded connection 19. Rear actuating piston 15 is provided with a 
central longitudinal bore having a diameter greater than the diameter of 
connecting shaft 16 so that shaft 16 can freely passes through piston 15 
for assembly of the tool. However, shaft 16 is connected to piston 15 
through the intermediary of an adjustment knob 58 which is held captive on 
piston 15 in a manner to be described hereinafter. Adjustment knob 58 is 
connected to shaft 16 by means of an internal thread 60 which engages the 
threaded end of shaft 16. 
Extending perpendicularly away from tubular section 34 of handle 12 is a 
gripping section 36, which is provided with an opening 38 to accommodate 
the hand of the user of tool 10. A bifurcated projection 40 projects 
perpendicularly away from tubular section 34, disposed to the rear or 
outwardly of gripping section 36. A projection 42 also projects 
perpendicularly away from rear actuating piston 15, toward the rear or 
outward end of piston 15. 
Extending between the bifurcations of projection 40 of handle 12 and 
projection 42 of rear actuating piston 15 is an over-center toggle 
mechanism, generally designated by reference numeral 44. Over-center 
toggle mechanism 44 includes a lever arm 46 and a link 48. Lever arm 46 is 
pivotally connected at the end of a shank of the lever arm to projection 
42 of rear actuating piston 15 by means of a pivot pin 50. The other end 
of this shank of lever arm 46 is pivotally connected to one end of link 48 
by means of a pivot pin 52. The other end of link 48 is pivotally 
connected to projection 40 of handle 12 by means of another pivot pin 54. 
When lever arm 46 and link 48 are placed in the solid line positions 
illustrated in FIG. 1, link 48 and lever arm 46 are so arranged that the 
spacing between pivot pins 54 and 50 is near the maximum spacing. In this 
position, then, piston 15 assumes substantially its maximum rearward 
position, in other words, to the right as illustrated in FIG. 1, with 
respect to handle 12 and elongated tubular housing 14. Also in this 
position, pivot pins 23, connecting arms 20, 20, 22, 22 with front 
actuating piston 17, are positioned at their extreme rearward position, in 
other words to the right as illustrated in FIG. 1. In this position, then, 
arms 20, 20 and 22, 22 are positioned on pivot pins 32 such that the 
distance d between first jaw member 24 and second jaw member 26 is at a 
minimum, so that the jaws are closed for grasping an object therebetween. 
When lever arm 46 and link 48 are in the phantom line position illustrated, 
in FIG. 1, pivot pin 52 connecting link 48 and lever arm 46 is displaced 
downwardly as seen in FIG. 1 or away from the longitudinal axis A--A of 
the tool, and pivot pin 50 is moved to a position closer to pivot pin 54. 
Piston 15 is thus moved to a forward position with respect to handle 12 
and housing 14, or to the left as illustrated in FIG. 1. In this position, 
pivot pins 23 are positioned in their forward position within jaw support 
member 18, in other words to the left in FIG. 1. Arms 20, 20, 22, 22 are 
thus positioned with respect to cam pins 32 such that the distance d 
between first jaw member 24 and second jaw member 26 is at a maximum. In 
this position, then, jaw members 24 and 26 are open and provide sufficient 
clearance such that an article may be positioned therebetween, in 
preparation for gripping the article. 
One important feature of the over-center toggle mechanism 44 is that the 
link and lever arrangement provides a considerable mechanical advantage in 
closing the jaw members of the tool. Another important feature of 
over-center toggle mechanism 44 is due to the movement of pivot pin 52 
just slightly over a center axis of the toggle mechanism drawn between 
pivot pins 54 and 50. Due to this arrangement, when jaw members 24, 26 are 
closed in other words, when lever arm 46 assumes the solid line position 
illustrated in FIG. 1, with lever arm 46 abutting gripping section 36 of 
handle 12, lever arm 46 is locked in this over-center position of toggle 
mechanism 44 and jaw members 24, 26 will positively and forcefully grip 
the remotely located article until lever arm 46 is moved from the locked 
position with the substantial force necessary to shift the over-center 
toggle mechanism to the phantom line position. 
