US3527319A

US3527319A - Safety net

Info

Publication number: US3527319A
Application number: US850523A
Authority: US
Inventors: Eric L Pedley
Original assignee: Pedley-Knowles and Co
Current assignee: Pedley-Knowles and Co
Priority date: 1969-08-15
Filing date: 1969-08-15
Publication date: 1970-09-08
Anticipated expiration: 1987-09-08

Description

SPt 8, 1970 E. 1 PEDLEY 3,527,319

SAFETY NET Filed Aug. 15, 1969 4 sheets-sheet 1 JNVENTOR. ERIC L. PE DLEY ATTORNEYS E. L. PEDLEY Sqn. s, 1970 SAFETY NET 4 Sheets-Sheet. 2

Filed Aug. 15. 1969 f N OPN n SEI S1282 INVENTOR. ER|c ,L.PEDLEv WMA/MPM ATTORNEYS SSPL 3, 1970 E. l.. PEDLEY 3,527,319

SAFETY NET Filed Aug. l5. 1969 l 4 Sheets-sheet 4 im' Pipa-'r 3,527,319 SAFETY NET Eric L. Pedley, Kentfeld, Calif., assignor to Pedley- Knowles & Co., San Francisco, Calif., a corporation of California Continuation-impart of application Ser. No. 757,825, Sept. 6, 1968. This application Aug. 15, 1969, Ser.

Int. Cl. A62b 1/22 U.S. Cl. 182--139 17 Claims ABSTRACT OF THE DISCLOSURE A rectangular safety net of diamond mesh that includes an edge rope, which edge rope is connected with the net along its edges. Means, including said edge rope is provided for suspending said net from the structural framework of a building across an area above which work is being done, and the construction of which net is such that its length or width may be increased or decreased to accommodate the net to variations on length or width of said area.

This is a continuation-inpart of application Ser. No. 757,825, filed Sept. 6, 1968.

SUMMARY OF THE INVENTION In the erection of buildings, it is usual for building codes to specify safety requirements, one of which is the provision of means to protect the workmen from falling through open areas. A commonly adopted means is the construction of a wooden deck, or floor, below such area. The installation of such a deck is costly and time consuming, and while the decks so constructed may limit the fall distance, they do not necessarily prevent fatal injuries.

The use of safety nets has been proposed, but heretofore such nets have each been tailored for the specific area across which it is to extend. As the nets are quite costly, it has not been economically feasible to make. a separate net for each area of different size. Also, where the use of nets has `been attempted, the nets have been of the square mesh type having an edge rope secured thereto that limits the two dimensions of the net. The procedure for hanging such nets has been to first secure a wire rope to the building structure around the area across which the net is to extend. This, in itself, is a time-consuming step. The next step is to hook the edge rope on the net to the wire rope.

One ofthe objects of this invention is the provision of a net of the diamond mesh type in which the outline of the net is defined by one of the return bends of the rope defining the outer row of mesh openings, and which net includes an edge rope along said return bends connected therewith for longitudinal movement thereof to said return bends and to the net.

Another object of the present invention is to provide a single net that will automatically and etiiciently adapt itself to fit different areas `within relatively wide limits as to breadth and width, and other objects are the improved means of performing the net hanging operation for suspending a net across areas of different dimensions, and an improved method of suspending a net. Other objects and advantages will appear in the description and drawings.

DESCRIPTION OF DRAWINGS For the drawings, FIG. 1 is a plan view of a representative net, in 'which the mesh ropes are indicated in single lines, and the edge rope and means for connecting the latter to the mesh ropes are indicated in double lines.

FIG. 2 is an enlarged, fragmentary plan view of struc- "United States Patent O "ice 3,527,319 Patented Sept. 8, 1970 ture at one corner of the net of FIG. l, including the edge rope.

FIG. 3 is an enlarged, fragmentary plan view of one of the two corners of the net of FIG. 1 that are adjacent the corner shown in FIG. 2.

FIG. 4 is an enlarged, fragmentary plan view of the other corner of the net of FIG. l, that is generally adjacent to the corner shown in FIG. 2.

FIG. 5 is an enlarged plan View of the structure of the corner of the net of FIG. l that is diagonally opposite to the corner shown in FIG. 2.

FIG. 6 is a modification of the structure shown in FIG. 2.

FIG. 7 is a plan view of an installed net, the posts and beams of the building structure being simplified, and the mesh ropes, being merely indicated along the edge ropes. The view is broken in length and width.

FIG. 8 is an enlarged cross-sectional view along line 8 8 of FIG. 7.

