US3765784A

US3765784A - Sealing member

Info

Publication number: US3765784A
Application number: US00128020A
Authority: US
Inventors: S Watson; T Bowman
Original assignee: Watson Bowman Associates Inc
Current assignee: Watson Bowman Associates Inc
Priority date: 1971-03-25
Filing date: 1971-03-25
Publication date: 1973-10-16
Anticipated expiration: 1990-10-16

Abstract

A resilient sealing member, for use in an expansion joint, comprising serrated or dentate top and bottom walls and opposite side walls forming a hollow strip. An internal reinforcing network is provided in the hollow strip and comprises a plurality of web sections defining spaces therebetween into which the web sections may collapse when the side walls of the strip are pressed toward each other.

Description

United States Patent 1191 Watson et a1.

[ SEALING MEMBER [75] Inventors: Stewart C. Watson, Williamsville;

Thomas C. Bowman, Buffalo, both of N .Y.

[73] Assignee: Watson-Bowman Associates, Inc.,

Buffalo, N.Y.

[22] Filed: Mar. 25, 1971 [21] Appl. No.: 128,020

[451 Oct. 16, 1973 Primary Examiner-Nile C. Byers, Jr. Attorney-Ashlan F. Harlan, Jr.

57 ABSTRACT A resilient sealing member, for use in an expansion joint, comprising serrated or dentate top and bottom [52] US. Cl. 404/64 walls and pp i i e walls f rming a hollow trip. [51] Int. Cl. E01c 11/10 n rn r in r ing ne w rk is provided in the hol- [58] Field of Search 94/18 w ip n omprises a plurality of web sections defining spaces therebetween into which the web sec- [56] Refe n Cit d tions may collapse when the side walls of the strip are UNITED STATES PATENTS pressed toward each other.

3,358,568 12/1967 Brown 94/18 8 Claims, 4 Drawing Figures {Q636 7g 72 j 4 Z79 k f77 77v 5. 7/ 75" 1 M 5 7 67 f 5 PATENIEnum 16 1915 3.765384 INVENTORS. Siewon C Maison f 720 mas CBowmarz BY M W ATTORNE I SEALING MEMBER BACKGROUND OF THE INVENTION This invention relates to seals for use in pavement or building joints, and is particularly concerned with preformed sealing strips or members adapted to be inserted in the grooves of expansion joints in, for example, a bridge deck.

It is necessary that expansion joints be used in pavements and the like to allow for expansion and contraction of a given length and/or width of pavement under varying temperature conditions and thus prevent buckling. Such joints are often grooves formed between adjacent pavement sections but may be spaces left between adjacent sections, or even grooves cut in the exposed surface of a pavement or the like.

In pavements such as roads and bridge decks these joints must be sealed in order to prevent accumulation of unwanted particles such as sand, gravel, and dirt and to prevent the infiltration of water which in cold weather freezes and may cause displacement and/or cracking of the adjacent pavement sections by freezing in the joints. For many years, it had been the practice to fill these grooves with a semi-solid filler or sealant such as asphalt or an elastomer-based caulking compound which would yield to permit expansion of the adjacent pavement sections. Because of the failure of these fillers to properly adhere to the side walls of the adjacent pavement sections, especially during the contraction of such sections, and because of a tendency toward brittleness at low temperatures, these joint fillers have permitted the ingress of water and foreign particles which ultimately damage the joint and the adjacent pavement sections. As a result, to maintain the pavement adequately, such joints have required frequent inspection and the tiller has had to be repaired and/or replaced frequently.

In recent years, preformed compressible and expandible elastomer sealing members or strips of indeterminate length have been gaining acceptance and have gradually replaced the caulk-type fillers such as asphalt. Although these known preformed sealing strips have a relatively longer useful life and provide better sealing than the caulk-type fillers, they too have certain limitations. For example, there is a tendency, especially in bridge expansion joints wherein the seals are subjected to extreme-stresses not only by compressive forces but also by vertical forces resulting from vertical displacement of the adjoining bridge sections, for the top edges of the side walls of the sealing strips to rotate upwardly and away from the facing surfaces of the adjoining sections. Also, in some sealing strips having internal networks of diagonally extending webs, these webs often bulge or fold excessively during compression. After long periods of maximum compression, such as might occur in hot summer months during which the pavement sections are continually expanded, the elastic properties of these webs are adversely affected and the webs tend to take a permanent set so that total recovery is not realized, thereby reducing the useful life of these sealing strips.

