US2132269A

US2132269A - Cable anchor

Info

Publication number: US2132269A
Application number: US39326A
Authority: US
Inventors: Frederick J Mchugh
Original assignee: Individual
Current assignee: Individual
Priority date: 1935-07-06
Filing date: 1935-09-05
Publication date: 1938-10-04
Anticipated expiration: 1955-10-04

Description

F. J. M HUGH CABLE ANCHOR Filed Sept. 5, 1955 2 Sheets-Sheet l Ema @"T' ATTORNEY @ci'. 4, 1938. I F. .J. MCHUGH CABLE ANCHOR Filed Sept. 5, 1935 2 Sheets-Sheet 2 Patented Oct. 4, 1938 PATENT OFFICE CABLE Frederick J. McHugh,

Application September In Canada 11 Claims.

This invention relates to cable anchors and particularly to improved means for anchoring individual strands of the large multiple strand cables used in the construction of suspension bridges.

According to one feature of this invention the cable strands are anchored at points equi-distant from the splay point of the cable by spheroidal disposition of the points of anchorage about a common center coinciding with said splay point. This arrangement lends itself .to the use of strands of equal length, thereby simplifying the strand manufacturing, pre-stressing and erection operations.

Another feature ofthe invention consists in the provision of a generally improved form of anchorage for the cable strands whereby the loads are transferred direct to masonry concentric'with the pull on said strands.

A further feature of the invention consists in fastening the cable strands to one or more anchor plates by suitable fittings which may be conveniently adjusted to selectively tension the strands in the event that the main centers of crossing or lengths of the strands are incorrect.

A still further feature consists in the provision of an improved form of multiple-strand cable anchorage which lends itself to economic fabrication and erection and'which may be conveniently incorporated in' the construction of a bridge pier or other masonry to which the loads on the strands are to be transferred.

Proceeding now to a more detailed description of the invention reference will be had to the accompanying drawings, which Fig. 1 is a view in side elevation of one form of cable anchorage provided in accordance with this invention.

Fig. 2 is a plan view of a one-piece anchor plate to which the cable strands are fastened so that the points of anchorage are spheroidally disposed about a common center coinciding with the splay point of the" cable.

Fig. 3 is a detail view showing the manner in which the cable strands are fastened to the anchor plate as well as the manner in which the anchor plate is fastened to the main frame and other elements of the anchorage.

Fig. 4 is a top plan view of the main frame appearing in Figs. 1 and 2.

Fig. 5 is a view in elevation of the rear portion of the main frame.

Fig. 6 is a view in elevation of the front tion of the mam frame. I

ANCHOR Dorval, Quebec, Canada 5, 1935, Serial No. 39,326 July 6, 1935 Fig. 7 is a view similar to Fig. 1 but showing a modified form of anchorage.

Fig. 8 is a sectional view along the line 8-8 of Fig. '7.

Fig. 9 is a fragmentary plan view taken as indicated by line 9-9 of Fig. 8.

Fig. 10 is a sectional view taken along the line |0--l0 of Fig. 9..

Referring more particularly to Figs. 1 to 6 inclusive, 5 designates a one-piece anchor plate to which the strands 6 of cable 1 are fastened by adjustable fittings generally indicated at 8. Each fitting 8 includes a threaded bolt 9 passing through an opening ID in plate 5, one end of said bolt being fitted with a nut bearing against a spherically curved surface l2 of the plate, the other end of said bolt being pivotally secured in the eye portion l3 of socket member I fixed to one of the cable strands 6. When plate 5 is anchored in place as hereinafter described the strands 6 may be selectively tensioned by appropriate manipulation of the nuts The plate openings l0 through which the bolts 9 pass are normal to the spherically curved surface l2 and, as shown in Fig. 2, are arranged in groups of fourwith the component openings of each group symmetrically arranged about one of a series of further openings |5 formed in said plate. The openings l5 are provided to receive therethrough a series of anchor bolts l6 which extend in direction radially of the splay point of the cable. The anchor bolts are assembled with the plate as shown in Fig. 1 where it will be noted that these bolts pass through the openings l5 into threaded engagement with suitable internally threaded collars welded to the flat face of plate 5 in line with openings I5. In addition to passing through the plate 5 the anchor bolts l6 pass through a suitable arrangement of openings l8 and. I9 provided in front and rear spacer plates 20 and 2| which are connected to each other by suitable frame members 22 to form the frame structure generally indicated at 23. The frame structure 23 is designed and installed so that the rear plate 2| is supported in a vertical position on masonry foundation 24 while the front plate is supported in a vertically inclined position on a portion 24a of the foundation which is at a higher elevation than that on'which the rear plate 2| is supported. In this connection it will be noted that the two plates 20 and 2| are connected by the framing members 22 so that the plate 20 is'positioned withits upper and lower edges at a higher level than the corresponding edges of the plate 2| and with its lower edge spaced a greater distance from plate 2| than its upper edge. The openings l8 and IQ of plates 20 and 2| are arranged in circles of sufiicient diameter predetermined to take care of the divergence of the rods l6 which pass through openings in the anchor plate 5 and extend in directions radially of the splay point of the cable. The anchor plate .5 is preferably maintained in spaced relation to the front plate of frame 23 by a series of tubular members 25 surrounding portions of the rods l6, one end of each tubular member being welded to the plate 20 and the other end to the spherically curved surface l2 of plate 5. not shown in the present drawings it will be understood that the anchor rods l6 and the frame 22, after being installed as shown in 'Fig. 1, are embedded in a mass of concrete forming part of a pier or other masonry structure to which the loads on the cable strands 6 are to be transferred.