FIG. 9 is a semi-diagrammatic view illustrating a method of installing the net of FIG. 1, the mesh ropes being omitted, and the edge rope and other ropes being in single lines except at the corners of the net and the hooks at the ends of the hoisting lines.

FIG. l() is an enlarged elevational vie'w of a portion of FIG. 7 as seen from line 10-10 of FIG. 7.

FIG. ll is an enlarged, fragmentary plan view of a modified structure of a corner similar to that of FIG. 2.

FIG. l2 is an end view of one of the double thimbles used in the net.

FIG. 13 is a part sectional, part elevational view of the thimble of FIG. 12.

FIG. 14 is a top plan view of a net represented in the same manner as the net of FIG. 1 and showing additional rings connected with the mesh rope and extending across the net for use with the same edge rope in areas of greater variation than will be accommodated by the net of FIG. l.

FIG. 15 is an enlarged fragmentary view of one corner of the net of FIG. 14 at one end thereof showing a tie rope connected with the net for lifting the net at said corner by a hand line such as indicated in FIG. 9.

FIG. 16 is an enlarged fragmentary view of the other corner of the net of FIG. 14 at the same end of the net showing a tie rope similar to that of FIG. 15, also connected with a lifting line.

FIG. 17 is a fragmentary top plan view of one of the connections between a pair of panels of the net of FIG. 14.

FIG. 18, is an enlarged fragmentary perspective view, partly in cross section, of one of a transverse row of the rings shown in FIG. 14 intermediate the ends of the net, showing the portion of the net at one of the sides of said row of rings thereon back onto the remainder of the net, when the net is supported by the edge rope extending through said rings to extend across a substantially smaller area than the area within the outline of the net as shown in FIG. 14.

FIG. 19 is a semi-diagrammatic enlarged, fragmentary plan View of the lower left-hand corner of the net as seen in FIG. 1 showing the tightener clamped to the edge rope and with the edge rope` connected with a clamp secured to a portion of the building frame.

FIG. 2() is an enlarged top plan View of a clamp adapted to be secured to a column at any level, instead of a beam, said column being shown in cross section.

FIG. 2l is a side-elevational view of the clamp of FIG. 19.

DESCRIPTION OF PREFERRED EMBODIMENTS The four corners of the rectangular net shown in FIG. l are respectively generally designated A, B, C,

3 and D. The corners A, D are at two diagonally opposite corners.

'Ihe net is of the diamond-mesh type in which the mesh ropes extend obliquely from the edges, and which ropes are tightly secured together at their crossing points.

In the net, when formed, the mesh ropes 1 cross each other at substantially right angles, and the'edges of the mesh portion of the net are dened by ninety-degree return bends 2 of the outer rows of mesh along the outer mesh openings. The mesh openings are designated 3.

A net of the foregoing character may be expanded in the planes thereof, in either one of its two dimensions approximately 20 percent, without undesirable distortion of the mesh, there being a proportionate decrease in the other of said two dimensions than the one in which expansion is effected.

A ring 4 is xedly secured to each return bend 2, providing a row of such rings along and projecting outwardly of the net along each of the edges of the latter. The rings and rope at each return bend may extend through a double thimble, such as indicated at 5 in FIG. 13, lashed in a fixed position relative to the return bend, by ber glass strands and an epoxy plastic substantially as described in U.S. Letters Patent No. 3,091, 016 of May 28, 196-3, and the same type of lashing that secures the mesh ropes together at their crossing points 6.

A rope 7, preferably of wire, loosely extends through rings 4 along each edge of the net, and which rope may be continuous around the net from approximately corner D, and is formed with a xed loop 8 at corner A, said latter corner being diagonally opposite to corner D (FIGS. l, 2).

A length of said rope 7 extends from corner A through rings 4 to corners B and C, and loosely through a ring 9 at each of said latter corners, which ring 9 is between a pair of adjacent rings 4 at each of said corners. The edge rope 7 is slidable through said rings 9 and said rings will always remain between the same adjacent pair of rings 4, irrespective of whether or not the net is expanded in either of the two dimensions.

The lengths of the wire rope 7 that extend loosely through rings 9 at corners B, C, extend to, or substantially to corner D, and a chain 10 at corner D may be spliced at its ends to the terminal ends of the wire rope 7. This chain is preferably a single chain of sufcient length so as to provide for any desired change in the dimensions of the net and to facilitate tightening the edge rope, as' will be explained later on. The chain 10 normally extends between a pair of adjacent rings 4 at corner D, although it may also extend through either or both of such rings,

or more.

