US3325842A - Bridge bearings - Google Patents

Description

June 20, 1967 ca. D. SPENCER 3,325,842

BRIDGE BEARINGS Original Filed Jan. 29, 1962 4 Sheets-Sheet .1

l V13. \"IT )R. GEOFFREY D. SPENCER A Horn 9 y June 20, 1967 G. D. SPENCER BRIDGE BEARINGS 4 Sheets-Sheet 2 Original Filed Jan. 29, 1962 FIG. 4

Attorney June 20, 1967 e. D. SPENCER 3,325,842

BRIDGE BEARINGS Original Filed Jan. 29, 1962 4 Sheets-Sheet 3 INVEY'IOR, GEOFFREY D. SPENCER Attorney June 20, 1967 D. SPENCER BRIDGE BEARINGS 4 Sheets-Sheet 4 Original Filed Jan. 29, 1962 FIG. 8

GEOFFREY D. SPENCER W Attorney United States Patent 3,325,842 BRIDGE BEARINGS Geoffrey Dennis Spencer, Don Mills, Ontario, Canada (11 Royal Doulton Drive, Toronto, Ontario, Canada) Continuation of application Ser. No. 169,564, Jan. 29, 1962. This application Nov. 5, 1964, Ser. No. 410,825 16 Claims. (Cl. 14-16) This invention relates to bearings and more particularly, to bridge bearings.

This application is a continuation of my now abandoned application Ser. No. 169,564 filed Jan. 29, 1962.

Corrosion due to the corrosive substances normally existing in the atmosphere is a considerable problem to the engineer. However, in colder climates, on bridges and the like, it is an even greater problem. Snow and ice have to be removed from the bridge surface to permit the regular flow of tratiic and reduce the weight borne by the bridge. This removal is usually accomplished by spreading inorganic salts over the bridge surface, and as a result of the thawing which ensues the corrosive salts are carried down to the bridge bearings, thus accelerating their corrosion and frequent maintenance replacement.

It is the main object of this invention to provide an improved bearing.

It is another object of this present invention to provide an improved hearing which will withstand corrosion for a greater period than bearings of conventional structure.

However, bridge bearings whether they be of the improved type which will be described hereafter, or of conventional structure, will usually require removal or adjustment at some time in their lives. Conventional bearings, as a rule, comprise a roller or rocker which is held between a top plate and a bottom plate by pins or pintles which engage aligned holes in the rocker and top and/or bottom plates. The top and bottom plates are respectively secured to the adjacent end of a bridge I-beam and the top of a bridge pier. Thus, if a bearing has to be removed, the entire road-supporting bed has to be raised a height equivalent to the combined length of the pintles which as a rule is equal to the sum of the heights of the top and bottom plates.

Sliding bearings also incorporate pintles which necessitate the same elevation of the road bed should they be required to be removed.

In accordance with alternative embodiments of the present invention, it is not necessary to raise the road bearing surface any considerable distance. It is sufiicient to remove the pressure exerted by the road bed on the hearing before the hearing may be removed.

It is, therefore, another object of this inventon to provide an improved bridge hearing which may be easily installed or replaced.

It is another object to provide an improved bearing which may be more easily and economically manufactured.

In accordance with the present invention, the inventor provides a bridge bearing comprising a top plate and a bottom plate each having a main axis disposed transversely to a direction of thrust, bearing means having an upper and a lower surface disposed between said plates, a portion of said upper and lower surfaces in contiguous engagement with the adjacent surfaces of said top and bottom plates respectively, and removable means at each end of said bearing means adapted to connect said bearing means to said top and bottom plates wh-ile permitting movement of said bearing means about an axis substantially parallel to the main axes of said plates.

In accordance with another embodiment of the present invention, the inventor provides a bridge bearing comprising a top plate and a bottom plate having main axes disposed transversely to a direction of thrust, bearing means secured between said plates and adapted to move about a transverse axis parallel to the main axes of said plates, an elastomeric foam composition substantially filling the remaining volume intermediate said plates, and an elastomeric sheath external to said foam and extending about said bearing at least between said top and bottom plates in a substantially air and watertight relationship therewith.

