US 3570848 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
March 16, 1971 n. c. BOWEN 3,570,848
TIGHTWIRE Filed Sept. 16, 1969 s Sheets-Sheet 1 94 F/ G 3 INVEN'IUR.
March 16, 1971 c. BOWEN TIGHTWIRE Filed Sept. 16, 1969 3 Sheets-Sheet 2 v WW nh. '30 ml 33 INVENTOR.
March 16, 1971 c, BOWEN 3,570,848
TIGHTWIRE Filed Sept. 16, 1969 3 sheetspsheet 5 11M! l-m-mll m F/ /4v INVENTUR.
United States Patent 3,570,848 TIGHTWIRE Duane C. Bowen, Wichita, Kans. (2541 State St., Carlsbad, Calif. 92008) Filed Sept. 16, 1969, Ser. No. 861,544 Int. Cl. A63b 23/04 U.S. Cl. 272-60 19 Claims ABSTRACT OF THE DISCLOSURE Tightwire sports equipment includes standards, between which a cable is tensed, each having a foot portion compr-essively engaging the ground and a second portion in tension secured to the ground against an upsetting moment about the foot portion from tension. Alternatively or additionally a standard portion in the ground has 'a broader spade portion to resist working in the ground under cable tension. A platform is optionally provided of triangular or annular plan view.
CROSS-REFERENCES Cross-referenced patent applications by the same inventor and under the same titles are:
(a) S.N. 749,336, filed Aug. 1, 1968 (b) S.N. D. 13,751, filed Sept. 27, 1968, now abandoned (c) S.N. 839,179, filed July 7, 1969 BRIEF SUMMARY OF THE INVENTION AND OBJECTIVES My invention relates to sports tightwire equipment in general and relates particularly to standard construction (especially in the vertical plane of the tightwire) which include an inner foot portion in compression and an outer securing portion in tension, with or without ground penetrating spade standard portions to limit working in the ground, and with or without annular or triangular platforms.
Tightwire sports equipment desirably has a number of characteristics:
(a) acceptance of heavy tension loads ('b) economical construction particularly for individual family purchases as differentiated from institutional purchases (c) limiting loosening of standard apparatus in the ground during use, in various type of soils, under different moisture conditions, and for varying lengths of time and rigorousness of usages (d) adaptation to use inside buildings (game rooms,
(e) avoidance of needlessly exposed surfaces that a user could strike in falling from the wire (f) displacement of tightwire tightening means from the area of the tightwire cable to be walked upon (g) providing other desirable features in-so-far as they are consistent with cost objectives It is an objective of my invention to best select among or combine the above factors in tightwire sports equipment design.
My invention will be understood, together with additional objectives and advantages thereof, from the following description, read with reference to the drawings, in which:
FIG. 1 is a perspective view of a specific embodiment of my invention.
FIG. 2 is an elevational view taken on line 22 of FIG. 1.
FIG. 3 is a side view of one of the standards viewed in FIG. 1.
FIG. 4 is a fragmentary, enlarged view, partly in section, taken on line 44 of FIG. 1.
FIG. 5 is a fragmentary, enlarged perspective view, partly in section, of a lug portion of a standard.
FIG. 7 is an enlarged top view of a portion of one of the standards viewed in FIG. 6.
FIG. 8 is an enlarged, fragmentary view, partly in section, taken on line 8--8 of FIG. 7.
FIG. 9 is an enlarged, fragmentary view, partly in sec tion, of portions of the foot and stake members of one of the standards viewed in FIG. 6.
FIG. 10 is a perspective view of a further modified form of the invention.
FIG. 11 is an enlarged, fragmentary view, partly in section, of the cable securing portion of one of the standards shown in FIG. 10, except that a J-bolt is used instead of a U-bolt.
FIG. 12 is a perspective view of further modifications of standards, the two standards viewed being identical except for an inner foot extension on the standard viewed on the right.
FIG. 13 is a top view of the standard viewed on the left in FIG. 12.
FIG. 14 is an enlarged, fragmentary view, partly in section, of the cable tensing assembly in FIG. 12.