In FIG. 7, structural steel vertical posts 13 are indicated at the corners of a rectangular area outlined by horizontally-disposed pairs of I beams 14, that, in turn, generally dene the sides of a rectangular open area across which the net is to be positioned. Beams 14 are along the sides of greatest length and beams 15 are along the shorter sides of said area, where the open oor area is oblong.

A beam clamp 16 is adapted to be secured to beams 15 adjacent each corner post 13, or at any point along the beams. Each clamp comprises a pair of opposed jaws 17 (FIG. 8) recessed on their opposed sides at 18 to recess coplanar flanges 19 of one of the two pairs of said beam. Said jaws each have an ear 20 projecting therefrom in spaced opposed relation when said anges are in recesses 18 and a bolt 21 extends through coaxial openings in the pair of ears tightening the jaws 17 on the beams when a nut 22 on one end of each bolt is tightened.

Extensions 23, rigid with each jaw 17, project therefrom for securement of a conventional shackle 24 or a hook to each extension, with the extensions each having an opening 25 therein for such shackle or hook.

By the above structure, clamps 16 are adapted to be releasably secured to beams of dilerent sizes and to be adjustably clamped thereto at any desired position along the beams. Said clamps may be clamped to either or both of the

beams

14, 15.

The extensions 23 project laterally outwardly to opposite sides of each I beam making openings 25 therein readily accessible for securement of shackles or hooks thereto.

In FIGS. 7, 10, a clamp 26 is shown, which clamp has the same beam clamping structure as clamps 16, for securing each clamp to an I beam, but extensions 27 are provided to project laterally to one of the sides of the clamp, instead of projecting from the ends. The extensions 27 will be spaced from the beam to which it is attached so that the opening 28 in each extension will be readily accessible for a shackle or hook, but the extensions will be disposed within the connes of the vertically projected outline of the beam.

Beam clamps 16, or 26, as seen in FIG. 7 are respectively secured to

beams

14, 15 adjacent to the ends of the latter, and adjacent to posts or columns 13.

For convenience of description, the posts 13 will be designated A', B', C', and D' and which posts are respectively adjacent to the corners of the net having the same letter designations.

Referring to FIG. 9, in installing the net, a pick-up line 29 may be connected by a hook 30, with corner A of the net, and which pick-up line 29 extends upwardly to a point adjacent post A' and at or above the level where the net is to be installed. The corner A or the net is then hoisted by pick-up line 29 by any suitable means connected with such line, such as a crane or by hand, and a shackle 24 then secures the loop 8 to an extension 23 of the clamp 16.

Pick-up lines 32 are respectively connected to the net, or rings 9, by hooks 33 and said corners B, C may then be successively or simultaneously hoisted in the same manner as corner A, and shackles 24 secure said rings 9 to clamps 16 that are adjacent to posts B', C'.

A hoist line 34 is connected by a hook with chain 10, and the corner D of the net is hoisted to the level of the other corners and to a point adjacent to post D', after which the portion of edge rope 7 that is to extend along the beam 14 that connects with post D' is connected with a conventional comealong 36.

Comealong 36 may be connected at one end with the clamp 16 that is adjacent post D', either with bolt 21 or the comealong may be connected with an extension 27 of a clamp 26 that, in turn, is connected with beam 14. The tightening chain 37 of the comealong may then be connected by a hook with a link of chain 10 that is adjacent the splice 38 between the chain and the portion of edge rope 7 that is to extend along beam 14.

The comealong may then be actuated to tighten the length of edge rope 7 that extends to corner D by way of ring 9 at the corner B, and when so tightened, a link of the tightened portion of the chain is secured to the clamp 16 by a shackle 39 (FIG. 7) or conventional grab hook.

The chain 37 of the comealong is then released and said chain is then hooked to the splice loop 38 and the end of the edge rope 7 extending to chain 10 by way of the ring 9 at corner C, which is the position shown in FIG. 7. Again the comealong 36 is actuated, and the rope 7 connected therewith is tightened. After tightening, a link of chain 10 is connected by shackle 40 or a grab hook to the clamp 16 that is adjacent to post D'. Any desired number of chokers 41 may draw the edge rope 7 closer to

beams

14, 15, if desired, but in any event, the net will extend across the area Within the outline of the beams within the range of the flexibility of the net.

It should be noted that the function of the chokers, where used, is to draw the edge of the net closer to the beams should there be a greater space between the edge rope and the beams than is desired. The net itself is normally suspended from its corners, and if further Suspension should be desired, as in the case of a net of unusual length, it is obvious that extra clamps 16 may be clamped along any of the beams and connected by a shackle or hook with the edge rope 7 between any pair of rings 4 or return bends 2.