These objects and other features of the invention will be more fully understood from the following description and drawings in which:

FIGURE 1 is a general perspective view of one embodiment of a bearing in accordance with the present inven tion showing its relationship with a bridge I-beam and pier;

FIGURES 2, 3 and 4 are partial fragmentary perspective views of various types of bearings embodying the invention;

FIGURE 5 is a fragmentary side view of an alternative embodiment of the invention;

FIGURE 6 is a view taken from line 66 of FIG- URE 5;

FIGURE 7 is a partial fragmentary perspective view of the embodiment illustrated in FIGURE 5;

FIGURE 8 is a schematic transverse section through an alternative embodiment of the invention in which several of the components are shown in dotted outline;

FIGURE 9 is a fragmentary transverse sectional view of an alternative embodiment of a bearing in accordance with the invention; and

FIGURE 10 is an enlarged partial sectional view of an alternative embodiment of a bearing in accordance with the invention;

FIGURE 11 is an enlarged partial sectional view of another alternative embodiment of a bearing in accordance with the invention.

In FIGURE 1, a bridge pier is shown in dotted outline as 10 and an adjacent I-beam is indicated at 11. Intermediate I-beam 11 and the top surface of pier 10-, one embodiment of a bearing in accordance with the present invention is illustrated and indicated generally at 12. This bearing comprises a top plate 13 and a bottom plate 14, disposed one above the other. Top plate 13 is secured to the adjacent surface of I-beam 11 by means of four bolts indicated at 15, 16, 17 and 18. Bottom plate 14 is similarly secured to the top surface of pier 10 by bolts, which are not shown, but which pass through holes 19 and 20. Intel- mediate plates 13 and 14, a roller bearing 21 is placed. For the purposes of this specification and claims, such roller bearings and the equivalent components of the various forms of bearings will be defined as bearing means. In top plate 13, two slots 24 and 25 are provided, one adjacent each end on the longitudinal axis of plate 13 which is transverse to the main axis of the bridge and the direction of the principal thrusts which will be exerted upon the bearing by the bridge surface supported by I- beam 11. Similarly, bottom plate 14 has two slots, one adjacent each end, one of which is indicated at 26. These slots are vertically aligned with their corresponding slots in top plate 13. On the left hand side of roller 21, as illustrated in FIGURE 1, a pintle such as 27 is secured by means of bolts such as 28, 29, 30 and 31. A corresponding pintle is also provided for the other side. It will be observed that the pintle 27 has terminal projections 33 and 32, at the bottom and top ends respectively, which have a substantially involute form to permit the pintle to rock within the slots. The corresponding pintle on the remote side has similar projections.

When a thrust in the direction of the arrow is exerted by I-beam 11, on bearing 12, the roller will be caused to roll about an axis parallel to the main axes of the top and bottom plates in the conventional manner.

If any torque or lateral force is exerted on'the bearings, then a lateral movement of the hearing will be prevented by the engagement of the projections on the respective pintles with the adjacent slots in the top and bottom plates.

It will thus be seen that if, under any circumstances the bearing has to be removed from the bridge structure, that instead of the bridge being jacked up to the distance required by the conventional structure, with the present bearing, the bridge will only be required to be jacked up a suflicient distance such that the pressure on the bearing Will be removed, and by loosening the bolts such as 28, 29, 30 and 31 and the corresponding bolts on the other side, the roller 21 may be slid out and replaced by a roller of similar structure.

It will also be observed that this structure minimizes the machining required. The pintles and the mating slots can be used substantially as they are cast, thus eliminating the necessity of any machining.

The embodiment illustrated in FIGURE 1 may be encapsulated as will be described later, however, in the form illustrated in this figure, the slots such as 26 in the bottom plate provide an outlet for Water or other such liquid. In conventional bearing structures, the water tends to accumulate in the pintle receiving slots thus accelerating corrosion.

