US2749173A

US2749173A - Gripping apparatus for handling elongated objects

Info

Publication number: US2749173A
Application number: US292135A
Authority: US
Inventors: Alden W Peterson
Original assignee: United States Steel Corp
Current assignee: United States Steel Corp
Priority date: 1952-06-06
Filing date: 1952-06-06
Publication date: 1956-06-05
Anticipated expiration: 1973-06-05

Description

June 5, 1956 A. w. PETE-RSON GRIPPING APPARATUS FOR HANDLING EILONGATED OBJECTS Filed June 6, 1952 United States Patent GRIPPING APPARATUS FOR HANDLING ELONGATED OBJECTS Alden W. Peterson, Lorain, Ohio, assignor to United States Steel Corporation, a corporation of New Jersey Application June 6, 1952, Serial No. 292,135

4 Claims. (Cl. 294-113) The present invention relates to apparatus for handling elongated objects and more patricularly to a gripper mechanism especially suitable for facilitating the grasping and lifting of elongated objects.

The apparatus of the present invention is especially suited for handling refractory tuyeres of the type used in Bessemer converters, and is, therefore, described in connection with the handling of such tuyeres while being installed in the bottoms of Bessemer converters. It is to be understood, however, that the invention is not limited to such application.

' The tuyeres used in Bessemer converters are made of refractory material formed in the shape of elongated cyinders having shoulders at one end. The tuyeres which are imbedded in refractory material covering the bottom of the converter extend upwardly when in operating position to conduct air into the converter. Through use, the bottom refractory and the tuyeres of a Bessemer converter burn partly away and must be replaced. The replacement tuyeres are pushed up through the openings in the bottom plate of the converter and are fastened in place from below with bar clamps while brick and refractory mud are filled in around them to repair the bottom. During installation, the replacement tuyeres are pushed up from below through the openings in the converter bottom singly by workmen positioned underneath the converter bottom. As each tuyereis pushed up through its opening, it is grasped by a workman standing above on the bottom plate and raised until the tuyere shoulder abuts the socket edge of the opening. Then the workman above holds the tuyere in position until the workmen below afiix the clamp bar in position.

Prior to my invention, the workman above lifted the tuyere with his hands and then held it in raised position between his legs, using both legs and arms to hold the tuyere steady while it was being fastened below.

In some plants the workmen above used a pair of tongs which were provided with curved jaw faces shaped to grip the tuyere. These tongs were manipulated by pushing the handles toward one another to cause the curved jaw faces to close on the tuyere. The gripping force exerted by this tool was approximately equal to the force exerted by the horizontal arm squeeze at the handles. When using this tool, it was necessary for the workman to simultaneously squeeze on the handles while exerting a lifting force to support the tuyere and to hold the shoulder up against the socket. This was a difiicult task, with arms at chest height, lifting and squeezing, with no appreciable mechanical advantage. The danger of the tuyere getting loose and slipping constituted a considerable safety hazard to the men working below the converter bottom.

It is, accordingly, an object of my invention to provide a pivoted lifting clamp for handling an elongated object which, when fitted around the object, exerts a positive gripping force when lifted.

It is a further object of my invention to provide clamping apparatus which may be used by a workman for lifting and supporting an elongated object in a vertical plane with a minimum of physical exertion.

These and other objects will become more apparent after referring to the following specification and attached drawings, in which:

Figure 1 is a plan of the tool of my invention in position for gripping a tuyere or other elongated object;

Figure 2 is a side elevational view of Figure 1;

Figure 3 is a sectional view taken on the line III-III of Figure 1;

Figure 4 is an enlarged detail side elevational view showing the limit of movement of the pivotal members of my tool in open non-gripping position; and

Figure 5 is a view similar to Figure 4 showing the limit of movement of the pivotal members in closed gripping position.

Referring more particularly to the drawings, reference numeral 2 indicates generally the circular sleeve lift clamp of my invention. The clamp is composed of two tapered or coniform

split ring halves

4 and 6 which are pivotally jointed at their ends. The pivotal connection between the two split ring halves may be achieved by providing a bifurcated member 8 on each end of the ring half 6 and a tongue member 10 at each end of the ring half 4 which is adapted to fit between the bifurcations of the member 8. The bifurcated members 8 and the tongue members It) are each provided with matched openings, not numbered, therethrough which are located a slight distance from the bottom edge of the clamp. When the tongues 10 are fitted into the members 8, the matched holes are in alignment to receive a hinge pin 12 which holds the ring halves in pivotal connection. Each of the hinge pins 12 may be secured by means of a cotter pin 14.

As a result of the coniform construction of the split ring halves, the assembled clamp 2 is similar in shape to a section of a hollow cone with a small diameter opening 16 at the top and a relatively larger diameter opening 18 at the bottom. The hinge pins lie in a common plane slightly above the larger diameter opening 18. The diameter of the top opening 16 is somewhat larger than the outside diameter of the tuyere W to be handled so as to allow easy passage of the tuyere in and out of the clamp.

To assure a non-slipping grip, blades or grips 20 may be welded or otherwise attached to the inner periphery of the assembled clamp coincident with the smaller diameter opening 16.

An inverted L-shaped handle 22 is attached to the outer surface of the mid-section of each of the

ring halves

4 and 6 for pivoting the same and lifting the clamp. Each of the handles 22 has a relatively long portion 24 extending in the direction opposite to the larger diameter opening 18 angularly away therefrom and a short portion 26 extending outwardly substantially normal to the portion 24.