Whether the clamps are below the beams or above the latter depends upon the conditions. Where clamps 26 are used instead of clamps 16, the extensions 27 will be closer to the beams, and the edge rope may be within the confines of the vertically projected outlines of the respective beams.

The edge rope 7 in FIGS. 1 7 is continuous, the loop 8 being formed in the rope.

In FIG. 6 two edge ropes 43, 44 are shown, rope 43 having a loop 45 at one end and a loop 46 is at the end of rope 44. rll`hese loops are connected by a shackle 47 with a

clamp

16, or 26 adjacent post A', instead of loop 8. The rest of the structure may be the same.

While chain 10 provides a plurality of links, any one of which is adapted to be quickly engaged by a conventional grab hook on the chain 36 of the comealong or by

shackles

39 or 40 for connecting to clamp 16 or 26, it is to be understood that the edge rope 7 may be drawn taut at corner D and the end of the rope itself doubled on itself at corner D to form a loop corresponding to loop 8, through which loop a hook or shackle on

clamp

16 or 26 may extend to hold the wire rope taut.

Also, it is to be understood that the shackle connections between the edge rope or ropes, and the clamps 16 are examples of safe connections, although hooks such as are indicated at 33, 34 on the hoist lines, or on the chokers 41 may be used.

While the rings 4 are preferable for loosely connecting the mesh ropes of the outer row of mesh openings with the edge rope 7, thereby reducing wear on the ropes, it is obvious that the edge rope could extend through the outer mesh openings and engage the mesh rope thereof at the return bends of the latter. Also, the edge rope may be of ber, but the wire rope is preferable.

Also, the edge rope, designated 49 in FIG. 1l, could be continuous from one end at corner D to the other end at corner D, and slidably extend through a ring 50 (FIG. l1) at corner A, in which case the comealong at corner D would be connected with only one end of the rope for tensioning the net. However, ring 50 would be between the same adjacent pair of rings 4, as in the other figures.

As an example of the adaptability of the net for different areas, assuming the net in its normal shape is 21' x 38', the net will obviously be adapted to be suspended across approximately the same open area. In addition, by the present construction, an automatic approximately 20 percent increase or decrease from normal is adapted to be accomplished. The length of the edge rope will vary for different areas. Where the net is normal, the edge rope is approximately 118' in length and where adjusted to 16 x 46', the length is approximately 124', and when 26' x 3l', the length is 114'.

Preferably an additional approximately 10 percent of the maximum length of 124' is provided for convenience of hanging the chain being included. By gathering the slack at one end the net may be used for even smaller areas. The diagonal or diamond mesh structure as combined with the edge rope, as described, enables this relatively wide variation.

The net rope 1, being continuous at the return bends 2, and each of the rings 4 being closed, special double thimbles 5 (FIGS. l2, 13) are used to connect the rings to the return bends.

Each of these thimbles comprises a Shell of metal or other suitable material which, when closed, provides a through passageway 52 adapted to receive a ring 4 and a return bend 2 of the rope 1 in side-by-side coplanar relation.

The walls of the passageway 52 in the plane in which each ring 4 and return bend 2 are disposed, are curved to substantially conform to the linear and cross-sectional contours of the ring and return bend, and the walls are outwardly at the open ends of the passageway.

One side of each double thimble is separated at 53 (FIG. 12) although not necessarily spaced apart, after the ring and return bend are in the passageway. The thimble is normally spread to open position as indicated in dot-dash lines 54 (FIG. l2) so that the ring and return bend may be inserted into the thimble through the opened side, after which the thimble is bent to Closed position, as in full line in FIG. 12, and thereafter the berglass strands freshly coated with epoxy resin and hardener lash each thimble in closed position and firmly lash the rope and ring to the thimble. When the resin hardens, each ring 4, return bend 2 and thimble provide an inseparable union.

The method that is involved in suspending the edge rope of the structure defined comprises the steps of suspending said net at each of its return bends 2 on an edge rope extending along each edge of said net for sliding of said return bends relative to each other `and to said edge rope longitudinally of the latter, and connecting the edge rope at each corner A, B, C, D at its corresponding structural members A', B', C', D from a point along said edge rope that is between and adjacent to a predetermined adjacent pair of said return `bends at each corner of said net for sliding movement of said edge rope longitudinally thereof at said point relative to the structural members of at least one diagonally opposite pair of structural members such as B' and C', and thereafter drawing the edge rope taut along each edge of said net from a point adjacent to one of the other pair of diagonally opposite structural members, such as D', after which the tauted edge rope is secured taut along the edges of the net.

