US2398403A - Junction box for rope thimble - Google Patents

Description

April 16, 1946.

E. H. BORGELT 2,398,403

JUNCTION BOX FOR ROPE THIMBLE Filed Sept. 20 1944 2 Sheets-Sheet 1 INVENTOR. v v v 12/[19/9/80/96427 ATTORNEY April 1946- I BORGELT 2,398,403

JUNCTION BOX FOR ROPE THIMBLE Filed Sept. 20 1944 2 Sheet-Sheet 2 v 0 O I INVBVTOR. 17/141296! fl/96:17

ATTORNEY Patented Apr. 16, 1946 JUNCTION BOX FOR ROPE THIMBLE Elmer H. Borgelt, Dayton, Ohio; assignor to the Government of the United States of America, as represented by the Secretary of War Application September 20, 1944, Serial No. 554.932

(Granted undr the act of March 3, 1883, as amended April 30, 1928; 3-70 0. G. 757) 4 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

The invention to be hereinafter described relates to a thimble block junction box for ropes.

In towing, especially airplane towing, there are many difiiculties encountered in the electrical connections between the conductors carried by the rope and the object to which the conductor is connected at one or the other end. Some of these are due to the difference in elongation between the conductor and the tow rope carrying the conductor, which is well understood. Various provisions have been made to compensate this difference, with considerable success. Ther still remain evident diificulties at and near the thimbles and adjacent connections. In use, especially in towing use with airplanes, the thimble and all parts immediately carried thereby or closely connected thereto receive very severe punishment. The tow rope is regularly dropped as the tow is ended and falls full weight from a considerable height.

Oneof the most serioustroubles is due to excessiv strain on the conductor in pulling out the connection when the tow rope is disconnected. Either the usual plug-and-socket coupling is damaged or the conductor is torn from the coupling or the conductor is otherwise damaged. One protective arrangement against this is to provide. slack in the conductor adjacent the thimble, with a. short. chain or the like from the thimble to the respective plug-and-socket memher, the chain being of such length as. to pull the. member before strain falls on the conductor. That still leaves the plug-and-socket member swinging on the free end of the conductor. When damaged by the fall, as is very frequent, it. must be removed and a new one connected. This may not be serious at a near base but, even there it requires appreciable time.

The present invention eliminates or greatly minimizes th above and other objections and provides. a simple efiicient, compact and durable junction box carried by the thimble and providing speedy and eificient connections for renewing the damaged plug-and-socket-member.

In. order to more clearly disclose the construction, operation and use of the invention reference. should be had to the accompanying drawings forming. part of the present application.

lik reference characters designate the same parts in the different views.

In thedrawings:

Fig. 1 is aside elevation of a tow connection as at present used;

Fig. 2 is a like view showing the invention applied;

Fig. 3 is a view similar to Fig. 2, with the remote box wall removed;

Fig.4 isatop plan view of Fig. 2;

'Fig. 5 is a cross section on line 5-'.i of Fig 2; and

Fig. 6 is a plan view of the inside of one of the box walls, removed.

The present type is shown, as in Fig. 1, purely for purposes of comparison and needs no further description.

As shown in the drawings, the invention has been designed, proportioned and constructed to be received and fit completely within the loop of the roughly pear-shaped or U-shaped looped thimble of the usual tow rope. The housing, casing, chamber or box so constructed, arranged or disposed, together with the thimble provides good reliable protection for the contacts or junction elements or connections to the conductor carried by the tow rope.

Preferably, two metal blocks l of complementary construction are used. They are,

roughly, pear-shaped or approximately eggshaped in outline. They are of approximately the same minimum peripheral measurementas the minimum peripheral measurement of the inner wall or loop of the thimble 2. Each block is recessed as at 3 to provide one part or section of a chamber, box or the like to contain the desired electrical connections; Each block I is also provided with a peripheral flange 4 of concave cross section adapted, when in operative position, to fit snugly on or nest with the cooperating wall of thimble 2. In the construction shown, the two assembled flanges 4 approximately span, bridge, seat or embrace the ad- Jacent cooperating half of thimble 2. The blocks I are positively and efliciently secured in operative position by connecting rods 5 passed through one block and threaded into the other.

Any other suitable connecting means may be used. The blocks, assembled and drawn together in this way, are securely clamped in place within the loop of the thimble. The edges of the thimble form a good continuous and eflicient protection to the box. The assembled. blocks, it will be noticed, do not. extend" or project ap- Throuahout the several figures-. 0: the l0 preciably beyond the: thimble in. any direction In effect, the structure is a rigid, shallow box or chamber having the same outline as the inner wall of the thimble 2 and having a maximum thickness approximately equal to that of the thimble tube providing the necessary or desired chamber or box, room or space, amply protected against all probable shock or abuse. Incidentally, this box uses otherwise waste space. An important consideration is that while, itself, being braced and supported by the thimble, it also very strongly braces that same thimble.