In the specification and claims the expression cable is used in referring to the tightwire 10 and is hereby defined as not only covering cable but also equivalent tension members. Usually a cable or metal wire rope will be used for this purpose today although probably in the past before wire rope was much available other tension members were used such as single strand wire or hemp rope. The preferred end securing method for cable 10 are loops 12 formed by cable clamps 14, although other securing means could be substituted. Tension is applied to cable 10 alternatively by a turnbuckle 16 (FIGS. 1-5 construction), an eye-bolt 18 (FIGS. 6-9 and 12-14 construction), a J-bolt 20 (FIG. 11) or a U-bolt 22 (FIG. 10). The same reference character 24 is used for the nuts on these various bolts. Because of twisting of cable 10 during use it is necessary to provide secure locking of nuts 24, which can be provided by double nuts, by lock nuts, or even by wiring or cotter pinning to secure the nuts.
While on the subject of tensing the cable, the special provisions of the FIGS. 6-9 and 12-14- constructions will be reviewed. Note in the FIGS. 10-11 constructions that the U-bolt 22 or J-bolt 20 respectively plus cable loop 12 and cable clamp 14 are between the standards in position to be stepped on by the user in mounting the tightwire. FIGS. 10-11 are stripped down models of minimum price, and also do not have platforms, and the inconvenience of having tensing and securing means underfoot is traded off for price reduction. However, a price increase to get these members out from under foot will frequently be acceptable, and the constructions of FIGS. 6-9 and 12-14 have similar structures to achieve this end. Incidentally, the securing means of FIGS. 6-9 and 12-14 could be used on the FIG. 10-11 construction and vice-versa.
Turning next to FIGS. 7 and 8, a housing 30 is shown which is square in cross section and has an open end 32 freely abutting the standard (not being welded or otherwise secured to the same) and has an outer end 34 closed (by a welded-in plate) except for an opening 36 to pass eye bolt 18. The upright standard has an opening 40 to pass cable 10. A slot 42 in housing 30 can be used to pass any excess cable length 44. It will be understood that this tensing assembly puts all of the hardware outside of the standards so as to leave the cable 10 between the standards free for walking. An eye-bolt '18 is preferred for this assembly because it is symmetrical to fit in housing 30, although a J-bolt or other threaded tension member may be accommodated by this design or by change of housing cross-section. FIG. 14 is a similar construction except that a tubular housing is used, the inner open end 52 is configured to abut a tubular standard, and the other end is closed simply by a washer 54 (the washer 54, housing 50, and the upright standard merely being held together by the tension applied to cable 10 and not being otherwise secured together). A slot 56 accommodates extra length of cable end 58 if the cable end is not cut off so it can be accommodated within housing 50.
In the various forms of the invention, an upright standard portion 60 (FIG. 1), 62 (FIG. 6), 64 (FIG. 10) or 66 (FIG. 12) is provided to which cable 10 is connected and between which cable 10 is tensed. In FIG. 1, upright 60 is an angle iron, in FIG. 6 upright 62 is a channel, in FIG. 10 upright 64 is a channel, and in FIG. 12 upright 66 is tubular. In FIGS. 6, 10, and 12 the upright extends above cable 10 at 68 far enough to be grasped by the hand of a user, standing on the wire, before departing from the standard or returning to the same. In FIG. 1 this function is accomplished by a pair of separate uprights 70 (formed from angle iron) between which cable 10 passes.
In the FIG. 1, FIG. 6 and FIG. 12 constructions a foot portion 72, 74, 76 respectively is provided which extends from upright portions 60, 62, 66 respectively to a location on the ground spaced from the upright portions in a direction parallel to cable 10. In FIGS. 1 and 6, foot portions 72 and 74 compressively engage the ground, whereas in FIG. 12 foot portion 76 is in an opposite sense, e.g., the foot portion 76 is held against raising by tension means including ground anchors 78 having eyes 80 which are connected to foot members (tubes) 76 by adjustable metal straps 82. Straps 82 are sometimes called hose or pipe clamps and include a slotted band and a screw member engaging the slots to tighten the same. The ground anchors 78 depicted are rod shaped members with helical blades on their lower ends. Note that the standard viewed on the right in FIG. 12 has an inward tubular extension 84 which can be thought of as a compression foot member in the same sense as the foot members in FIGS. 1 and 6.