An adjustment means, generally indicated by numeral 56, is provided at the 
rear end of rear actuating piston 15, proximate the tool actuating 
assembly, for adjusting the distance d between first and second jaw 
members 24, 26 so that a variety of sizes of articles may be gripped 
therebetween. Adjustment means 56 includes an adjustment knob 58 which is 
provided with an internal thread 60 for receipt of the threaded end of 
connecting shaft 16. An inwardly projecting lip 62 is formed at the 
forward end of knob 58 and mates with a groove 64 formed on the rear end 
of rear actuating piston 15. By means of lip 62 mating with groove 64, 
adjustment knob 58 is held captive on rear actuating piston 15 and is 
rotatable on rear actuating piston 15. As adjustment knob 58 is rotated on 
rear actuating piston 15 threads 60 engage the threaded end of connecting 
shaft 16 and move the shaft 16 either forwardly or rearwardly within 
elongated housing 14, depending on the direction of rotation of adjustment 
knob 58. As connecting shaft 16 is moved forwardly or rearwardly it 
carries with it front actuating piston 17 and enlarged portions 21, 21 
connected to the rear ends of arms 20, 20 and 22, 22 by pivot pins 23. 
Arms 20, 20, 22, 22 thus slide and pivot within jaw support member 18, 
with slots 28, 28, 30, 30 riding on cam pins 32. Jaw members 24, 26 are 
accordingly brought closer together or are forced further apart, adjusting 
distance d between the jaw members. Adjustment knob 58 is also provided 
with an opening 66 (see FIG. 3) in the side of the adjustment knob 58 in 
the area of lip 62 so that the adjustment knob may be slid over the end of 
rear actuating piston 15 for assembly of the adjustment knob. 
In operation, the tool 10 is first readied for gripping a remotely located 
article by adjusting the distance d between first jaw member 24 and second 
jaw member 26. To adjust the distance jaw members 24, 26 are first closed 
by moving lever arm 46 to the full line position illustrated in FIG. 1. 
Since the articles to be gripped are usually of constant size and shape, 
an article of the same or similar size and shape as the one to be gripped 
is positioned between jaw members 24, 26. Adjustment knob 58 is then 
rotated to adjust the distance d so that the test article firmly fits 
between and is forcefully gripped by jaw members 24 and 26. The test 
article is then released from the jaw members 24, 26 by moving lever arm 
46 to the phantom line position shown in FIG. 1, thereby opening jaw 
members 24, 26. 
With the jaw members 24, 26 in the open position, that is, with lever arm 
46 moved to the phantom line position in FIG. 1, the operator holds the 
tool 10 by handle 12 and positions the tool so that jaw members 24, 26 
surround the remotely located article to be gripped. Gripping the handle 
12 with the operator's fingers received in opening 38, the operator 
squeezes lever arm 46 so that it moves from the phantom line position to 
the full line position shown in FIG. 1. This movement of lever arm 46 
causes pivot pin 52 to be displaced in the upward direction of FIG. 1 or 
toward the longitudinal axis A--A of the tool. The movement of pivot pin 
52 against link 48 pushes pivot pin 50 to the rear, or to the right in 
FIG. 1, and carries rear actuating piston 15 in the same direction. Rear 
actuating piston 15 moving to the rear carries in turn adjustment knob 58, 
connecting shaft 16, front actuating piston 17 having enlarged portions 
21, pivot pins 23 and the ends of arms 20, 20, 22, 22 to which pivot pins 
23 are connected, to the rear, or to the right in FIG. 1. Arms 20, 20 and 
22, 22 thus slide and pivot on jaw support member 18, with cam slots 28 of 
arms 20, 20 and cam slots 30 of arms 22, 22 sliding and pivoting on cam 
pins 32 fixed to jaw support member 18. The sliding and pivoting movement 
of arms 20, 20, 22, 22 brings jaw member 24, which is pivotally connected 
to the ends of arms 20, 20 by pivot pins 33, and jaw member 26, which is 
pivotally connected to the ends of arms 22, 22 by pivot pins 33, together, 
so that gripping surfaces 27 firmly grasp the article to be gripped. Due 
to the arrangement of cam slots 28, 30 riding on cam pins 32 and the 
alignment of pivot pins 33 on jaw members 24, 26, respectively, jaw 
surfaces 27 move in a parallel relation to one another between the open 
and closed positions of jaw members 24, 26. The entire tool 10 is then 
lifted and swung by the operator to a suitable location, with the article 
firmly gripped between jaw members 24, 26. Lever arm 46 is then moved by 
the operator to the phantom line position shown in FIG. 1, opening jaw 
members 24, 26 and releasing the article. 