SUMMARY OF THE INVENTION In the sealing strip or member of the present invention, as hereinafter described, the above-mentioned deficiencies are obviated by providing specially configurated top and bottom walls and an internal reinforcing network comprised of a series of webs or struts arranged in a symmetrical pattern which prevents rotation of the side wall strip edges away from the adjoining paving sections and raises portions of the top wall of the strip during compression of the strip in use.

Generally speaking, the sealing strip of the present invention comprises a pair of parallel side walls joined together at their tops and bottoms by serrated or dentate top and bottom walls to form an elongated, hollow body. The strip is provided with a symmetrical internal reinforcing network of webs for effecting an equalization of sealing pressure at the strip side walls. These webs define various shaped cavities or spaces therebetween into which the webs are displaced during compression of the sealing strip and are interrelated in such a manner as to prevent rotation of the top and bottom edges of the strip side walls away from the facing surfaces of the adjacent pavement sections. Also, these internal webs cause upward movement of portions of the strip top wall to eject foreign matter accumulated in the joint above the sealing strip.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an end elevational view of a sealing strip constructed in accordance with the present invention and shown in the uncompressed state;

FIG. 2 is a fragmentary top plan view of the sealing strip shown in FIG. 1;

FIG. 3 is a fragmentary sectional view of the joint between two adjacent pavement sections, showing a sealing strip according to this invention between said sections in a compressed state; and

FIG. 4 is a fragmentary, enlarged, end elevational view of the sealing strip of FIG. 1, illustrating some of the internal forces-resulting from compression of the sealing strip.

DETAILED DESCRIPTION OF. A PREFERRED EMBODIMENT Referring to FIG. 1 of the drawings, it will be seen that a preferred embodiment of this invention comprises an elongated sealing strip, comprehensively designated 10, comprising a serrated or dentate top wall 11, a serrated or dentate bottom wall 12, and a pair of substantially parallel, vertical, essentially flat side walls 13 and 14 connected at their upper and lower edges to the top wall 11 and the bottom wall 12, respectively. The sealing strip 10 is conveniently formed of a suitable elastomeric material by extrusion molding. A neoprene composition that retains flexibility and resilience over a wide temperature range is usually prefered. It will 'be understood that the sealing member 10 may vary in length, as desired, and that such members may be of various widths so long as the height of the member varies proportionately to maintain a height to width ratio similar to that shown in FIG. I. i

The top wall 1 1 comprises a pair of

outer sloping portions

15 and 16 extending inwardly and downwardly from the side walls 13 and 14, respectively, and forming therewith a pair of upper rounded corners l8 and 19 projecting above the main portion or body of sealing strip 10. A pair of intermediate sloping portions 20 and 21 extend inwardly and upwardly, respectively, from the lower ends of sloping portions 15. and 16, thereby forming

grooves

22 and 23. A pair of inner sloping

portions

25 and 26 extend inwardly and downwardly from the upper ends of the portions 20 and 21 forming

apices

27 and 28 therewith. The inner sloping portions and 26 converge to form a groove 30. In the uncompressed state of the sealing strip 10, as shown in FIG. 1, it will be seen that the

apices

27 and 28 are disposed somewhat below

rounded corners

18 and 19. It should be noted that the terms top, bottom, up, down, right, left and similar terms of position or direction as used herein refer to the illustration in FIG. 1, but they are used only for convenience of description and should not be construed as limiting the scope of the present invention or as implying a necessary positioning of the structure or portions thereof.