In FIGS. 1, 6, and 12, all forms have a first inner standard portion which is closer to the other standard compressively engaging the ground and a second outer standard portion which is farther from the other standard portion which has securing means securing the same to the ground whereby the upright portions (60, 62, and 66 respectively) are held upright against cable tension by compression of the first portion relative to the ground and by tension of the securing means against an upsetting moment on the standards from tension of cable 10. In FIG. 1 the foot 72 is the first inner portion compressively engaging the ground, in FIG. 6 the foot 74 is the first inner portion compressively engaging the ground, and in FIG. 12 upright 66 is the first inner portion engaging the ground in this case by ground penetration at (supplemented on the right side in FIG. 12 by compressive foot extension 84). In FIG. 12, the second outer standard portion secured to the ground is foot 76 and the securing means is ground anchor 78. In FIG. 6 the second outer standard portion secured to the ground is upright 62 which is secured to the ground by ground penetration at 92. The efiectiveness of portion 92 to adequately secure the tightwire will depend on the type of soil, depth of penetration, moisture conditions, and length and type of usage (i.e., this version could be taken along on a picnic or outing and could be readily set temporarily in the ground, so that the unit would not have long to work in the ground to loosen the portion 92). Some types of soil will hold portion 92 more securely than others. A clay, for example, will hold the portion 92 better in the absence of rain or excess moisture. In FIG. 1, the second outer standard portion is upright 60 which has securing means to the ground in the form of ground anchors 94, having eyes 96, attached to a flange or lug 98 on upright 4 60 by a J-bolt having a hook 102 engaged in eye 96 and extending through an opening 104 in lug 98 and secured by a lock nut 106.
In FIG. 6, a broader ground bearing pad increases the compressive area of foot 74 on the ground. A stake 112 extending through an opening 114 in foot 74 may be used to hold foot 74 from swinging around as there is not much to hold foot 74 in the vertical plane of cable 10 otherwise. By having foot 74 in FIG. 6 (and foot 84 on the right hand side in FIG. 12) under cable 10 in the same vertical plane, a user falling from the wire will have little chance of hitting the foot structure. Portion 92 in FIG. 6, upright 64 in FIG. 10, and portion 90 in FIG. 12 have, in addition to other functions in supporting the tightwire, the function of avoiding sidewise tilting of the standards. As this lateral movement is at right angles to the vertical plane of tension in cable 10, there are relatively small forces to resist sidewise, so that mere postlike penetration will sutfice to resist sidewise movement. In FIG. 1 the sidewise forces and force components are accepted by the spacing of the lower ends of upright 70 laterally to the sides of the vertical plane of tightwire 10. The various usages of channels and angles and their dis positions to maximize strength in needed directions will be obvious, as will the various braces 120. Turnbuckle 16 in FIGS. 2, 3 and 4 is hooked into an opening 122 in a flange or lug 124 welded in angle iron upright 60.
In FIG. 12, an annular platform for users to stand upon is provided on each upright 66 which is received in an annular flange 132 and secured by a set screw 134. It will be understood that annular platforms can be provided in FIGS. 6 and 10 by changing the opening in the annulus to receive a channel shaped standard. A triangular platform is provided in FIG. 1. The thickness will depend on the material, i.e., wood versus metal. A triangular supporting frame is provided by angle irons 142. Like angle irons 144 rest on the ground.
The ground penetrating portions 90 (FIG. 12) and 92 (FIG. 6) have spades to broaden their effective areas laterally of the vertical plane of tension in cable 10, and it will be understood spades 150 act to limit the tendency of the standards to work in the ground during use of the tightwire.