Whether the structure of FIG. l, 2, 6 or l1 is employed, or whether the edge rope extends through rings r4 or through the return bends 2, the same method is employed and the dimensions of the net at a right angle to each other and parallel with its edges, will substantially conform to one of a plurality of different rectangular dimensions of the area enclosed by the taut edge rope although the sides need not be parallel.

Insofar as the net itself, independently of the method of suspending it is concerned, basically it is of diamond mesh structure having outer edges defined by the return bends of the mesh openings along said edges and broadly, it includes an edge rope along each edge of the net slidably connected with said net at each of said return bends for movement of the return bends relative to each other along the edge rope with which the return bends are slidably connected. The return bends of an adjacent pair thereof are spaced apart and positioned, respectively, along adjacent lengths of the edge rope of said net at each corner of the latter, and the edge rope along the adjacent edges of the net that extend from the respective corners of one pair of diagonally opposite corners, as at B and C, are continuous to one of the corners of the other diagonally opposite corners, such as A and D, for movement of the edge rope longitudinally thereof relative to said adjacent pair of diagonally opposite corners B and C.

The foregoing structure broadly describes all forms of the net disclosed, whether the edge rope is continuous from end-to-end as in FIGS. l, ll, or is a pair of edge ropes as in FIG. 6. In any case, tauting the rope or ropes from the corner D will effect an automatic dimensioning of the rope for extending across one of dilerent rectangular areas.

In describing the net shown in FIGS. 14-18, the same numerals will be used as in the net of FIGS. 1-13 to identify elements having the same structure and function.

The net of FIGS. 14-18 has the same diamond or diagonal mesh arrangement of FIG. 1 in which the outer edges are defined by return bends of the mesh rope, and rings 4 are secured to said return bends by double thimbles 5 lashed in position.

Wire rope 7 constitutes the edge rope and loosely extends through the rings 4. Said edge rope is preferably in two lengths and loops or eyes 46, 47, as shown in FIG. 6 are at one of the corners A, the four corners being designated A, B, C, and D. The lengths of the edge rope 7 respectively extend continuously to and past corners B and C to corner D, the latter being diagonally opposite to corner A.

In the present invention, a tie rope 60, which may be in the form of an endless loop, extends through and connects the pair of rings 4 adjacent each corner A and B. The net is lifted by pick-up lines corresponding to pick-up

lines

29, 32, the

hooks

30, 33 engaging the tie ropes or loops 60 at each of the aforesaid to corners of the net.

The use of ropes 60 connecting the rings 4 adjacent each of said corners prevents the net at said corners from slipping down the edge rope during the initial hoisting of the net from either of corners A, B before the net is hoisted at corners C, D (FIGS. 14, 15, 16).

There is no need for such tie ropes at corners C and D inasmuch `as the latter are normally elevated last, and the hooks on the pick-up lines can be connected with the mesh rope at said corners after the edge rope at said corners is secured to clamps on the building structure.

The lengths of edge rope 7 at corner A are bent on themselves to form the loops or

eyes

45, 46 that are secured by conventional rope or cable clamps 61, said eyes being connected to a shackle 47 (FIG. 6) or 24 (FIG. 7) that, in turn, is connected to a clamp 16.

The edge rope 7 at comers B and C may extend directly around the pin of a conventional shackle 24 that is connected with a clamp 16 to one of the beams 14 at each of said corners (FIG. 14).

The free ends of the lengths of `edge rope 7 at corner D may also be formed to provide loops 62, 63 (FIG. 14). The beam clamp 64 at corner D may have an extension 65 provided With a pair of openings, instead of only one, for receiving a pair of shackles 24, each extending through one of the openings of said pair, and each shackle connects one of the loops 62, 63 with the extension 65 of clamp 64.

The lengths of edge rope 7 extending to corner D may be tightened to give the net the desired degree of tautness by use of chains and Ia comealong, as described with respect to FIG. 7, or the comealong may be connected with a rope or cable clamp 66 (FIG. 19) secured on edge rope 7, and when the edge rope is drawn taut, the free end portion of the edge rope between clamp 66 and the corner D is looped about the pin of one of the shackles 24, to form one of the loops 62, 63 and a cable clamp 67 secures the loop closed. This tightening is applied to each of the lengths of the edge rope.

The net of FIG. 14 is oblong, `and assuming its dimensions are 33 x 206" when the mesh rope denes square mesh openings, said net is adapted to adjust itself to any width from approximately 16' to 26' and any length from approximately 16 to 38 which will enable a net of one size to accommodate itself to the majority of areas encountered in a building structure where protection is required.

