US 3530679 A
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Sept. 29, 1970 J. KRINGS TENSIONING DEVICE FOR THE SHEETING OF MACHI DUG SERVICE TRENCHES Filed Jan. 23, 1969 26 g FL unfing ig U lnvenlor JOSEFM mamas WW1, MAC
United States Patent Ofice Patented Sept. 29, 1970 3,530,679 TENSIONING DEVICE FOR THE SHEETING OF MACHINE DUG SERVICE TRENCHES Josef Krings, 23 Hans-Bockler Str., 6138 Oberbruch, Germany Filed Jan. 23, 1969, Ser. No. 793,409 Claims priority, application Germany, Jan. 24, 1968, 1,708,539 Int. Cl. E02d /00 US. Cl. 61-46 5 Claims ABSTRACT OF THE DISCLOSURE This disclosure relates to shoring which includes 0pposed sheeting having associated therewith hollow posts. Tensioning devices which are longitudinally adjustable extend between the posts and have at the opposite ends thereof housings. The tensioning devices are connected to the posts for adjustment along the posts in interlocked engagement therewith and for each of releasal by generally dumbbell shaped connectors. The tensioning devices may be further extended by the addition of extension elements at the ends thereof, which extension elements may also be axially extensible.
The invention concerns a tensioning device for the sheeting of machine dug service trenches or similar things by means of sheeting plates and of supports arranged thereon, for the reception of the shoes horizontally supportable against the sheeting plates and of tensioning elements adjustable longitudinally by means of a spindle drive.
A known tensioning device consists of sections of pipe which can be connected with one another and of which the pipe sections which happen to be on the outside are developed as a nut for the reception of a threaded spindle whose outside edge carries a block and which are held in posts having a U-profile, which in their turn have been attached firmly to the sheeting plates. Each block is connected firmly with the assigned post by means of bolts.
The known device, which has proven itself quite well, shows however some deficiencies insofar as, on the one hand, the position of a tensioning element was impaired during the pulling of a sheeting plate and at the same time the opposite sheeting plate was also moved out of its position. This led to changes in the profile of the construction trench. Furthermore, it turned out that the freelying threaded spindles of the tensioning elements became clogged considerably with dirt and stuck frequently.
Therefore, the present invention is based on the task of creating a tensioning device which will avoid the above mentioned deficiencies, which, on the one hand, will be insensitive to weather and dirt to a large extent, will not require any screw fastening connections and, on the other hand, will be independent of the movements of a sheeting plate.
The invention resides in the fact that the abutments are developed in the form of steel posts with a slit box profile and that the shoes of the tensioning elements are capable of guiding in a positively locking manner along the entire length of the posts. In this type of development, the tensioning elements can serve both as tensioning members and as pressure members.
Advantageously, provisions have been made that the steel posts can be detachably connected with the sheeting plates. However, the steel posts do not necessarily have to be integrally connected with the sheeting plates. As a result of this, one will accomplish savings in the fabrication of the sheeting plates.
According to a further development of the invention, provision has been made that each tensioning member consists of two spindles with oppositely oriented thread parts facing each other, a pipe telescoped over the spindles with a nut element arranged in the middle with oppositely directed threaded sections, and pressure housings, arranged at the ends of the spindles and with a larger crosssection than-the pipe, also of a shoe which is formed similarly to a dumbbell of two disks or blocks connected axially by way of a pressure bar, one of which blocks can be received in the pressure housing and the other block can be received in a positively locking manner in the steel post.
In the case of this development, the thread part of the tensioning elements is completely protected against dirt. Beyond that, this results in a simple possibility for the extension of the tensioning elements. According to a further characteristic of the invention, extension elements have been provided for the extension of the tensioning elements, which consist of a block that can be inserted into a pressure housing and of a further pressure housing for the reception of the shoe, which further pressure housing is connected with the associated block either rigidly or by means of another threaded connection.
With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claimed subject matter, and the several views illustrated in the accompanying drawing.
In the drawing:
FIG. 1 is a side view with parts in longitudinal section according to the line I-I of FIG. 2 of the tensioning device according to the invention.
FIG. 2 is a top view with parts in longitudinal section following the line II--II of FIG. 1.
FIG. 3 is a top view on an enlarged scale of an extension element. a
In FIGS. 1 and 2 there is shown the tensioning device 1 according to the invention in connection with the sheeting plates 2 and steel posts 3.
The tensioning device 1, as the drawing shows, consists of tensioning elements 4 each of which consists of two spindles 5, 6 with oppositely directed thread parts 7, 8 of a pipe 9 telescoped over the spindles 5, 6 having thread sections 10, 11 which are oppositely directed and arranged in the middle of the pipe, and of pressure housings 12 arranged at the ends of the spindles 5, 6.
Effectively, these pressure housings 12 will have a larger cross-section than the pipe 5 and each has a box-shaped profile which is open on top. Each pressure housing is adapted to receive a shoe 13 which consists, similar to a dumbbell, of two blocks 15, 16 or disks which are rigidly connected with one another by way of a short pressure bar 14 (FIG. 3) and at an axial distance from one another. Every block 16 is introduced into a respective pressure housing 12 through a lateral opening 17 therein and is thus protected against any dirt which may drop down. The block 15 is guided in positively locking engagement in a steel post 3, which, viewed in crosssection, has a slit box profile.