This spade concept is carried further in FIG. 10 in which the upright channel shaped standard 64 and a broad spade welded or otherwise secured to standard 64 are depended upon to accept the tension of cable 10. The spade 160 extends above the ground to the area of attachment of cable 10 for strength purposes and it will be observed that standard channel 64 and spade 160 have a T relationship to resist bending (a channel was used instead of a T for member 64 because of the need to pass bolt 20 through the center of the shape). The adequacy of spade 160 to secure upright 64 against tilting in the vertical plane of tightwire 10 will depend on about the same factors as involved with upright standard portion 92 in FIG. 6, i.e., soil conditions (or even the use of some concrete, although this is to be avoided generally in standard construction to minimize expense, time, and effort of erection), moisture, conditions, whether the standard erection is temporary or more or less permanent, the weight of people using the wire and the vigor of their activity, etc. Of course, a principal advantage of the FIG. 10 construction is economy, and secondarily the advantage is simplicity of erection.
Note that the FIG. 1 construction is particularly adaptable to use inside, such as in a gymnassium, because it may be secured to a floor with only one fastener at each end. Usually in that case bolt means or an expansion shield or socket or the like will be used to secure into a floor instead of a ground anchor 94, although if a concrete fioor were thin enough it would be possible to go through the concrete and set a ground anchor in the underlying earth. When the claims or specification speak of the ground, this term is defined as including the floor in the case of indoor usage.
It will be also understood that the FIG. 1 construction has the desirable features, for inside or outside use, of a platform, of shielding the cable tensing means (turnbuckle 16) by the platform, and of a pair of uprights 70 to be grasped by the user in leaving or returning to the platform. The structure accepting tension includes upright 60, the securing means of the same including ground anchor 94, and the foot portions 72. A disadvantage of the FIG. 1 construction is greater cost than some other forms of the invention.
FIG. 6 avoids the cost of a ground anchor or a platform and is otherwise considerably stripped down. The acceptance of cable tension depends on the combination of a foot 74 which the standard must upset over and the ground penetration 92 of the upright standard (together with spade 150). The limitations in standard security without a ground anchor in connection with FIGS. 6 and 10 construction have already been noted. Compared with the FIG. 10 construction, the tensing assembly in FIG. 6 including housing 30 is disposed out of the way on the outboard side of the standard.
The FIG. 10 construction is of about minimum structure and cost. Acceptance of tension in cable 10 depends primarily on the breadth and length of spade surface 160 because it is commonly known that steel-postlike body such as channel 64 will not accept high tension and fluctuating loads in most soil conditions. Even with spade surface 160, the FIG. 10 construction will only be suitable in certain soil conditions, unless the standards are merely being set in the ground temporarily during an outing or at least unless the user is prepared to reset the standards periodically. A clay soil or the like and minimum moisture would provide the best soil conditions to accept high fluctuating loads over a longer period of time.
FIG. 12. on the left side may be thought of as reversing the FIG. 6 relationships by having the braced triangular structure 76 to the outside rather than to the inside, whereas FIG. 12 on the right side shows that these are not mutually exclusive alternatives by having foot-like braced triangular structures 76, 84 both outwardly and inwardly directed in the vertical plane of the tightwire. Although the FIG. 12 and FIG. 6 structures are illustrated as being structurally somewhat different (and the former is made of structural shaped metal), it will be observed one model could sufiice with the disposition of the foot structure (inward or outward) being up to the users choice, a ground anchor 78 and strap clamp 82 being needed if the FIG. 12 (left) foot disposition is used.
The referenced prior patent application have fully developed the subject of the disposition of cable 10 a short distance above the ground and I will not review that matter other than to say that about eighteen inches (at the ends) is about optimum with children but the main point is that the cable is not at the heights professional wire walkers use, which is the difference between a relatively safe amateur sports-play activity and a relatively hazardous professional entertainment activity.
Having thus described my invention, I do not wish to be understood as limiting myself to the exact details of disclosure but instead I want to cover those modifications of my invention which will occur to those skilled in the art after learning of my disclosure and which are properly within the scope of my invention.
1. Tightwire sports equipment including, in combination, a cable supported a short distance above the ground and intension between a pair of standard, said standards comprising:
(a) each standard including an upright standard portion and a foot standard portion, said cable connected to said upright portion and supported there by a short distance above the ground and said foot portion extending to a location on the ground spaced from said upright portions in a direction parallel to said cable;
(b) each standard including, a first standard portion which is closer to the other standard compressively engaging the ground, and a second standard portion which is on the opposite side of said standard from the other standard having securing means secured in the ground, whereby said upright portion is held upright against said cable tension by compression of said first standard portion relative to the ground and by tension in said securing means against an upsetting moment on the standards from said cable tension.