Figs. 7 to 10 inclusive illustrate a modification in which single plate 5 is replaced by a plurality of plate sections 26 designed to serve the same purpose. These plate sections are clamped in place between the opposing grooved portions 28 of a series of anchor plates 29 held together by suitable clamping bolts 30. The surfaces of plate sections 26 which are engaged by the nuts II are spherically curved, as indicated at 26a, about a common center coinciding with the splay point of the cable with the result that the anchorage points of the cable strands arespheroidally disposed about the splay point of the cable in the same manner as described in connection with Figs. 1 to 6 inclusive.

A feature common to both of the installations described herein is that the cable strands are anchored at points spheroidally disposed about the splay point of the cable so as to be equi-distant therefrom. This is provided for, in Figs. 1 to 6 inclusive, by the spherically curved surface I 2 of the one-piece anchor plate 5 to which the cable strands are anchored by the nuts II. The same result is obtained in Figs. 7 to 10 inclusive by providing the anchor-plate sections with the spherically curved surfaces 26a for engagement with the strand anchoring nuts II.

To avoid bending of the strands or strand connections it is important, in connection with the construction illustrated in Figs. 1 to 6 inclusive, that the openings l0 and I5 through which the bolts 9 and I5 pass be normal to the curved surface [2 of plate 5. The grouping of the bolt receiving openings l0 so that the component openings of each group are symmetrically disposed about one of the bolt receiving openings I5 is also important since it facilitates uniform transmission of loads to the masonry along lines parallel with the direction of pull on the strands.

Having thus described my invention, what I claim is:

1. Means for anchoring the strands of a multiple strand cable comprising a single anchor plate to which all of the strands are adjustably connected and anchor rods through which the strand loads imposed on theanchor plate are transferred direct to. masonry concentric with the pull on said strands.

2. Means for anchoring the individual strands of a multiple strand cable comprising a single anchor plate having one side spherically curved about a center coinciding with the splay point of the cable and means for adjustably anchoring While the cable strands to the curved side of the plate.

3. Means for anchoring the individual strands of a multiple strand cable comprising an anchor plate having one side spherically curved about a center coinciding with the splay point of the cable and means for adjustably anchoring each strand to such curved side of the anchor plate so that the points of anchorage thus established are spheroidally disposed about the splay point of the cable and are equi-distant therefrom, said last mentioned means being adjustable to permit selective tensioning of the strands.

4. Means for anchoring the strands of a multiple strand cable comprising a single anchor plate to which all of the strands are adjustably connected by fittings permitting selective tensionin of the strands, and a series of anchor bolts connected to the anchor plate for transmitting the pull of the strands from the anchor plate direct to masonry in which the anchor rods are embedded.

5. Means for anchoring the strands of a multiple strand cable as set forth in claim 4 in which said fittings are connected to the anchor plate in groups so that the component fittings of each group are symmetrically arranged about one of the anchor rods.

6. Means for anchoring the individual strands of a multiple strand cable comprising a single anchor plate, a'series of bolts passing through spaced openings formed in said plate, one end of each bolt being attached to a socket member fixed to one of the cable strands and the opposite end being fitted with a nut bearing against the side of the plate remote from the said socket member, the last mentioned side of the plate being spherically curved about a center coinciding with the splay point of the cable.

7. Means for anchoring the strands of a multiple strand cable as set forth in claim 6 in which the openings through which said bolts pass are normal to the spherically curved surface of the plate. V

8. Means for anchoring the individual strands of a'multiple strand cable comprising a single anchor plate having one side spherically curved about a center coinciding with the splay point of the cable, a series of bolts passing through spaced openings formed in said plate, each bolt having one end fitted with'a nut bearing against the spherically curved side of the plate and the other end attached to a socket member fixed to one of the cable strands at the opposite side of the plate, a plurality of anchor bolts passing through further openings formed in said plate and secured thereto and a frame structure provided with bolt receiving openings through which the anchor bolts extend, said frame structure being located at the curved side of said plate, said frame structure and anchor bolts being adapted to be embedded in masonry to resist the pull of the cable strands on said plate.

9. Means for anchoring individual strands of a multiple strand cable comprising a plurality of anchor rods, a frame in which said rods are held in predetermined spaced angular relation so that said rods extend in directions radially of the splay point of the cable, said frame and rods being adapted to be embedded in a concrete or masonry structure to which the loads on the cable strands are to-be transferred, and means securing the cable strands to the cable endsof said rods so that the strands are anchored at points spheroidally disposed about the splay point of the cable.

10. Means for anchoring individual strands of a multiple strand cable comprising a plurality of anchor rods, a spacing frame in which the rods are held in predetermined angular spaced relation so that the rods extend in directions radially of the splay point of the cable, said frame and rods being adapted to be embedded in a concrete or masonry structure to which the loads on the cable strands are to be transferred, and adjustable connections through which the cable strands are connected to the cable ends of the anchor rods so that the strands are anchored at points spheroidally disposed about the splay point of the cable.

11. Means for anchoring individual strands of a multiple strand cable comprising a plurality of anchor rods embedded in a concrete or masonry structure to which the loads on the cable strands are to be transferred, said rods being arranged in predetermined spaced angular relation to extend in directions radially of the splay point of the cable and means connecting the cable strands to the cable ends of said rods to anchor the strands at points spheroidally disposed about the splay point of the cable, the arrangement being such that bending of the cables at their points of anchorage is substantially avoided.

FREDERICK J. Mcl-IUGH.