Referring now to FIGS. 5 and 6, an alternate embodiment of the invention is 
illustrated the tool of the alternate embodiment being designated by the 
reference numeral 10'. In the illustrated embodiment, the elongated 
tubular housing is formed by a front elongated tubular housing 14a' and a 
rear elongated tubular housing 14b'. A female coupling sleeve 70' 
threadingly engages the rear end of front housing 14a', and is firmly 
fixed to housing 14a'. Female sleeve 70' is provided with a groove 72' at 
the rear end thereof. A male coupling sleeve 74' threadingly engages the 
front end of rear housing 14b' and is firmly fixed thereto. A tongue 76' 
is formed on the front of male coupling sleeve 74' and mates with groove 
72 formed on the rear of female coupling sleeve 70'. The outside of the 
front end of male coupling sleeve 74' is threaded for engagement with a 
knurled coupling nut 78'. To assemble the elongated tubular housing of 
tool 10' of the illustrated embodiment, front housing 14a' and rear 
housing 14b' are brought into abutting engagement with one another, with, 
tongue 76' mating in groove 72'. Knurled coupling nut 78' is then threaded 
onto the front end of male coupling sleeve 74' and tightened so that a 
firm connection is achieved between front housing 14a' and rear housing 
14b'. According to this embodiment, the elongated tubular housing may be 
made from a plurality of tubular housing segments, thereby facilitating 
the manufacture of the tool 10' and assembly of the tool into any desired 
length. 
An additional difference between the embodiment of FIGS. 5 and 6 and that 
of FIGS. 1 through 4, lies in the use of a tool actuating sleeve 80' which 
is not provided with an extending gripping section 36, as is the 
embodiment of FIGS. 1 through 4. Further, lever arm 46' is formed so that 
an axis drawn through pivot pins 52', 50' passing through shank 46a' is 
substantially parallel with the longitudinal axis of the arm portion 46b' 
of lever arm 46'. According to this arrangement, when lever arm 46' is 
moved into the position to close jaws 24', 26', arm portion 46b' of lever 
arm 46' lies against the outside surface of rear housing 14b'. When the 
operator manipulates the tool 10' with an article gripped between jaws 
24', 26', arm section 46b' of lever arm 46' together with rear housing 
14b' is gripped by one hand of the operator. 
In the embodiment of FIGS. 5 and 6, the operation and structure of the 
jaws, including jaw members 24', 26, arms 20', 20', 22', 22', jaw support 
member 18, as well as over-center toggle mechanism 44' and adjustment 
means 56' including adjustment knob 58' are all the same as that of the 
embodiment illustrated at FIGS. 1 through 4. Accordingly, further 
description of those features of the embodiment of FIGS. 5 and 6 is 
unnecessary. 
Although only preferred embodiments are specifically illustrated and 
described herein, it will be appreciated that many modifications and 
variations of the present invention are possible in light of the above 
teachings and within the purview of the appended claims without departing 
from the spirit and intended scope of the invention.