US2118330A - Grating expansion joint for bridges - Google Patents

Description

Patented' May 24, 1938 UNITED STATES PATENT OFFICE Ernest L. Tarot, Brooklyn, N. Y., assigner to Kerlow Steel Flooring Co., Jersey City, N. J., a corporation of New Jersey Application February 17, 1937, Serial No. 126,102

Claims.

This invention relates to grating expansion joints for bridges and the like and has for its object to eliminate disadvantages inherent in many of the previously used types of such joints. Another object is to provide such an expansion joint which is especially adapted for use with the type of metal gratings which we manufacture.

One common form of expansion joint on the highway portion of bridges has been a butt type joint which is practically vclosed in hot summer weather but wide open in cold weather. In many places the distance or sizeof gap which is open in such types of expansion joint in cold weather may be as much as about three inches, which is too large a 'gap for trame to pass over smoothly, with the result that heavy trucks cause substantial impacts which needlessly impair the joint. Another type of expansion joint in use has involved oppositely extending tapered fingers which overlap longitudinally various amounts according to the temperature or season. An objection to this type of expansion joint is that ice forms on `the vsides of the overlapping lingers due to their being laterally spaced only a small amount, perhaps about a quarter of an inch. This formation of ice is sufliciently serious to impede the functioning of the expansion joint and it has been necessary tohave workmen with blow torches go around and melt the ice thus formed. Under this invention the tendency of ice to form at the expansion joint isjsubstantally minimized.

Referring to the drawing, Fig. 1 is a top plan view of one embodiment of this invention.

Fig. 2 is a section on the line 2-2 of Fig. l.

Fig. 3 is a section on the same line of Fig. l, but with the grating sections Widely spaced, as in very cold weather.

Fig. 4 illustrates a modied type of expansion joint.

Fig. 5 shows a further type of expansion joint adapted for use with grating sections.

Fig. 6 is a lift or bascule type bridge for which the expansion joint of Fig. 5 is particularly adapted when used with my open grating door.

A grating section I0 on a bridge or the like is movable with respect to the end of an adjacent grating section II, so that these adjacent end portions are quite close together in very hot weather but contract and form a space, I2, between them which may vary up to possibly three inches in the very coldest weather. Each grating section, I0 and II, may be of any convenient length and may include several or any desired number of such lengths which are fastened together for expansion or contractile movement as a unit. Preferably each such section is anchored to one of its transverse supporting beams adjacent its central portion in order that the ex pansive movement of each section may be on both sides of such anchorage. Ordinary beams I3 and Il, extend transversely across the bridge for supporting these grating sections we manun facture. Each grating section is preferably comprised of straight bars, I5, and spacing bars, I6, which are riveted or welded to the straight bars. Any convenient type of spacing bar may be used such as that illustrated or the substantially normal type bar. vA splicing section, I1, is provided to support the adjacent end portions of the gratings, Ill and II, and also for the purpose of providing a ller or bridge when the gap, I2, is large, in order that vehicular trailic may -travel over the open gap with a minimum amount of vibration. This splicing section includes a number of longitudinal members arranged contiguous alternate longitudinal members of the grating sections, or, if desired, they may be arranged contiguous each longitudinal member of the grating sections I0 and II. As illustrated in Fig. 1, this splicing section has its longitudinal portions arranged contiguous alternate longitudinal grating members and connected tothe longitudinal straight bars by headed securing means, I8, passing through elongated slots, I9, located below the spacing bars in order that limited relative movement may take place between the splicing section and each grating section.

The longitudinal portions of the splicing section Il are preferably supported on the transverse beams, I3 and I4, as illustrated and so shaped as to t between these beams and contiguous their sides so that the splicing section longitudinal portions are substantially fixed while the adjacent ends of the grating sections, I0 and I I, are movable with respect thereto with temperature change. 'I'he longitudinal portions of the splicing section may be connected by spacing portions below the longitudinal straight bars of the grating sections, I0 and Il, as suggested in my Patent 2,014,912, dated September I7-, 1935. 0r, if desired, the various longitudinal bars of the splicing section I1 may be disconnected except as they are connected through the grating sections. The top of the splicing sections preferably is contiguous the under side of the spacing bar, I B, to assist in supporting the overhanging ends of the grating sections. In the embodiment illustrated, the headed securing means, I8, which may be either a bolt or a rivet, is xed with respect to the portion of the straight bars, l5, through which it passes beneath the spacing bar, I6, while the slots, i9, are shown as being provided in the splicing section.