In operation, the workman standing above on the bottom plate being repaired holds the gripper loosely by the handles 22 with the tapered opening aimed to receive the tuyere as it is pushed up through the opening in the plate. When the tuyere has passed a short distance through the clamp, the workman raises the handles 22 causing the gripper jaws to close and the knife-edge blades 2% to bite into the tuyere wall. Then lifting on the handles, the workman pulls the tuyere up until the shoulder thereof is tight in the socket of the opening. He then holds the tuyere in position by exerting a lifting force on the handles 22 until the tuyere is secured from below. After the tuyere is fastened, the workman releases the device by relaxing the lift force, and with an outward breaking movement of the handles, widens the opening between the jaws and lifts the device off.

The hinge pins 12, which connect the

members

8 and 10, are carefully located so as to restrict the pivoting motion of the ring halves in either direction as best shown in Figures 4 and 5. The

members

8 and 10 and pins 12 are positioned so as to restrict the amount the clamp may open so that the bottom of the clamp will not bind on the tuyere as it is being removed therefrom as shown in Figure 4. The pivoting motion of the ring halves in the other direction is also limited as shown in Figure 5 so that the tuyere may easily slide up into the clamp. If the clamp closed up beyond the limits shown in Fig ure 5, it would have to be held rigidly by the handles to receive the tuyere. However, with the pivot point properly located on each side, merely resting the device at the top of the tuyere, while holding it lightly by the handles 22 will cause it to go down over the tuyere, and then stopping the downward movement and exerting a slight lifting force will cause the blades 26 to engage the tuyere surface. Increasing the lifting force on the handles 22 to elevate the tuyere causes the blades hinge pins 12 and the handles 22, through which the vcr tical lifting force is applied, provides a considerable mechanical advantage when the resultant force is transferred to a horizontal grip at the blades. I have found that the gripping power increases in the ratio of about 5 times the lifting force as the tuyere shoulder is pulled up tight in the socket with my device. In other words, if lifting the weight of the tuyere and the gripping tool required a force of pounds upward on each handle, the resultant squeeze of the blades against the tuyere surface would be about 175 pounds, sufficient to prevent slipping and consequent danger.

While one ernbmodiment of my invention has been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. Apparatus for handling an elongated object comprising a pair of first and second tapered split rings, means pivotally connecting said rings together at their ends to form a pivotal sleeve clamp, the taper of said rings forming a relatively greater diameter opening at the lower end of said clamp and a relatively smaller opening at the upper end, said pivotally connecting means including a bracket having an inner wall at each end of said first split ring, said brackets each having a transverse hole therethrough adjacent said larger diameter opening, a tongue projecting angularly from each end of said second split ring and having a lower shoulder thereon, each of said tongues being slidingly fitted into one of said brackets, each of said tongues having a transverse hole therethrough communicating with the holes in said brackets, a pin rotatably fitted through the bracket and tongue at each end of said split rings to thereby pivotally connect the same together, the lower shoulder of each of said tongues cooperating with the inner wall of its respective bracket to prevent the lower end of said clamp from closing on the elongated object as it is moved through the clamp, and a rigid handle attached to the outer surface of each split ring for pivoting the same.

The blades 23 2. Apparatus for handling a cylindrical elongated object comprising a pair of first and second tapered split rings, means pivotally connecting said rings together at their ends to form a pivotal sleeve clamp, the taper of said rings forming a relatively greater diameter opening at the lower end of said clamp and a relatively smaller opening at the upper end, said pivotally connecting means including a bracket having an inner wall at each end of said first split ring, said brackets each having a transverse hole thererhrough adjacent said larger diameter opening, a tongue projecting angularly from each end of said second split ring and having an upper shoulder thereon, each of said tongues being slidingly fitted into one of said brackets, each of said tongues having a transverse hole therethrough communicating with the holes in said brackets, a pin rotatably fitted through the bracket and tongue at each end of said split rings to thereby pivotally connect the same together, the upper shoulder of each of said tongues cooperating with the inner wall of its respective bracket to prevent the upper end of said clamp from closing substantially beyond the diameter of said elongated object so as to facilitate lowering of the clamp onto the elongated object and to prevent excessive indentation of the elongated object by the clamp, and a rigid handle attached to the outer surface of each split ring for pivoting the same.

3. Apparatus for handling a cylindrical elongated object comprising a pair of first and second tapered split rings, means pivotally connecting said rings together at their ends to form a pivotal sleeve clamp, the taper of said rings forming a relatively greater diameter at the lower end of said clamp and a relatively smaller opening at the upper end, said pivotally connecting means including a bracket having an inner wall at each end of said first split ring, said brackets each having a transverse hole therethrough adjacent said larger diameter opening a tongue projecting angularly from each end of said second split ring and having an upper and lower shoulder thereon, each of said tongues being slidingly fitted into one of said brackets, each of said tongues having a transverse hole therethrough communicating with the holes in said brackets, 21 pin rotatably fitted through the bracket and tongue at each end of said split rings to thereby pivotally connect the same together, the upper shoulder of each of said tongues cooperating with the inner wall of its respective bracket to prevent the upper end of said clamp from closing substantially beyond the diameter of said elongated object so as to facilitate lowering of the clamp onto the elongated object and to prexent excessive indentation of the elongated object by the clamp, and the lower shoulder of each of said tongues cooperating with the inner wall of its respective bracket to prevent the lower end of said clamp from closing on the elongated object as it is moved through the clamp, and a rigid handle attached to the outer surface of each split ring for pivoting the same.

4. Apparatus for handling a cylindrical elongated ob ject as defined by claim 3 including gripping means dis posed on the inner periphery of said clamp around the smaller diameter thereof.

References Cited in the file of this patent UNITED STATES PATENTS 148,148 Smith Mar. 3, 1874 189,688 Bogert et al Apr. 17, 1877 1,642,832 Traves Sept. 20, 1927 1,720,500 Watrous July 9, 1929 2,218,845 Kiggins Oct. 22, 1940