To accomplish a wide variation, the net of FIG. 14 is provided with a plurality of spaced, parallel rows of rings 68 extending transversely across the net, relative to its length, and which rows are at the end of the net adjacent the end of the net having corners C, D.

Preferably, the net of FIG. 14 is formed from separate panels. In FIG. 14 there are seven panels 69-75 with panel 69 between the rings 4 at the end of the net extending between corners C, D, and three

panels

70, 71, 72, respectively, between the next successive adjacent pairs of rows of rings 68.

Double thimbles 78 not only connect the rings 68 to the mesh rope of the panels, but they connect the adjacent mesh of the panels along the aligned corners of the mesh at the adjoining edges of the panels of adjacent pairs.

These double thimbles have the same structure as the double thimbles 5, being open ended split sheets (FIGS. 10, 13) lashed closed about the mesh rope and rings 68 by fiberglass and epoxy resin.

The

panels

73, 74 and 75 are secured together by double thimbles 79 of the same structure as thimbles 68, but no rings are held by these thimbles.

For purpose of clarity, in FIG. 14 the proportions of the mesh openings relative to the dimensions of the net are much greater than in actual practice. Each side of each mesh opening may be only approximately 6 inches in an actual net.

The mesh rope in each panel is secured together at its points of crossing 80 by fiberglass and epoxy resin in the same manner as indicated at 6 in FIG. 2.

By forming the net in panels, the making of a net is expedited, as well as the making of nets of different sizes for special requirements.

Assuming the net of the dimensions of FIG. 14 is to be used to extend across an open area within the range of say 206" x 21, the length of the edge rope 7 extending between corners C, D is released from rings 4 along the end edge of the net, and from the rings 4 along the side edge of the net extending from corner C to the row 81 of rings that connects panel 72 with panel 73. The other length of edge rope 7 extending along the side of the net from corner D to row 81 is also released from rings 4. Clamps 67 would be removed to facilitate this release. The length of the edge rope 7 that has been released from corner C to row 81 is then rethreaded through the rings 68 of row 81, and then the said two lengths of the edge rope are tightened in the same manner as described for the full area net, and the surplus panels 69-72 are folded back onto the tensioned panels 73-75 and the free lengths of edge rope 7 may be also positioned on panels 7.3-75 or clamped to the edge rope along said panels to keep them out of the way.

It is pertinent to note that the rings 68 connect the return bends of the adjacent pairs of

panels

70, 71, 72, 73 at their return bends, hence end rings of each row bear exactly the same relation to the adjacent ring 4 through which the edge rope 7 extends for supporting the shortened net, as the relation between the adjacent rings 4 at corners C and D.

The foregoing described procedure may be followed with respect to any of the other rows than row 81, according to the dimensions of the area across which the net is to be positioned.

Normally the dimensions of the area is dictated by the lengths of the beams between the columns at the corners of the area. Whether the beam clamps are secured to the beams 14 or beams 15 is optional, but they are normally positioned adjacent to the columns.

There are instances Where it is desirable to position a net where the vertical distance between the beams, or the distance between the working level and the beams available for a net is greater than normal. Or it may be found desirable to connect the corners of the net closer to the columns at the corners of the area across which the net is to extend. In such instances the clamps shown in FIGS. 20, 21 are provided.

Each of such clamps is generally designated 82, and is quite similar to the clamps 16 in that each has a pair of

flange gripping jaws

83, 84 formed with recesses 85 for receiving a pair of the coplanar flanges 86 of a column having an H cross-sectional contour (FIG. 20). Each jaw includes ears y87 corresponding to ears 20 of each clamp 16, and a bolt 88 extends through aligned openings in the ears for tightening the jaws on the anges 86.

The plates 89 of a pair thereof are welded to opposite edges of each of the

jaws

83, 84 so that said plates are horizontal and in vertically spaced relation when the clamp 82 is secured on a column. The pairs of plates 89 respectively secured to

jaws

83, 84 project outwardly of said jaws away from the column when the clamp is secured to a column, and the plates of each pair are apertured for a vertical pin or bolt 90 positioned relatively close to the column.

Edge rope 7 may extend around one of the bolts on each of the clamps at one side of each column at corners B, C as indicated in FIGS. 20, 21, and the pins at one side of each column at corners A, D are adapted to each extend through the loops at the ends of the two lengths of the edge rope when the lengths have been tightened. The pins on the other jaw of each clamp are adapted to be used for hanging another net in an adjacent area. It is seen that the net may be positioned at any desired level independently of the beams by use of clamps 82.