The bottom wall 12 is substantially a mirror image of the top wall 11 and comprises

outer sloping portions

31 and 32 that extend inwardly and upwardly from the side walls 13 and 14, respectively, and form therewith a pair of lower

rounded corners

33 and 34 that project below the body of the sealing strip 10. Intermediate sloping portions 36 and 37 extend inwardly and downwardly from the upper ends of the

portions

31 and 32 forming

grooves

38 and 39 therewith. A pair of inner sloping

portions

41 and 42 extend inwardly and upwardly from the lower ends of sloping portions 36 and 37 and form apices 43 and 44 therewith. The

portions

41 and 42 converge to form a groove 45. The top, bottom, and side walls form an elongated tubular strip provided with an internal reinforcing network of webs or struts as will presently be described.

Extending vertically downwardly from the

grooves

22, 23 and 30, respectively, are a series of spaced, short,

upper web sections

47, 48 and 49, which are substantially parallel with each other and with side walls 13 and 14 and are in general vertical alignment with a series of spaced, parallel, short,

lower web sections

50, 51, and 52, respectively, that extend vertically upwardly from the

grooves

38, 39 and 45, respectively, in the bottom wall 12. Disposed between the upper and lower web sections 47 to 52, inclusive, in a side by side relation between the side walls 13 and 14 are three elongated cells extending longitudinally of the sealing strip and generally diamond shaped in cross section. These cells are bounded by inclined web sections as hereinafter explained.

The diamond shaped cell 53 on the right is bounded in part by a pair of

inclined web sections

54 and 55 extending downwardly and outwardly from the lower end of the upper vertical web 47 and terminating, respectively, in the side wall 13 at approximately the middle thereof, and at an intersection S6. A pair of

inclined web sections

57 and 58 extend upwardly and outwardly from the upper end of the lower vertical web section 50 and terminate, respectively, in the side wall 13 at approximately the midpoint thereof but below the web section 54, and at the intersection 56 to complete the cell 53.

The second, center, diamond shaped cell 59 is bounded in part by a pair of

inclined web sections

60 and 61 extending downardly and outwardly from the lower end of upper vertical web section 48 and terminating at the intersection 56 and an intersection 62, respectively, the latter intersection being laterally spaced from the intersection 56. A pair of

inclined web sections

63 and 64 extend upwardly and outwardly from the upper end of lower, vertical web section 51 and join the

web sections

60 and 61 at intersections 56 and 62, respectively, to complete the center cell 59.

The third, left-hand, diamond shaped cell 65 is bounded in part by a pair of

inclined web sections

66 and 67 extending downwardly and outwardly from the lower end of the upper vertical web section 49 and terminating, respectively, at the intersection 62 and in the side wall 14 at approximately the midpoint thereof. Completing the third cell 65 are a pair of

inclined web sections

68 and 69 extending upwardly and outwardly from the upper end of the lower vertical web section 52, the web 68 joining the web section 66 at the intersection 62 and the web 69 joining the side wall 14 at approximately the midpoint thereof.

Additional elongated hollow spaces or cells extending throughout the length of the strip 10 are formed by the top, bottom, and side walls of the sealing strip 10, together with the reinforcing network of web sections.

Cells

71, 72, 73 and 74, generally trapezoidal in cross section, are formed at the four corners of the sealing strip 10. A pair of side by

side cells

76 and 77, hexagonal in cross section, are provided in the upper central portion of the sealing strip 10 between the upper portions of the center diamond cross sectional cell 59 and

cells

53 and 65, respectively. A pair of similarly shaped

cells

79 and 80 are disposed in the lower central portion of the strip 10 between the lower portion of the cell 59 and the lower portions of the

cells

53 and 65, respectively.

The sealing strip 10 is symmetrical about a horizontal plane XX cut through the longitudinal axis of the sealing strip 10 and a vertical plane YY cut through such axis. This symmetrical design is important in equalizing the sealing pressure acting on the side walls 13 and 14. The intersections 56 and 62 act as pivot points about which the web sections on the right and left side of the plane YY tend to pivot, respectively.