FIGURES 2 through 7 illustrate alternative embodiments of the present invention in which various types of bearings, namely roller bearings, rocker bearings, plate bearings, and combined roller and rocker bearings, are encapsulated to reduce corrosion. In FIGURE 2, the hearing is a conventional roller bearing comprising three rollers 40, 41 and 42, secured together by a terminal bar such as 43. These rollers are mounted intermediate top and bottom plates 44 and 45 respectively, and on the top surface of plate 44 a second plate 46 is mounted. Bottom plate 45 is provided with four holes by means of which the bearing may be secured to the bridge pier and top plate 46 is similarly provided With four holes to enable the hearing to be secured to the adjacent bridge I-beam. Around the roller bearings in the space intermediate top and bottom plates 46 and 45 respectively, and around the side thereof, an elastomeric foam 50 is disposed and this foam provides a substantially air-tight seal. This elastomeric foam may be formed from any suitable material such as silicone rubber, urethane or neoprene and the structure is preferably such that the individual cells of the foam are discrete. If a foam with communicating cells is employed, then it may be impregnated or saturated with a non-corrosive liquid or gas.

In each of the embodiments illustrated in these and FIGURES 2 through 7, a second layer of elastomeric material 51, such as neoprene, silicone rubber, urethane, or the like, is moulded so as to provide a substantially air and water-tight sheath for the bearing. This second layer of elastomer 51 may be vulcanized or similarly treated for durability.

The structures of the embodiments of FIGURES 3 and 4 are of conventional form except that the elastomeric foam 50' is again present intermediate the top plates 46' and bottom plates 45; and again a second elastomeric sheath 51 is moulded about substantially the entire structure to provide an air and water-tight sheath.

In order to fabricate the structures illustrated in FIG- URES 2 through 7, the bearing is placed in a suitable mould and a suitable mixture of liquid elastomer, hardener and a foaming agent is injected into this mould. It

will of course, be understood that the mould is provided with suitable breather holes so that substantially all the air present will be expelled. The foam is then allowed to set or until it is in a substantially solid condition and the bearing is then placed in a second mould or a second mould is placed around the hearing so that the outer surface of the elastomer foam provides an inner surface for the second mould, and a suitable elastomer such as neoprene, silicone rubber, urethane or the like in liquid form is injected to surround the bearing and form a second sheath 51 in the manner shown in FIGURES 2 through 4, where it is allowed to set until substantially hard. Any of the well-known hardeners may be added to the clastomer to accelerate the curing or the outer sheath may be vulcanized by heating.

It will be seen that the resultant structure from the above process provides a bearing which is substantially impervious to moisture and has improved resistance to corrosion.

The structures illustrated by FIGURES 5 through 7 inclusive, are encapsulated in an elastomeric foam and an external elastomeric sheath in the same manner as specified in the description of FIGURES 2 through 4, and it will be apparent that this method may be employed for the treatment of bridge hearings in situ.

Referring now to FIGURE 5, the bearing, generally indicated at 60, comprises a top plate 61 and a bottom plate 62 between which a roller 63 having an arcuate upper surface 64 and a substantially arcuate lower surface 125 is mounted with its upper and lower surfaces 64 and 125 respectively, in contact with the under and top surfaces of the top plate 61 and bottom plate 62 respectively.

There are no slots present in either the top or bottom plates as is illustrated in the embodiment illustrated in FIGURE 1. Instead top plate 61 is provided with two downwardly depending lugs 65 and 66 at either end of its main axis. Similarly, bottom plate 62 is provided with two corresponding upwardly extending lugs 67 and 68 disposed in vertical alignment with the corresponding lugs on the top plate 61 and in alignment with the main axis of the bottom plate 62. As formerly, on each end of the roller 63 a terminal pintle such as 69 and 70 is secured by means of bolts such as 71, 72, 73 and 74. These pintles have substantially the same configuration as the pintles illustrated in FIGURE 1 only they are provided with two spaced apart lugs 75, 76 on their top ends and two spaced apart lugs 77, 78 on their bottom ends. Intermediate these lugs, slots 79 and 80 respectively, are provided to engage with the corresponding depending and u-p-- Again this structure performs the same functions as a conventional hearing but has the advantage that the several lugs and .interengaging slots therewith may be cast and no further machining may be required. The removal of the hearing from the bridge structure is again accomplished by raising the road bed sufficiently so that the pressure is taken from the top plate of the bearing and by removing the respective bolts such as 71, 72, 73 and 74, the hearing may be slid out.

