US2387355A - Jetty structure - Google Patents

Description

0d. 23, 19 45. 5 w LD 2,387,355

- JETTY STRUCTURE Filed June 27, 1942 2 Sheets-Sheet l ATTORNEY Oct. 23, 1945. e. w. REHFELD JETTY STRUCTURE fi'iled June 27, 1942 ZShets -Sheet 2 INVENTOR go/ye l Z/ Faye 0. M WM ATTORNEY Patented Oct. 23, 1945 4 UNITED STATES PATENT OFFICE JETTY STRUCTURE George W. Rehfeld; Manhattan, Kans. Application June 27, 1942 Serial No. 448,813

Claims.

This invention relates to ,jetties for controlling banks of streams by retarding erosion and effecta It is well known that jetties of this character aresubjected to bufieting forces tending to their destruction, particularly in times of high water when the current is swift and carries large quantities of driftwood and the like. Consequently it has been the practice to construct such jetties of structural metal members as these members are of permanent character and when rigidlyconnected together and laced provide the desired obstruction and withstand the buifeting effects of driftwood while allowing free passage of the water therethrough. However, structural members are relatively expensive and difiicult to obtain, particularly within an economical distance from the site of the .work. i i i U Therefore, the present invention contemplates the construction of jetties from less expensive and more readily available materials such as concrete, the bulk of which, sand and gravel, is usually obtained at the site of the work, while the cement and reinforcing are available at nearby markets. However, concrete jetties, when made sufliciently strong to withstand the shocks,buifeting and blows from driftage, are too heavy to be self-supporting and sink into the silt so that their effectiveness as an obstruction is relatively short. i

It is, therefore, the purpose of the. present invention to provide a concrete jetty of sufficiently light construction to be self-supporting upon the river. bed and which has the arm members thereof individually formed and flexibly connected to absorb the destructive blows and hammer-like shocks to which they maybe subjected.

Another object of the invention is to provide a jetty with a sufficient number of arms to be effective insupportingthe lacing and provide stable support on the river bed with sufiicient bearing to avoid sinking thereof in quicksands and silt composing a 'river bottom.

structure, the preferred forms of which are illustrated in the accompanying drawings, wherein:

Fig. 1 is a perspective view of a concrete jetty constructed in accordance with the present invention.

Fig. 2 is a section through the jetty taken through those arms that are located with their axes in a common'plane.

Fig. 3 is a detail perspective view of the inner end of one of the arms particularly illustrating the shape thereof whereby the arms when outer end of one of the arms.

Fig. 5 is a perspective view showing the initial step in the assembly of the jetty.

invention, I 'have provided improved details of Fig. 6 is a fragmentary section similar to Fig. 2 showing a modified form of jetty structures.

Fig. '7 is a detail perspective view of the wire connecting member and one of the arms it connects in the form of the jetty illustrated in Fig. 6.

Fig. 8 is a section similar to Fig. 2, taken through a further modified form of jetty.

Fig. 9 is a fragmentary perspective view of adjacent arms of the form of the jetty shown in Fig". 8, the arms being shown in disassembled spaced relation.

Fig. 10 is a perspectiveview of a further modified form of flexible connection.

Referring more in detail to the drawings:

l designates a jetty such as used in controlling the bank of a stream and which has a plurality of individually formed arms 2, 3, 4, 5, 6 and 1 arranged with inner ends thereof grouped together and the outer ends extending radially in the shape of a jack. Each arm is individually formed of concrete, preferably consisting of sand, water and cement, which may be mixed together near the job site to form a plastic mass which is cast in a suitable mold, the molds being shaped to provide relatively narrow, elongated arms having side faces 8-9 and |0H, which may be arranged so that the opposite faces lie in parallel planes or the faces may be tapered from the inner ends I 2 toward the outer ends I3 to increase the strength thereof at the center of the jetty and reduce the weight of the outer ends of the arms correspondingly to the bending forces acting along the length thereof. While I have illustrated the arms as being of. substantially rectangular cross-section, it is obvious that they may be of other cross-sectional shapes.