2. The subject matter of claim 1 in which said upright standard portion penetrates the ground.
3. The subject matter of claim 2 in which the end of said upright standard portion penetrating the ground has a spade secured thereto which is broader than said upright standard portion in a direction lateral of said cable thereby to resist movement thereof in the ground in the vertical plane of said cable.
4. The subject matter of claim 1 in which the second of said standard portions is said upright standard portion.
5. The subject matter of claim 4 in which said securing means is penetration of said upright standard portion in the ground.
6. The subject matter of claim 5 in which said upright standard portion is a single pole-like member and said upright standard portion and said foot standard portion are in the vertical plane of said cable, in which said foot portion is formed by a horizontal member and a member diagonal to vertical and horizontal forming with said upright standard portion a right angular triangle when viewed from the side, in which there is a stake into the ground attached to said foot standard portion to prevent it swinging out of said vertical plane, and in which there is a plate at the end of said foot portion forming a ground bearing pad for bearing upon the ground.
7. The subject matter of claim 1 in which said upright standard portion is a single pole-like member and in which a platform is formed about at the level of said cable by an annular member around said pole-like member and secured to the same and supported thereby.
8. The subject matter of claim 1 in which the first of said standard portions is said upright standard portion.
9. The subject matter of claim 8 in which said securing means is a ground anchor secured to said foot standard portion.
10. The subject matter of claim 9 in which said up right standard portion is a single pole-like member and said upright standard portion and said foot standard portion are in the vertical plane of said cable, and in which said foot portion is formed by a horizontal member and a member diagonal to vertical and horizontal forming with said upright standard portion a right angular triangle when viewed from the side.
11. The subject matter of claim 1 in which said upright standard portion is a single pole-like member which extends above said cable to a height to be grasped by the hands of a person on said cable.
12. The subject matter of claim 1 in which said cable is secured to each upright standard portion at the height of said tightwire by a bolt secured to said upright standard portion and said cable having a cable loop at each end and said bolt having return-bend means at its inner end to which said cable is attached by one of said cable loops and said bolt having nut means at its outer end portion for tightening said cable.
13. The subject matter of claim 12 in which bolt is a U-bolt and said cable loop is secured to the bend of the U-bolt.
14. The subject matter of claim 12 in which each bolt is a ]-bolt and said cable loop is secured to the hook end of the J-bolt.
15. The subject matter of claim 12 in which each bolt is an eye bolt and said cable loop is secured to the eye of the eye-bolt.
16. The subject matter of claim 1 in which the first of said standard portions is said foot standard portion and includes a pair of vertical pole-like members extending to above the level of said cable Which passes midway therebetween to provide means to be grasped by hand in starting on said tightwire or leaving the same, said upright standard portion and said pole-like members having the relationship of three points of an isosceles triangle when viewed from the top, a substantially triangular, horizontal flat planar member forming a platform at about the level of said cable and the level of the upper end of said upright standard portion, whereby said platform may be used in starting out on said tightwire and in returning.
17. The subject matter of claim 16 in which the lower portions of said upright standard portion and of each pole-like member is connected by a horizontal member substantially on the ground and a member diagonal to the horizontal and vertical extending from an upper point on said upright standard portion to the inner end section of each horizontal member whereby each horizontal member and associated diagonal member and said upright standard portion have the appearance of a right angular triangle when viewed from the side.
18. The subject matter of claim 16 in which said securing means includes a ground anchor and connecting means between said upright standard member and said ground anchor.
19. The subject matter of claim 18 in which said connecting means includes a flange on said upright member overlying said ground anchor, said flange having opening means and said ground anchor having an eye and bolt means between said opening means and said eye.
References Cited UNITED STATES PATENTS 1,419,191 6/1922 Acker 27223 RICHARD C. PINKHAM, Primary Examiner R. DROR, Assistant Examiner