The adjustability of the net of FIG. 14 to be quickly installed in a position to extend across each of the open areas of widely different dimensions has encouraged the acquisition and use of the nets under conditions Where there may be a reluctance to tie up an investment in nets having a lesser range of adjustability, irrespective of the far greater protection a net provides as distinguished from boarding over open areas. In each instance the time required for installing a net is far less than the time required for boarding over a corresponding area.

At the lower-righthand corner of FIG. 14, different broken line positions of the clamp 16 at corner C are indicated for different threadings of the edge rope 7 through the rows of rings 68, and the clamp 16 at corner D would, of course, be in similar positions along the beam 14 that is at the left-hand side of the figure.

The different positions indicated are merely illustrative of different positions in which the net is of approximately the same tautness. Obviously the net may be more or less slack where used in certain areas without losing its effectiveness.

The present invention is not intended to be restricted to any of the precise dimensions given. The net structure that includes the supporting edge rope as defined in the claims is broadly the same in FIGS. 1 and 14 and functions in the same manner during and after installation.

I claim:

1. The method of suspending a rectangular safety net made of rope and of diamond mesh structure having outer edges defined by the return bends of the outer mesh openings of said net, in a position extending generally horizontally across an open, substantially rectangular area having a stationary structural member adjacent each of its four corners, comprising the steps of:

(a) supporting said net at each of said return bends on an edge rope along each edge of said net for movement of said return bends relative to each other and to said edge rope longitudinally of the latter,

(b) connecting the edge rope at each corner of said net at one of said structural members from a point along said edge rope that is between and adjacent to a predetermined adjacent pair of said return bends at each corner of said net for movement of said edge rope longitudinally thereof relative to the structural members of at least one pair respectively at diagonally opposite corners of said area,

(c) drawing the edge rope taut along each edge of said net from a point adjacent to one of the pair of structural members at one of the other pair of diagonally opposite corners of said area, whereby the dimensions of the net at right angle to each other parallel with its edges will substantially conform to one of a plurality of different rectangular dimensions of different areas across which the net is adapted to extend,

(d) securing said edge rope at at least one of the said pair of structural members at one of said other pair of diagonally opposite corners of said area.

2. A safety device to be positioned generally horizontally across an open, generally rectangular area having stationary structural members adjacent the corners thereof comprising:

(a) a rectangular rope-net of diamond mesh construction providing two pairs of diagonally opposite corners and an outer row of mesh openings along each of its edges having return bends of the mesh rope of said outer rows defining the outer edges of said net,

(b) net-suspending means for suspending said net generally horizontally across such area including an edge rope along said edges connected with said return bends for suspension of said net from such stationary members at the corners of said net,

(c) said edge rope being continuous at one pair of said diagonally opposite corners, and each of said return vbends being connected with the length of the edge rope adjacent thereto for movements of said return bends relative to each other and to the edge rope longitudinally of the latter.

3. In a safety device as defined in claim 2;

(d) said means for suspending said net including ropeengaging means at each of the corners of said net for connecting said edge rope with said structural members, and the edge rope at said two diagonally opposite corners of said net being slidable longitudinally thereof through to said rope-engaging means when the latter are connected to said structural members.

4. In a safety device as defined in claim 3;

(e) the return bends of an adjacent pair thereof being at opposite sides of the rope-engaging means at each corner of said net for retaining said rope-engaging means in a position between the return bends of said adjacent pairs.

5. In a safety device as defined in claim 2;

(d) connecting means lixedly secured to each return bend having a passageway through which said edge rope is freely slidable for said movement of said return bends relative to each other and to said edge rope,

(e) the connecting means of an adjacent pair thereof being at opposite sides of the connecting means on the return bends at the corners of said net at said two diagonally opposite comers of said area.

`6. In a safety device as defined in claim 3;

(e) means rigidly fixed on the lengths of said edge rope extending to one of the other two diagonally opposite corners of said net for connection with the rope-engaging means at said last-mentioned corner for holding said lengths of said edge rope against longitudinal movement of said edge rope relative to the structural member at said last-mentioned corner when said rope-engaging means is connected with said structural member.

7. In a safety device as defined in claim 2;

(d) said net-suspending means including rings secured to the return bends along each edge of said net through which said edge rope slidably extends for connecting said edge rope with said net and enabling said movements of said return bends relative to each other and to said edge rope.

8. In a safety device as defined in claim 7;

(e) a pair of said rings being adjacent to and at opposite sides of each of the corners of said net,

(f) means connecting one of the pair of said rings at one of said diagonally opposite corners for engagement with a lifting line independently of said edge rope for lifting said net, when the latter is substantially collapsed, at said one of said diagonally opposite corners to a corner of the area across which said net is to extend to prevent said rings at said one of said diagonally opposite corners from sliding downwardly on said edge rope during said lifting of said net.