FIGURE 8 is a transverse sectional view of a modified embodiment of the embodiment illustrated in FIGURE 5 with the roller 63, the top plate 61 and the bottom plate 62 being shown in dotted outline. However, it has been found that under certain thrusts the outer sheath 51 tends to bulge outwardly at the points 101, 102, 103 and 104 as indicated. To overcome or restrain this tendency, steel, fiberglass or similar corrosion- resistant meshes 105 and 106 may be embedded in the upper and lower surfaces of the sheath 51 in the manner shown. These meshes 105 and 107 respectively, on their side walls. Side wall 151 which may be of unitary construction or comprised of two or more distinct portions suitably secured together after assembly, has an inwardly projecting flange 108 adjacent its top edge and a similar flange 109 adjacent its bottom edge. These flanges engage channels 106 and 107 respectively, in the manner shown. For further security, a layer of suitable adhesive 110 may be provided as shown in FIGURE 10.

To make the engagement between these cooperating flanges and channels further secure, a corrosive-resistant strap-receiving member 111 is secured around the top edge of sheath 151 and a similar member 112 is secured around the bottom edge of sheath 151 in the manner shown. Member 111 and member 112 are each provided with a channel 113 and 114 respectively, in which steel straps 115 and 116, respectively, are fixed by conventional means. Strap-receiving members 111 and 112 are as illustr-ated, fabricated from fiberglass or a similar material of substantially equivalent strength. This arrangement prevents the steel straps from cutting into the rubber sheath 151.

In the embodiment illustrated in FIGURE 11, the several parts are numbered similarly to those corresponding parts of FIGURE 10. However, in this embodiment, sheath 151 has a plurality of longitudinally extending corrugations therein such as 152. These corrugations serve to provide an effective height to the sheath which exceeds the vertical distance between top and bottom plates 61 and 62 respectively so that stresses such as tend to extend or distort the side walls will be compensated for and any tendency to rupture the side walls reduced. These corrugations may also be employed in the other embodiments described. An alternative mode of providing the greater eflective height of the side wall would be by the provision of an inwardly or outwardly curved sidewall such as illustrated in dotted outline by 153 and 153' respectively. In this embodiment, the elastomeric foam has been replaced by a suitable non-corrosive liquid 200 which also extends the life of the bearing. It will also be understood that this liquid may be substituted for the elastomeric foam in each of the embodiments described. However, whereas the outer surface of the elastomeric foam provided an inner wall for the second mould, in the fabrication of such embodiments as employ a liquid, instead of the elastomeric foam, an inner wall would have to be provided for the formation of the outer sheath 151.

While the invention has been described with reference to several particular embodiments, it will be understood that various modifications and changes may be made without departing from the spirit and scope of the invention except as defined in the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A bridge bearing comprising, in combination, a top plate and a bottom plate, bearing means having an upper and a lower surface disposed between said plates, a portion of said upper and lower surfaces in contiguous engagement with the adjacent surfaces of said top and bottom plates respectively, and laterally removable pintle means secured to each end of said bearing means, said pintle means extending between said top and bottom plates and engageable therewith to permit rocking movement of said bearing means.

2. -A bridge bearing as claimed in claim 1 in which said top and bottom plates each have at least two slots therein one adjacent each end, and said removable connecting means each include an upwardly extending projection and a downwardly extending projection co-operable with said slots of said top and bottom plates.

3. A bridge bearing as claimed in claim 1 in which said top plate has at least one downwardly extending projection adjacent each end thereof, and said bottom plate has at least one upwardly extending projection adjacent each end thereof, said pintle means including slots co-operable with said projections on said top and bottom plates.

4. A bridge bearing comprising a top plate and a bottom plate having main axes disposed transversely to a direction of thrust, bearing means secured to and between said plates and adapted to move about a transverse axis parallel to the main axes of said plates, an elastomeric foam composition substantially filling the remaining volume intermediate said plates, and an elastomeric sheath external to said foam and extending about said bearing at least between said top and bottom plates in a substantially air and water-tight relationship therewith.

5. A bridge bearing as claimed in claim 4 in which said elastomeric sheath extends continuously around said bearing.

6. A bridge bearing as claimed in claim 4 in which said elastomeric sheath extends continuously around said bearing and also extends over said top and bottom plates to substantially enclose said plates.