FIG..l illustrates the sealing strip 10 in its normal, uncompressed state prior to the intersection thereof in the slot or groove of an expansion joint. As shown in FIG. 3, the strip 10, in use, may be inserted in the slot 86 between adjacent pavement slabs 87 and 88 such as are used in bridge decks. In many cases the adjacent corners of the slabs are reinforced, as shown, by angle bars 90 embedded therein. Each angle bar 90 comprises a horizontal leg 91 disposed in the plane of the upper surface of the pavement slab and a vertical leg 92 extending downwardly into the slot 86. The lower ends of the legs 92 are provided with inwardly projecting horizontal flanges 93 for support of the sealing strip 10.

Th sealing strip 10 is of such width that it must be initially compressed, usually to about 80 percent of its uncompressed width, to insert it between the opposite vertical legs 92 of the angle bars 90. Prior to inserting the sealing strip 10 into the groove 86, a coating of a suitable lubricant-adhesive is either applied to the exposed faces of legs 92 of the angle bars 90 and/or to the side walls of the sealing strip 10 to facilitate the insertion thereof in the groove and, when set, to cement the sealing strip 10 in place. Suitable lubricant-adhesives are well known and readily obtainable.

FIG. 3 illustrates the sealing strip 10 under substantial compression. As the sealing strip'10 is compressed from a slightly compressed condition to the condition shown in FIG. 3, the upper sloping

portions

15, 16, 20, 21, 25 and 26 fold toward each other raising the apices 27'and 28 to dispel or eject large foreign bodies from the groove 86 above the sealing strip 10. The

apices

27 and 28 reach a height approximating the level of the rounded corners l8 and 19. Note, however, that the whole top wall 11 of the sealing member is always maintained below the level of the upper surfaces of the adjacent pavement slabs 87 and 88. Compression of the strip also brings about corresponding outward movement of the lower apices 43 and 44.

Referring to FIG. 4, which illustrates a portion of the right side of the sealing strip 10 in uncompressed state, it will be seen that as the strip is compressed laterally, the

web sections

54 and 57, respectively, exert force, indicated by arrows A, against the web section 55 at its juncture with web section 47 and against web section 58 at its juncture with web section 50 This causes pivoting of the

web sections

55 and 58 about the intersection 56, thus tending to straighten them out into alignment with each other and with

web sections

47 and 50, thereby preventing buckling of the webs and giving a controlled collapse of the sealing strip 10.

Furthermore, compressibility of the sealing strip 10 or collapsibility of the internal reinforcing web network into the spaces provided therein is better controlled because buckling of the web sections is eliminated. Also, due to the angular orientation of the

web sections

54 and 57 relative to the side wall 13, the moment forces are equally distributed so as to prevent rotation of the side wall away from the interfacial surface of the adjoining angle bar leg 92 during compression and/or when a vertical force is exerted on the side wall 13 due to vertical displacement of the adjacent pavement sections. The forces exerted on the right side of the sealing strip 10, as shown in FIG. 4, are also applied to the left side thereof maintaining equal pressurization of both sides of the sealing strip 10.

The vertical plane of symmetry (YY) of the sealing strip 10 insures equal sealing pressure along both side walls 13 and 14. It should also be noted that the sealing member 10 is reversible due to its horizontal plane of symmetry (XX). An advantage residing in this feature is that the strip 10 may be inverted, if desired, in the event of damage to the top wall 11 during handling and installation of the sealing strip 10.

The present invention thus provides a new and improved sealing member for pavement joints having corrugated or dentate top and bottom walls and a novel, integral, reinforcing network of internal webs or struts which is symmetrical in two planes and which provides equal sealing pressure along both side walls of the sealing strip. The configuration of this web network prevents buckling and overbending of the web sections and also causes the elevation of portions of the top wall to eject foreign matter from the joint above the sealing strip.

A preferred form of this invention having been herein described and illustrated in the drawings, it is to be understood that variations and modifications thereof can be made without departing from the spirit and scope of this invention, as defined in the appended claims.