The corners between the adjacent side faces are preferably bevelled, as at M, from a point spaced from the inner ends thereof to the outer ends to reduce the amount of material therein and yet maintain a high strength to weight ratio. The

inner ends l of the arms converge from the respective faces, as at I6, and terminate in substantially rounded portions 11, as best shown in Fig. 3. The inner ends of the arms are also provided with transversely arranged openings 18 and i9, staggered withlrespect to each other and have sufli cient taper to drain water therefrom and allow for expansion of ice toward the larger end in case of freezing temperatures, the openings being to pass flexible ties 20 whereby the inner ends of the arms are drawntogether to form the cluster, as

, sufficient retardation to flow of water through the jetty: and cause sinking of debris, silt and the like which builds up the surface on'whi'ch the jetty is supported. If desired, intermediate lacing may be provided by equipping the arms with additional shown in Fig. 1. The outer ends of the arms have similar transversely staggered openings 2 t and 22 which extend parallel with grooves 23 and 24 formed in the outer ends of the arms, as best shown in Fig.4, The arms thus. shaped may be provided with reinforcing, for example, ordinary rods. or wire,however, I find that lengths of flexible stranded cab1e 25. disposed longitudinally and substantially coextensive with the axes of thearms are more satisfactory and are preferable. The ends of the cables are. unraveled as shown at 25 and spread apart to betterreinforce the portions of the concrete surrounding the openings !8l9 and 2l22.

In assembling,,thefarms into a. jetty, three of them are'plac'ed to form a tripod, as. shown in Fig. 5', with the grooved or notched ends upon the ground and with the inner ends brought together with the bevelled facesv [5; of one arm resting against the adjacent bevelled faces. of an adjacent arm. The other three arms are then supported in a similar but inverted position with the converging faces, l6 resting upon the corresponding faces'of the previously positioned arms. In this position four of the arms are located with their axes in a common plane and the other two arms. extend I at substantially right angles thereto. When thus positioned the faces l5 of those arms lying in a common plane form' socket-like recesses for. the other arms that extend at right angles thereto whereby the arms are retained in centered relation] but. the rounded surfaces allow for independent pivotal movement of the respective arms under shocks when the jetties are in use as later described. I

Prior to lacing, the arms may be. temporarily supported" in positionjby suitable spacing rods, or by a jig having shape to retain the desired angular relationship; Thei'nner ends of the. arms 2, 3,4 and 5 are tied or laced together by passing a flexible, preferably stranded, cable 21 through the openings I 9. of the respective arms, after which the endsof the cable are-drawn together in lapped relation as shown at 28 in Fig... 2. and. secured by a clamp 29.. A similar cable 30 is then passed through the openings l8 of the. arms 2, 1, 4 and 5 and the ends secured by a similar clamp, suificient tension having been drawn in the respective cables so that the ends of the arms are retained in abutting contact with each other as shown in Figs. '1 and 2.

The outer ends of the arms are then. connected by a lacing cable, for example an end of a cable 3| islaid in the groove 23 of one of the arms and. then extended in reverse direction, through the. opening 2|, after which the cable is again laid. in the groove 23 and extended to the neXt ad-- j'acent arm where the cable is secured in like manner and thence to the next arm, and. so. on until the place of starting, where'the ends are connectopenings such as illustrated at 32.

With the arms constructed and assembled as described, the jetties are relatively light in weight and yet effectively withstand shocks to which they are subjected without breaking of the concrete as the respective ends thereof are flexibly supported and one arm is. freeto move independently'of'the' other arms under, the blow :of a log or'thev like carried in the stream.

"In placing the jetties they are preferably anchored in rows and. the. individual jetties are spaced apart by'cabl'es passingthrough crotches formed between opposite arms" and secured. on the" respective/sides thereof by fastening devices such as clamps, as in conventional jetty anchorage. The free ends of the'cables are anchored'to suitable dead men in the bank of the stream so that. the entire line of jetties is adapted to position itself and thereby further resist shock that might tend to shatter the arms. The jetties when thus; anchored have three of the arms'supported' upon the bed'jofthe stream and the outer ends thereof become imbed'ded', while the other arms extend outwardly and upwardly" to provide the necessary obstruction in effecting a deposit of debris; silt andthe like carried in the water flowing through the jetties.

