US3592420A

US3592420A - Mat for lining beams in mine constructions

Info

Publication number: US3592420A
Application number: US819661A
Authority: US
Inventors: Hans Reiter
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-05-07
Filing date: 1969-04-28
Publication date: 1971-07-13
Anticipated expiration: 1988-07-13
Also published as: DE1758284B1; FR2007989A1; GB1210488A

Abstract

The disclosure relates to a wire mesh mat intended for the lining of supporting beams in mine roadways and tunnel constructions, and consisting of mat sections each having longitudinal and transverse rods welded together at their intersection points, the longitudinal rods having hooks at their ends, while the longitudinal rods are assembled together in pairs and have transverse rods at both ends of the mat section, whose welded joints are subject to shearing stress, but the spacing distances at opposite ends being different so that the mat sections can be successively interengaged with each other.

Description

United States Patent [72] inventor Hans Reiter [56] References Cited gwlomstrasse 23, 4354 Damn, UNITED STATES PATENTS ermany pp No- 819661 l l\Yergsenbom 245/10 Ffled APTI281969 2,315,180 3/1943 onh 245/9 Patented July B 197 i Art ur 94/13 32 Priority May 7, 1963 FOREIGN PATENTS 33] Germany 559,542 2/ 1944 Great Britain 245/8 [3 l 1 P 17 58 284': Primary Examiner-Richard .l. Herbst Attorney--Malcolm W. Fraser ABSTRACT: The disclosure relates to a wire mesh mat intended for the lining of supporting beams in mine roadways and tunnel constructions, and consisting of mat sections each MAT FOR LININGSBEAMS IN MINE having longitudinal and transverse rods welded together at CON STRUCTIO N their intersection points, the longitudinal rods having hooks at 2 Chums, 8 Drawmg their ends, while the longitudinal rods are assembled together [52] 0.8. CI 245/9, in pairs and have transverse rods at both ends of the mat sec- 94/13 tion, whos e welded joints are subject to shearing stress, but the [51] Int. Cl Efllc 5/16 spacing distances at opposite ends being different so that the [50] Field 0! Search 245/8, 9, mat sections can be successively interengaged with each other.

MAT FOR LINING BEAMS IN MINE CONSTRUCTIONS BACKGROUND OF THE INVENTION In such wire mesh mats the longitudinal rods are under severe tensile stress and are dimensioned accordingly. On the other hand the transverse rods serve essentially for holding the mat together and accordingly are usually designed of lighter construction. The ends of the longitudinal rods must therefore be so designed that they can withstand the forces up to the limit of their parting strength, in order that there shall be an optimum utilization of the material of which they are made. On the other hand, however, these forces must be capable of being transmitted from an adjacent mat, as well as from a support beam itself, to the longitudinal rods.

It is already known, in a mat of the above-mentioned construction, to locate the joint between the ends of the mats adjacent to the support beam. For this purpose the longitudinal rods assembled together in pairs are provided with obtuse angled bends, and at one end of the mat, where the ends of the longitudinal rods are spaced apart at a greater distance than at the other end of the mat, they are provided with hooks having substantially rectangular jaw apertures. Such mats are capable of being provided with additional protection at the forward end of the roadway, and satisfactory suspension of such mats can be ensured, while under load they exhibit a certain yieldability because, at the ends of these mats where the longitudinal rods are spaced farther apart than at the other ends the transverse rods first of all approach each other before they are stressed under tension. However, there is a disadvantage that, in consequence of the special joint construction which is adopted, the hooks are placed only at one end of the mats and therefore the engagement at both sides of the two support beams which are bridged over by the mat, is not possible, and as a consequence the advantageous firm connection between the mats and the beams is essentially lacking.

It is also already known, in wire mesh mats having longitudinal rods assembled in pairs, to provide both ends with hooks, said hooks at one end of the mat having a substantially rectangular jaw, and the opposite end of the mats having hooks with an acute angled jaw for the purpose of at least partial engagement of the support beam. However, such mats may not be suspended within each other, and also cannot be provided with additional protective means at the forward end of the roadway. They are, however, particularly safe against disturbance. For this purpose the lowest parts of the openings formed by the two hook jaws are at a greater spacing distance from each other than the distance between the outer edges of the two support beams, which are to be bridged over by the mat. By reason of the clearance thus provided the mat can be pushed back in order that the acute angled jaw can be brought into engagement with the support beam.