The steel post 3 can stand by itself alone or it can be connected with the sheeting plate 2 either as an integral part thereof or detachably connected thereto. For a better guidance and movement of the shoe 13 in the steel post 3, lateral supports 18 have been provided on each pressure housing 12, the lateral supports carrying guide rolls 19 running along the outside surfaces of the steel post 3.
Usually at least two tensioning elements 4 are required for the tensioning of the sheeting plates 2. The tensioning elements 4 can be connected with one another by means of braces 20, as shown in FIG. 1, to form a tensioning frame. Advantageously, the braces 20 will be releasably attached to the pressure housings 12. This design, moreover, oifers the advantage that the tensioning elements 4 can be pulled out of the service trench as a unit.
The tensioning elements 4 can be manufactured in a uniform length. Within a limited range, the length of the tensioning elements 4 can be varied by twisting pipe 9 and through a corresponding separating movement of the spindle 5, 6.
For a further extension of the tensioning element 4, additional extension elements 21 have been provided (FIG. 3). In the case of the known tensioning elements, such extension elements consisted of flanged pieces of pipe, which were attached to the body of the pipe of the tensioning element by means of screws. However, in practice, the fact that the screws required for this purpose rusted into it or were lost, turned out again and again as being rather disadvantageous.
The extension element 21 according to the invention, as is shown in FIG. 3, consists, as compared to former constructions, of a block 22 which has the same dimensions as the block 16 of the shoe 13, of a pressure housing 23 which is similar to the pressure housing 12, and of an intermediate connection 24, which can be formed either as a rigid bolt (as shown) or else as a pipe or as a further tensioning element with adjustable spindles.
The extension element 21 thus merely needs to be inserted with its block 22 into the pressure housing 12 of the tensioning element 4 in order to extend said element. It is also possible to connect several extension elements 21 in the same manner with one another. Possibly they can also be secured by bolts or other locking elements which can be attached in a suitable manner.
For the extension of the tensioning element, one will under no circumstances use any screws, rather it is a matter of a plug connection. Then the shoe 13 can be inserted in a known manner into the pressure housing 23.
In operation, two tensioning elements 4 are interlocked with the steel posts 3 either seated against the sheeting plates 2 or forming a part of these plates, and then are fixed at the required height, for example, by means of holding bolts 25. Subsequently the pipe 9, which has been provided with extension members 26, will be twisted until the tensioning elements 4 exert the required pressure tension on the sheeting plates 2. If in the course of further work a sheeting plate will be twisted, then the tensioning elements 4 may remain in the horizontal position assumed by them previously, because the steel posts 3 can be moved relatively thereto. The tensioning elements 4 can be used both as pressure and as tensioning elements, because all parts engage with one another in a positively locking manner.
It will be particularly effective to attach three or more tensioning elements 4 one above the other to the same steel posts 3. Thus, one will have the opportunity to loosen one tensioning element 4 at a time and to shift it perpendicularly, while the other tensioning elements 4 continue to hold the sheeting plates 2 firmly.
Although only preferred embodiments of the tensioning device have been specifically illustrated and described herein, it is to be understood that minor variations may be made therein without departing from the spirit of the invention.
1. A tensioning device for use in combination with opposed sheeting plates to form shoring and wherein said sheeting plates have associated therewith abutments in the form of posts, said tensioning device extending between a pair of said abutments and including a threaded drive for adjusting the length thereof and a pair of terminal shoes, each of said abutments being of a split box section and having positioned therein one of said shoes in interlocking engagement and for guided sliding movement therein, the threaded drive of each tensioning element including two spindles having threaded parts which are oppositely directed and face each other, a pipe telescoped over said spindles and having a nut part arranged in the middle thereof with oppositely directed threaded sections, and pressure housings arranged at the ends of the spindles and having a larger cross-section than the pipe, and each shoe having a configuration similar to that of a dumbbell and including two blocks connected by a pressure bar, one block of each shoe being positioned within one of said pressure housings and the other block of each shoe being releasably positioned in a positively locking manner in an associated one of said posts.
2. Tensioning device according to claim 1 wherein extension elements have been provided for the extension of the tensioning elements, each extension element including a block insertable laterally into one of the pressure housings and a further pressure housing for the reception of one of said shoes, said further pressure housing being connected with said extension element block.
3. Tensioning device according to claim 2 together with supports on said pressure housing carrying guide rollers running outside along said post.
4. Tensioning device according to claim 1 together with supports on said pressure housing carrying guide rollers running outside along said post.
5. Tensioning device according to claim 1 wherein there are at least two tensioning elements arranged one above the other and rigidly with one another by means of braces to form a tension frame.
References Cited UNITED STATES PATENTS 587,274 7/1897 Rue 6139 X 764,798 7/1904 Diebitsch 6l-39 X 891,897 6/1908 Astrom 61-39 X FOREIGN PATENTS 135,989 10/ 1929 Switzerland.
J. KARL BELL, Primary Examiner U.S. Cl. X.R. 61-39