Attention is directed to the fact that should the arm of a jetty break, the flexible cables forming the reinforcing provide-a 'fiexible anehorage toretain the broken sections together and allow for movement thereof without fracturingthe reinforcement Ye 'll'he'jetty shownin Figs. 6 and 7 is substantially the same as that just d-escribed,'with the exception of the flexible! connection for the inner ends'of'the arms. In this. arrangement the inner endsxof' the. armsare proyidedwith' axial bores. 33 to receive the; ends 3'4 of crossed. rods 3.5.that are'securedtogether at their cross ing: points by welding or the like, as shown in Fig. 7.. In this construction the. arm's'are: assembled by sliding the inner ends thereof. onto the res-pective terminals. 34 of; the. rods. as shown in Fig.1 6. When the lacing is applied, as described in the preferred form, the arms are retained uponthe terminals of the connecting member. but the. connecting member provides sufficient movement of the arms under force of a blow to absorb the shock which would ordinarily be destructive to the; concrete. p

In thev formof theinvention shown in Figs. ,8 and 9, the abutting arms 38-3] and, 38- 39 are related in pairs, that is the flexible reinforcing 40 extends through and forms the reinforcing of, an aligning arm The reinforcing cable 4| of the arm. 42, however, extends through a channellike bore 43- of the. aligning arm 44, the bore starting within the axis of thearm 44 and emergin at a spaced. point. on the side thereof so that after the connecting portion of the cable for the arms 36 and 31 is crossed with that of the arms which are flexibly interconnected by the reinforcing to further enhance flexibility of the jetty.

Fig. shows a connection similar to that illustrated in Fig. 7, however, the pintles 45 are formed of separate pieces 48, 49 and 50, two of which, 48 and 49, are bent at right angles and arranged oppositely to each other so as to pass the third member 50 therebetween. The members, being linked together, provide for greater flexibility than the welded form shown in Fig. '7.

From the foregoing it is obvious that I have provided a light weight jetty construction which is well adapted to be formed of concrete and which is capable of withstanding the shocks to which such jetties are subjected.

What I claim and desire to secure by Letters Patent is:

The portion of the 1. A concrete jetty including, members arranged in converging relation with ends thereof in abutting contact to form a substantially tripod support, arm members having ends movably engaged with the abutting ends of said support and diverging outwardly, means retaining said ends in movable contact, and lacing connecting said members.

2.A concrete jetty including, a plurality of radially extending arm-like members having bores in ends thereof, interconnected rod members having terminals extending into said bores 5. A concrete jetty including, a plurality of radially extending arm-like members having bores in ends thereof, rod members interlinked with each other, a rod member extending through the linked members, said rod members having terminals extending into said bores to retain said arm-like members in assembly, and lacing connecting outer portions of said arm-like members.

6. A concrete jetty including, lower members arranged in converging relation with ends thereof in abutting contact to form a substantially tripod support, upper arm members having ends engaged in abutting contact with the ends of,

the lower members of said support and diverging upwardly and outwardly, and cables connecting the abutting ends of said members to retain the shape of the jetty.

7. A jetty including a plurality of individually formed radially arranged arms extending outwardly from a common central point and upwardly and downwardly therefrom and having their inner ends in actual abutting relationship, means for flexibly connecting the inner abutting ends of the arms and maintaining the same in substantially abutting relationship and providing individual pivotal movement of the arms,

and means for connecting the outer ends of the arms with one another and cooperating with said flexible means to secure the arms in an upright self sustaining structure.

8. A jetty including a plurality of individually formed radially arranged arms extending outwardly from a common central point and upwardly and downwardly therefrom and having their inner ends in actual abutting relationship,

ing arms, flexible reinforcing members in said arms and connecting the arms of said pairs, the

, connected ends of the arms of the respective and connecting the arms of said pairs, the connected ends of the arms of the respective pairs being spaced apart to provide movement therebetween, said pairs being arranged with the connected ends of the arms in contact whereby one arm is adapted to have slight rocking movement relative to the other arms, and lacing connecting said arms to maintain said arms in assembly, at least one of said reinforcing members being loosely threaded through an opening in one of the arms and adapted to be attached to said arm after assembly of the arms in said crossed relation.

said arms having openings in their inner abutting ends, flexible means extending through said openings and connecting the inner abutting ends of the arms together and providing for individual pivotal movement of the arms, and means for connecting the outer ends of the arms with each other and codperating with said flexible means to secure said arms in an upright self sustaining structure.

9. A jetty including a plurality of individually formed radially arranged arms extending upwardly and downwardly from a common central point and having their inner ends in actual abutting relationship, and flexible means having at least two spaced apart connections with the respective arms for connecting the arms together forming an upright self sustaining tetrahedron.

10. A jetty including a plurality of individually formed radially arranged arms extending upwardly and downwardly from a common central point and having their inner ends arranged in actual abutting relationship, the downwardly extending arms providing a substantially tripod support, and flexible means having at least two spaced apart connections with the respective arms for flexibly connecting the arms together forming an upright self sustaining structure and providing for limited independent movement of said arms under shock.

GEORGE W. REHFELD.

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