Finally, it has also already been proposed to weld at the ends of the longitudinal rods punched metal plate members of hook form. In this way, practically any desired degree of high shearing strength can be achieved in the hooks and accordingly sufficiently high tensile strengths can be achieved in the longitudinal rods. However, the manufacture of such mats is comparatively difficult.

SUMMARY OF THE INVENTION The present invention takes as its basic purpose the provision of a mat which permits progressive interengagement of a plurality of mat sections and at the same time affords the possibility of providing security at the forward end of the roadway, the construction also having bent ends of the longitudinal rods to achieve the advantageous secure connection between the mat and the support beams which are to be bridged over, and achieving at the same time a tensile strength of the mat connections which can if necessary be as large as the tearing strength of the longitudinal rods.

This is achieved in accordance with the invention in that, at one end of each mat section the hooks are designed in known manner with a substantially rectangular-shaped jaw and are provided at the opposite ends with hooks having an acute angled jaw providing at least partial engagement of the support beam, the arrangement being such that when the hooks having the rectangular jaw shape bear against the support beam, or shortly after a bending of these hooks, the transverse rods abut against each other.

By the adoption of this design of the wire grid mat sections in particular of the ends thereof which are to be connected together, there is achieved a coupling effect between both of the types of hooks in use with the transverse rods, whose welded joints are shearing stress, said two types of hooks being those having the rectangulanshaped jaws and the acute angled shaped jaws. At the same time, the result is achieved that a certain yieldability of the mat is retained, such yieldability being afforded on the one hand by the clearance inherent in the mat construction and on the other hand by a reduction in the spacing distance of the ends of the longitudinal rods from each other.

Moreover the mat sections retain the already mentioned advantage in mat construction of being proof against disturbance while having a comparatively low production cost and without making the manipulation of the mats more difficult.

Apart from this the result is achieved that each longitudinal rod is fully utilized, that is to say it can be subjected to stress up to the limit of its parting strength.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of two successive wire mesh mat sections after they have been arranged upon the support beams;

FIG. 1A is a side elevation of the structure shown in FIG. 1;

FIG. 2 is a plan view on a larger scale of the condition existing in FIG. 1 at one of the support beams with which are engaged two succeeding wire mesh mat sections;

FIG. 2A is a side elevation of the structure shown on FIG. 2;

FIG. 3 is a plan view showing the structure corresponding to FIG. 2, but at the end ofa first stressing phase;

FIG. 3A isa side elevation of the structure shown on FIG. 3;

FIG. 4 is a plan view showing the structure corresponding to that of FIG. 3 but in a second phase of the stressing, which may be followed finally by the destruction of the joint between the mat sections; and

FIG. 4A is a side elevation of the structure shown on FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the figures of the drawing corresponding parts are indicated by the same reference characters.

For the purpose of lining a succession of support beams l, 2 of a roadway in a mine working, a number of similarly designed wire mesh mat sections 3 are employed, which are connected to the support beams and are connected together at their ends in the manner to be described hereinafter.

Each of these wire mesh mat sections comprises longitudinal rods 4 and transverse rods 5. The longitudinal rods and transverse rods are welded together at their intersection points, of which one is indicated at 6.

The ends of the longitudinal rods 40, 4b are assembled together in pairs proceeding across the width of the mat.

At one end of a mat section, namely the left-hand end in FIG. I, the assembly of the ends of a pair of longitudinal rods consists of a

bent portion

7a and 7b, these ends being directed towards each other so that the end portions of the longitudinal rods are closer together than are the central parts of the rods.

Moreover, at the left-hand end of the mat section the longitudinal rods are connected together by crossbars 8, these crossbars 8 being welded to the rods. At this end the

longitudinal rods

4a, 4b are provided with hooks 9 having substantially rectangular jaw openings 10.

At the opposite end the longitudinal rods are likewise provided with bent portions lla, llllb which are again turned towards each other. However, as contrasted with the bent portions 70 and 7b the distance between the bent ends of the longitudinal rods is greater, so that the ends of the rods carrying the crossbars 8 can be introduced between the ends having the

bent portions

11a, 11b.