9. In a safety device as defined in claim 7;

(e) rings disposed in a row thereof spaced from and parallel with one of the edges of said net and secured to said net through which a length of said edge rope may be extended for providing a net adapted to extend across an open area of lesser size than when said length of said edge rope is extended through the rings along said one of the edges of said net.

10. In a safety device as defined in claim 9;

(f) a portion of said net including an adjacent pa1r of rectangular panels each extending between two of the opposite edges ofsaid net and the panels of said pair having adjacent edges defined by the return bends of the rope defining the mesh openings of said panels along said adjacent edges disposed in substantially meeting relation,

(g) a double thimble extending around and securing the return bends of said panels together along said adjacent edges.

11. A safety device to be positioned generally horizontally across an open, generally rectangular area having stationary structural members adjacent the corners thereof, comprising;

(a) a rectangular rope-net of diamond mesh construction providing two pairs of diagonally opposite corners and an o'ter row of mesh openings along each of its edges having return bends of the mesh rope of said outer rows defining the outer edges of said net,

(b) net-suspending means for suspending said net generally horizontally across such area including an edge rope along said edges and rings secured to said return bends through which said edge rope slidably extends,

(c) said edge rope being in two lengths respectively continuous at one pair of said diagonally opposite corners, and means at the other pair of said diagonally opposite corners for securing said two lengths to such structural stationary members when said lengths Iare tensioned for suspending said net across said area.

12. In a safety device as defined in claim 11;

(d) said net being in separately formed adjacent pairs of panels extending across said net between two of its opposite edges,

(e) the panels of each adjacent pair having adjacent edges defined by the return bends of the mesh rope defining the mesh openings along said adjacent edges,

(f) a double thimble extending around the adjacent return bends of each adjacent pair of panels securing said panels together against separation.

13. In a safety device as defined in claim 12;

(g) a plurality of rings in a row along at least one pair of adjacent edges of said panels, and

(h) the double thimbles connecting the return bends along said last-mentioned pair of adjacent edges with the rings of said row, to enable passage of said edge wire therethrough for suspending said net by said edge wire from corners at the ends of said row of rings.

14. In combination with stationary structural members defining the corners of a rectangular horizontal open area;

(a) a rectangular rope-net of diamond mesh construction providing two pairs of diagonally, opposite corners and an outer row of mesh openings along each f its edges having return bends ofthe mesh rope of said outer rows defining the outer edges of said net,

(b) said net being generally horizontal and extending across said open area with its corners being adjacent to said structural members,

(c) an edge rope extending along each edge of said net connected with each of said return bends for supporting said net from said edge rope when the latter is connected with said stationary members at the corners of said net,

(d) connecting means for so connecting the edge rope along each edge of Said net with each of said return bends for movement of said return bends relative to each other and to the edge rope with which they are connected,

(e) rope-engaging means for connecting the edge rope at each corner of said net to said stationary srtuctural members,

(f) said rope-engaging means at two of said diagonally opposite corners slidably supporting said edge rope for movement of said edge rope and said rope-engaging means relative to each other in a direction longitudinally of said edge rope.

15. In the combination as defined in claim 14;

(g) said connecting means each being a double thimble, or shell of metal or the like adapted to be bent along one side to a position open at the opposite side for insertion of a return bend and one side of a generally ring-like member therein, said shell, when closed, providing a through passageway for said ring and return bend, and the inside walls of said passageway generally conforming to the linear and cross-sectional contours of the outer surfaces of said return bend and ring,

(h) a ring-like member and a return Ibend being in each double thimble and said edge rope extending freely through each ring-like member,

(i) means for securing each double thimble to the ring-like member and return bend therein, and securing each double thimble closed.

16. In the combination as defined in claim 14;

(g) said rope-engaging means at one of the other two of said diagonally opposite corners, securing said edge rope to the structural member adjacent thereto and against movement of said edge rope relative to said rope-engaging means, and

(h) said rope-engaging means at the second of said other diagonally opposite corners including a comealong for releasably holding the portion of said edge rope between said last-mentioned corner and said one of said diagonally opposite corners taut.

117. In the combination as defined in claim 14;

(g) said rope-engaging means including a clamp releasably secured to a structural member at each of the corners of said area.

References Cited UNITED STATES PATENTS 590,083 9/1897 Alling 182-139 2,123,268 7/ 1938 Young 182--139 FOREIGN PATENTS 608,3 11 1/ 1935 Germany.

REINALDO P. MACHADO, Primary Examiner