7. A bridge bearing as claimed in claim 4 including means for securing said sheath tosaid top and bottom plates.

8. A bridge hearing as claimed in claim 4 in which said top and bottom plates each have an inwardly extending channel extending around their side walls and said sheath includes an inwardly extending projection adjacent each of the top and bottom ends thereof each co-operable with the corresponding channel in the top and bottom plates respectively.

9. A bridge bearing as claimed in claim 4 in which said top and bottom plates each have an inwardly extending channel extending around their side walls, said sheath including an inwardly extending projection adjacent each of the top and bottom ends thereof each co-operable with the corresponding channel in the top and bottom plates respectively, and strap means encircling said sheath adjacent the top and bottom ends thereof to hold said sheath in air and water-tight engagement with said plates.

10. A bridge bearing comprising a top plate and a bottom plate each having a main axis disposed transversely to a direction of thrust, bearing means having an upper and lower surface disposed between said plates, a portion of said upper and lower surfaces in contiguous engagement with the adjacent surfaces of said top and bottom plates respectively, laterally removable means at each end of said bearing means adapted to engage said bearing means to said top and bottom plates while permitting movement of said bearing means about an axis substantially parallel to the main axes of said plates, an elastomeric foam substantially filling the remaining volume intermediate said plates, and an elastomeric sheath external to said foam and extending about said bearing at least between said top and bottom plates in a substantially air and Water-tight relationship therewith.

11. A bridge bearing comprising a top plate and a bottom plate having main axes disposed transversely to a direction of thrust, bearing means secured between said plates and adapted to move about a transverse axis parallel to the main axes of said plates, an elastomeric sheath having vertical walls extending about said bearing at least between said top and bottom plates in a substantially air and water-tight relationship therewith, and a non-corrosive medium substantially filling the remaining volume intermediate said plates.

12. A bridge bearing as claimed in claim 11 in which said top and bottom plates are spaced apart a predetermined distance and said sheath has vertical walls having a height greater than the distance between said plates.

13. A bridge bearing as claimed in claim 11 in which said top and bottom plates are spaced apart a predetermined distance and said sheath has corrugated walls.

14. A bridge bearing as claimed in claim 12 in which said non-corrosive medium is a fluid.

15. A bridge bearing as claimed in claim 14 in which 809,071 1/ 1906 Motley l416 said vertical walls have a height greater than the distance 3 13 493 12 19 3 Rinker 14 1 X between said plates. 7

16. A bridge bearing as claimed in claim 14 in which OTHER REFERENCES sald sheath has Corrugated Walls- 5 Civil Engineering, publication, August 1956, page 86 References Cited felled UNITED STATES PATENTS CHARLES E. OCONNELL, Primary Examiner. 4841971 10/1892 Morison N. C. BYERS, Assistant Examiner.

776,572 12/1904 Ward 14-16 10

Claims (1)

10. A BRIDGE BEARING COMPRISING A TOP PLATE AND A BOTTOM PLATE EACH HAVING A MAIN AXIS DISPOSED TRANSVERSELY TO A DIRECTION OF THRUST, BEARING MEANS HAVING AN UPPER AND LOWER SURFACE DISPOSED BETWEEN SAID PLATES, A PORTION OF SAID UPPER AND LOWER SURFACES IN CONTIGUOUS ENGAGEMENT WITH THE ADJACENT SURFACES OF SAID TOP AND BOTTOM PLATES RESPECTIVELY, LATERALLY REMOVABLE MEANS AT EACH END OF SAID BEARING MEANS ADAPTED TO ENGAGE SAID BEARING MEANS TO SAID TOP AND BOTTOM PLATES WHILE PERMITTING MOVEMENT OF SAID BEARING MEANS ABOUT AN AXIS SUBSTANTIALLY PARALLEL TO THE MAIN AXES OF SAID PLATES, AN ELASTOMERIC FOAM SUBSTANTIALLY FILLING THE REMAINING VOLUME INTERMEDIATE SAID PLATES, AND AN ELASTOMERIC SHEATH EXTERNAL TO SAID FOAM AND EXTENDING ABOUT SAID BEARING AT LEAST BETWEEN SAID TOP AND BOTTOM PLATES IN A SUBSTANTIALLY AIR AND WATER-TIGHT RELATIONSHIP THEREWITH.

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