At the large end each block is provided with a notch 6, the notch of one block aligning with that of the other to freely receive the usual link, eye or the like by which the tow rope end is regularly connected to the respective plane. The opposite end of each block is provided with an axially disposed semi-cylindrical or concave throat groove I leading outwardly from recess 3. These two grooves, in operative position, align to provide a cylindrical throat outlet.

It should be noted that, in assembled position, the throat groove I is in approximate alignment with and continuation of the longitudinal axis or center of the adjacent section of the tow rope leading to the thimble.

Usually, the conductor cable carried by the tow rope comprises three conductors. While that is usual, it is not a definite limitation, as is well understood. Because such is the usual arrangement, three conductors are shown in this case.

Within the box, on the wall of one recess, are provided three binding posts 8, one for each of tie usual three conductors of the tow rope.

Adjacent binding posts 8 are a second series of three binding posts 9, for a purpose to be later disclosed.

In operation, the three conductors are led in through the throat I and, each provided with the usual terminal, connected in usual manner to one of the binding posts 6. Ample slack is provided to compensate for the predetermined, calculated, elongation of the adjacent section of the particular type of tow rope. A closely coiled strong spring It provides an adequate guide and ample protection for the conductors from the tow rope, through throat 1, into recesses fiend to a point close to the binding posts 8. It provides a complete shield and protection or armor between the conductors and the throat I. As shown, it extends outwardly beyond the throat I to the adjacent splice end. At this point, the spring is securely anchored, or connected to the tow rope by a loop I! which is simply branched off from and extended around and about the two adjacent branches of the loop. So, as the rope elongates, under tension of a tow, for instance, the spring clongates correspondingly and the provided slacl: in the conductor pays out. And, as the tension and elongation decrease the spring contracts and the slack returns. Thus, the spring It} is-an armored protection and guide for the conductors.

The above provides a solid, substantial, eificient and compact complete unit with all electrical connections amply protected against all probable shock or damage.

In order to continue the conductor connections from the junction box to the usual plug-andsocket-member, a short conductor section I2 having the usual three conductors, is provided. One end of this is connected in usual and well known manner to the plug-and-socket member while.

a suitable bore or opening through one of the blocks I, adjacent the posts 9, the usual slack being allowed and a short wire rope I4 being provided between block I and the plug-and-socket member to prevent injury to section I2 in disconnecting.

As the tow rope is dropped or as it is dragged, as is very frequently the case, there is a tendency to scrape or scoop sand and dirt through throat I to the interior where it may cause trouble. To prevent or, at least, minimize that difllculty, a guard l5 in the form of a washer, ring or the like of rubber or other suitable ma terial is used.

These short sections I2, a foot or so long, with plug or socket may be easily and quickly attached and detached with efficient connections and in extremely little time. This may be done anywhere with equal ease. If the plug or socket member or the section I2 becomes damaged it is only necessary to loosen the screws of the binder posts 9, pull out the terminals of a new section I2 and tighten the same screws. Of course, the new wire rope I4 would also be connected.

With this arrangement the two rope is a complete and entire unit in itself, while section I2 is another complete unit cooperating with but separable from the tow rope. The two, however, in assembled relation, are essential for communication between a tow plane and its tow or in any analogous relation where communication is involved.

It is thought that the construction, operation and use of the invention will be clear from the preceding detailed description.

Many changes may be made in the construction, arrangement and disposition of the various parts of the invention within the scope of the claims without departing from the field of the invention and it is meant to include all such within this application wherein only one preferred form has been shown purely by way of illustration and with no thought or intention to, in any degree, limit the invention thereby.

Having thus disclosed my invention, what I claim and desire to protect by Letters Patent is:

1. In combination, a looped thimble, a junction box within the loop of said thimble, supported by said thimble, bracing said thimble outwardly from within and braced inwardly by said thimble, means within said box for connecting conductors thereto, conductors leading into said box to said connecting means, an extensible armor surrounding said conductors and means securing said box in operative position.

2. In combination, a looped thimble, a junction box within the loop of said thimble and disposed approximately within the plane of said thimble, said junction box comprising a pair of chambered complementary blocks having an outside dimension substantially that of the corresponding inside dimension of said loop and provided with clamping flanges embracing the corresponding thimble walls, when in assembled relation, and means for drawing said plates into operative clamping and outwardly thimble bracing position with the box shielded by said thimble loop.

3. In combination, a looped thimble, a junction box within the loop of said thimble, supported by said thimble, bracing said thimble outwardly from within and shielded by said looped thimble, said junction box comprising a pair of chambered complementary blocks having an outside dimension substantially that of the corresponding inside dimension of said loop and provided with clam'p said thimble, bracing said thimble outwardly from within and shielded by said looped thimble, said junction box comprising a pair of cooperating plates one having a junction box cavity, said plates having outside dimensions substantially corresponding to the cooperating inside dimensions of said loop and provided with clamping flanges embracing the corresponding thimble walls, when in assembled relation, and means for drawing said plates into operative clamping position.

ELMER H. BORGELT.

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