The central portion of the splicing section is raised as shown at 2|, to a height substantially ilush with the top of the grating sections, i0 and Il, so that when the grating sections are widely spaced apart, this raised portion, 2 I, serves as a bridging element to facilitate smooth travel of vehicular traic over the joint in cold weather without objectionable impact. As shown in Fig. 1, this raised or bridging portion. 2i, lies contiguous alternate straight bars, I5. If it is de sired for the splicing section longitudinal members to be contiguous each of the longitudinal straight bars, l5,l thenvthe raised portion, 2|, in alternate straight bars must be considerably shorter than that shown in Figs. 1 to 3, or else the bent spacing bar, I6, will have to be terminated at alternate straight bars, I5, back from the ends of alternate straight bars of each section rather than allowed to extend to the ends of alternate straight bars as illustrated in Fig. 1.

In Fig. 4, the'long'itudinal portions, I'la, of the splicing section are arranged between rather than on the same side of the straight bars, lia, of each grating section. .This arrangement has the advantage of enabling the longitudinal straight bars of. each grating section to overlap each other longitudinally, if desired. In each embodiment the bent bars must be shaped to allow the necessary relative movement between the splicing section straight bars and the grating sections. Here again the longitudinal portion of the splicing sections may be laterally connected or not, as desired, below the straight bars of the grating sections.

In Fig. 5 is shown another form of expansion joint adapted for use with grating sections. This type of joint will be seen to comprise overlapping straight bar extensions, 23, which are formed beyond the termination of the bent bars, I6b, and the straight bars, l5b, are shown as being laterally spaced about midway between pairs of the straight bars of the other grating section. An expansion joint of this type is preferably used without the splicing section described in connection with Figs. 1 to 4, inclusive. Since the spacing between straight bars oi'. a grating section is generally inV excess of two inches, the lateral spacing between the overlapping ngers, 23. is generally in excess of an inch, with the result that any tendency for ice to form on the sides of the overlapping bars, 23, is greatly minimized. The expansion joint shown in Fig. 5 is especially adapted for use with lift or bascule type bridges the adjacent end portions oi which may be slightly overlapped. ,Such a bridge is illustrated in outline in Fig. 6, where the bascules 2li are pivoted at 25, as is customary.

Among the advantages of this invention may be mentioned the elimination of any exposed surfaces adjacent the expansion joint on which substantial quantities of snow or ice may collect. The relatively narrow edge surfaces provided in gratings allow for very little snow or ice to collect. The provision of a raised or bridging part to the splicing section permits vehicular traffic to travel over a wide gap in cold weather with little or no impact comparable to what might occur if the raised or bridging portions were absent. While the splicing section has been illustrated as being anchored and movable with respect to each grating section, nevertheless, it will be understood that if desired this splicing section may be fastened with respect to eithergrating section and movable with respect to the other. The splicing section of this invention may serve the combined oillce of both a splicing section to support the ends of adjacent gratings and also as a bridging part oi an expansion joint. There is little or no tendency for ice to form between longitudinal portions of the expansion joint,`

either in Fig. 5 or in Figs. 1 to 4. It the adjacent ends of the grating sections are oi' the type illustrated in Fig. 5, these sections may have their straight bars in substantial alignment when the raised portion of a splicing section may be placed contiguous each straight bar, or it desired, a. splicing section between adjacent straight bars as in Fig. 4 may be used with the grating ends of the type shown in Fig. 5. In event an unusually hot day may expand the grating sections shown `in Fig. 5 until the ends of the bars, 23, abut the spacing bars, lib, that should not be objectionablev for it shouldbe a relatively simple matter for either the ends, 23, or the bent bars, I6b, to be bent by expansion and contract as may be necessary. From Fig. 5, it may be seen that if the ilngers, 23, have their ends abutting the bent bar, llb, the .tendency of any of the bars to be bent is balanced due to the symmetrical arrangement of the spacing bars, lib.

I claim:

1. A grating expansion joint between sections for a bridge and over which vehicular tralc is adapted to pass, comprising longitudinal members adapted to move toward and from each other as portions of. said bridge expand and contract, a longitudinal member overlapping portions of said first mentioned longitudinal members, having an extension substantially ush with the top of said sections, adapted to -bridge any gap between them and to assist in directly supporting vehicular trafllc as it. pass over such gap, said second mentioned longitudinal member being slidably secured to the rst mentioned longitudinal members so that it need not move with them.