The longitudinal rod ends 4c shown at the right-hand side of FIG. 1 are provided with a continuous crossbar l2 welded to said ends, in contrast to the arrangement of the longitudinal rod ends 4d at the left-hand end of the mat section.

Furthermore, the ends 4c of the

longitudinal rods

4a and 4b are provided with acute angled hook jaws 14 in such a mariner that these hooks can at least partially embrace the support beams.

In the practical example selected for description the support beams have a I profile, of which the flange 2a (FIG. 2) of the l profile beam is situated nearest to the wall face, such flange being partially embraced in the above-described manner.

As may be seen from FIG. 1 the spacing interval of the lowest point between the hook jaws l and 14 is greater than the distance between the bearing edges (2b and 2e on the support beam (FIG. 2).

In accordance with this arrangement, after setting up a support frame with the support beam 2, first of all the end 4d of one mat section can be hooked into the end 40 of the preceding mat section in such a manner that the short crossbars 8 and the hooked portions 4d support themselves upon the hooks in the part 40 and upon the cross bars 12. In this way also the mat provides itself with forward support. In this arrangement the mat must be retracted by an amount equal to the difference of the spacing between the deepest points of the hook jaws and the space between the appertaining edges of the support beam, so that as a result the acute angled hook portion 14 is brought into engagement with the support beam. As shown, the crossbars 8 are spaced from the appertaining crossbar 12 by a predetermined distance, which is indicated at the top of Fig. 2 by the reference a.

Upon applying stress to the longitudinal rods of the mat the distance a is progressively decreased until it is reduced to the value b (FIG. 3A). In that condition the acute angled hook jaws l4 and the right angled hook jaws l0 bear against the appertaining

edges

2b, 2c of the support bar 2. Up to this time the initial yieldability of the mat connection has been utilized.

If now further stress if applied to'the longitudinal rods of the mat sections then the hooks l0 and 14 are placed under stress. In this way the clearance b is put to use in such a manner that the short crossbars 8 bear against the adjacent surface of the continuous cross bar 12. This condition is shown in FIGS. 4 and 4A.

Thus, it is possible to design the arrangement in such a manner that only after the right angled hook jaw 10 comes to bear against the appertaining edge 2c of the support profile 2 is the clearance b fully utilized. This possibility has been assumed in the practical example according to FIGS. 4 and 4A. Thus, the rectangular hook jaw 10 has already begun to bend outwardly. There now comes into effect the joint action of the hook jaws l0 and [4 at the same time as the stressing of the welded joints of the

crossbars

8 and 12.

By way of modification from the practical embodiment described, the arrangement may be so devised that the clearance b has already been exhausted before the hook l0 begins to bend upwardly.

What I claim is:

1. A wire mesh mat for the lining of support beams in mine roadways and tunnel constructions comprising a plurality of sections joined in an end-to-end relationship wherein each section comprises longitudinal rods and transverse rods welded together at their intersection points, the longitudinal rods having hooks at their ends and being assembled together in pairs with cross bars at both ends of the section, the pairs of longitudinal rods having different spacings at opposite ends of said rods in order to allow one section to be interengaged in sequence with another section, longitudinal rods of the section being formed at each end with hooks, the hooks at one end being bent at an acute angle or otherwise formed for the purpose of at least partially embracing a support beam, and the crossbars being so arranged that when t e hooks at the end opposite to the said one end bear against the support beam, or shortly after such hooks are subjected to bending strain, the adjacent cross bars of two interengaged sections bear against each other.

2. A wire mesh mat as claimed in claim 1 wherein the hooks at the said opposite end are bent at substantially a right angle.

Claims

1. A wire mesh mat for the lining of support beams in mine roadways and tunnel constructions comprising a plurality of sections joined in an end-to-end relationship wherein each section comprises longitudinal rods and transverse rods welded together at their intersection points, the longitudinal rods having hooks at their ends and being assembled together in pairs with cross bars at both ends of the section, the pairs of longitudinal rods having different spacings at opposite ends of said rods in order to allow one section to be interengaged in sequence with another section, longitudinal rods of the section being formed at each end with hooks, the hooks at one end being bent at an acute angle or otherwise formed for the purpose of at least partially embracing a support beam, and the crossbars being so arranged that when the hooks at the end opposite to the said one end bear against the support beam, or shortly after such hooks are subjected to bending strain, the adjacent cross bars of two interengaged sections bear against each other.