We claim:

1. A seal for expansion joints comprising an elongated hollow strip having opposite side walls; a top wall and a bottom wall, the junctures of said side walls with said top wall and said bottom wall being rounded; and an integral, internal, reinforcing network of web sections, said network comprising a plurality of laterally spaced, upper web sections extending vertically downwardly from said top wall in generally parallel relation with said side walls, a plurality of laterally spaced, lower web sections extending vertically upwardly from said bottom wall in generally parallel relation with said side walls and substantial vertical alignment with said upper web sections, a plurality of generally diamond shaped cells including a centrally located cell disposed in a side by side relation between said side walls, each of said diamond shaped cells being bounded solely by a plurality of other web sections connected at their upper and lower ends, respectively, to one of said upper and one of said lower web sections, said central cell in cross-section being smaller than the others of said diamond shaped cells and symmetrical about a vertical axis, said strip being resilient and flexible and adapted, when subjected to pressure against said side walls, to be compressed whereby to narrow the width of said central cell and tend to straighten the web sections by which said central cell is bounded to provide increased support for the top and bottom walls of said strip.

2. A seal as defined in claim 1 wherein each of said diamond shaped cells is bounded solely by a pair of inclined web sections extending downwardly and outwardly from the lower end of one of said upper web sections and a pair of inclined web sections extending upwardly and outwardly from the upper end of the one of said lower web sections vertically aligned with said one upper web section, and joining the lower ends of said first pair of inclined web sections.

3. A seal as defined in claim 1 which comprises three generally diamond shaped cells, each cell being quadrilateral in cross section, one of said cells being disposed between the other two cells and joined thereto at laterally spaced intersections in said network.

4. A seal as defined in claim 1 wherein said top wall is serrated and comprises a plurality of transverse sloping portions, said sloping portions extending inwardly from said side walls and at their junctures defining grooves and apices.

5. A seal as defined in claim 4 wherein said apices are normally disposed below the upper edges of said side walls and are adapted to be raised upwardly, toward but no higher than the level of said side wall upper edges, upon lateral compression of said seal.

6. A seal as defined in claim 4 wherein the configuration of said top wall and said bottom wall are the same.

7. A seal as defined in claim 1 characterized by having two planes of symmetry, one horizontal and one vertical.

8. A seal as defined in claim 3 wherein said one of said cells has a smaller transverse width than said other two cells.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,765 ,784 Dated October 16, 1973 Inventor) Stewart C. Watson et a1.

It is certified that error appears in the aboveidentified patent and that said Letters Patent are hereby corrected as shown below:

On the cover sheet insert:

[30] Foreign Application Priority Data Aug. 20, 1970 Australia -2263/70 Aug. 20,1970 Australia 22 65/70 Signed and sealed this 9th day of July 1974.

(SEAL) Attest:

MCCOY M. GIBSON, JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents RM PO-1050 (IO-69) USCOMMDC 60375-F'69 U.S. GOVERNMENT PRINTING OFFICE I959 O366-334,

Claims

1. A seal for expansion joints comprising an elongated hollow strip having opposite side walls; a top wall ; and a bottom wall, the junctures of said side walls with said top wall and said bottom wall being rounded; and an integral, internal, reinforcing network of web sections, said network comprising a plurality of laterally spaced, upper web sections extending vertically downwardly from said top wall in generally parallel relation with said side walls, a plurality of laterally spaced, lower web sections extending vertically upwardly from said bottom wall in generally parallel relation with said side walls and substantial vertical alignment with said upper web sections, a plurality of generally diamond shaped cells including a centrally located cell disposed in a side by side relation between said side walls, each of said diamond shaped cells being bounded solely by a plurality of other web sections connected at their upper and lower ends, respectively, to one of said upper and one of said lower web sections, said central cell in cross-section being smaller than the others of said diamond shaped cells and symmetrical about a vertical axis, said strip being resilient and flexible and adapted, when subjected to pressure against said side walls, to be compressed whereby to narrow the width of said central cell and tend to straighten the web sections by which said central cell is bounded to provide increased support for the top and bottom walls of said strip.