2. A grating expansion joint between sections for a bridge and over which vehicularv trame is adapted topassI comprising longitudinal members adapted to move toward and from each other as portions of said bridge expand and contract, a longitudinal member overlapping portions of said first mentioned longitudinal members, having an extension substantially flush with the top of said sections, adapted to bridge any gap between them and to assist in directly supporting vehicular trailcas it passes over such gap, said second mentioned longitudinal member being slidably secured to at least one of the iirst mentioned longitudinal members so that it need not move with them, and means for holding said second mentioned longitudinal member against movement with at least one of said rst mentioned longitudinal members.

3. In a bridge or the like paved with metal grating sections adapted to be moved toward and from each other longitudinally with expansion and contraction of said sections, each section including longitudinal substantially straight bars having 'spacing bars secured between them and of less depth than the straight bars, a splicing section having longitudinal members secured to at least some of. the longitudinal members of said sections by headed securing means fastened to the longitudinal Amember of one section and passing through a longitudinal elongated slot in the contiguous longitudinal member, said spliced section having an elevated portion centrally thereof rising to a height such that its top is substantially flush with the tops of said grating sections.

4. In a bridge or the like paved with metal grating sections adapted to be moved toward and from each other longitudinally with expansion and contraction of said sections, each section including longitudinal substantially straight bars having spacingV bars secured between them and of less depth than the straight bars, the straight bars of one section being laterally displaced from the straight bars in the other grating section, an expansion joint being formed between said sec tions so that a longitudinally extending portion of one section substantially overlaps another longitudinally extending portion of theother section to prevent the formation of an open gap longitudinally between the sections at the top or tread surface of said paving, said joint including a splice section secured to the longitudinal straight bars of each section below their spacing bars and having an extension substantially flush with the top of said sections at their ends.

5. In a bridge or the like, an expansion joint formed between metal grating sections which are adapted to be moved toward and from each other longitudinally with expansion and contraction of said sections, each section including longitudinal substantially straight bars having spacing bars secured between them and of less depth than the straight bars, spaced transverse beams on which said sections are supported, a splicing section overlapping the adjacent end portions of said sections in said joint, and being supported at its ends on adjacent portions of said sections, a slidable connection between said splicing section and the adjacent end portions of said grating sections, said splicing section being anchored to at least one of said transverse beams.

6. In a bridge or the like, an expansion joint formed between metal grating sections, which are adapted to be moved toward and from each other longitudinally with expansion and contraction of said sections, each section including longitudinal substantially straight bars having spacing bars secured between them, spaced transverse beams on which sections are supported, a splicing sec-v tion overlapping the adjacent end portions of said sections and including longitudinal bars slidably secured to longitudinal bars of each grating section, said splicing section being located contiguous and on opposite sides of adjacent longitudinal bars in said grating sections. the longitudinal bars of the splicing section having an extension which is substantially flush with the tops of said grating sections.

7. An expansion joint between metal grating sections comprising a splicing portion attached to at least one of said grating sections, having a part which is substantially flush with the tops of said gratingsections and which is adapted to longitudinally overlap the ends of said grating sections.

8. The combination with a pair of metalgrating sections adapted to have a space between their adjacent ends, of longitudinal members overlapping said sections, forming anexpansion joint and provided with raised portions substantially ilush with the tops of said grating sections at their ends, and supports for said grating sections and longitudinal members.

9. A grating expansion joint for a bridge and over which vehicular trailic is adapted to pass, comprising longitudinal members adapted to move toward and from each other as portions of said bridge expand and contract, a longitudinal member overlapping portionsl of said iirst mentioned longitudinal members, adapted to bridge any gap between them and to assist in directly supporting vehicular tramo as it passes over such gap, said second mentioned longitudinal member being slidable relatively to at least one oi' the iirst mentioned longitudinal members, said second mentioned longitudinal member having its end portions provided with supporting means which is in addition to any connection to either of the ilrst mentioned longitudinal members.

l0. A grating expansion joint for a bridge over which vehicular trafilc is adapted to pass, comprising grating sections which are adapted to be moved relatively toward and from each other longitudinally with expansion and contraction oi said sections, each section including longitudinal substantially straight bars having bent spacing bars secured between them and of less depth than the straight bars, splicing bars secured to at least some of the straight bars of said sections below the spacing bars and provided with raised portions substantially ush with the tops of said sections and bridging any gap between the ends of no more than alternate ones of said straight bars when the spacing bars extend substantially

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