Mechanical bridge assembly and method

CROSS-REFERENCE TO RELATED APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

The field of the invention is mechanical bridges and more specifically bridges including spans that are openable.

Bridges are required to facilitate convenient rail and vehicular traffic over rivers, streams, dams and the like (hereinafter collectively referred to as rivers). While bridges are necessary, unfortunately bridges can impede passage of vessels along rivers there below. In order to accommodate both rail and vehicular traffic over rivers and travel along the rivers by ships, barges, etc, bridge designers have developed several different mechanical type bridges including one or more bridge spans that can open and close.

One mechanical bridge type is generally referred to as a vertical-lift bridge. A vertical-lift bridge typically includes vertical towers at either end of a bridge span. When positioned for vehicular traffic, the span is in a low position where a top surface is aligned with top surfaces of adjacent bridge spans. To accommodate travel below the bridge span the span can be raised between the towers.

While vertical-lift bridges can accommodate both river and vehicular travel, these bridges have several shortcomings. First, vertical-lift bridges, while accommodating some river travel, still restrict travel as the lifted span remains above the area through which travel occurs. Second, the motors and other mechanical equipment required to lift the bridge span are relatively large and therefore expensive. In addition, because of the mechanics involved with vertical-lift bridges, maintenance costs for vertical lift bridges are relatively high.

Another mechanical bridge type is a swing span bridge. A typical swing span bridge includes a moveable span that pivots about a vertical axis to provide required opening clearance for navigation traffic. Swing spans are typically symmetrical with equal length cantilevers to each side of the vertical axis. Some swing span bridges, however, are configured with unsymmetrical cantilevers that are counterweighted to balance the bridge. Swing span bridges are advantageous as they provide unlimited vertical clearance for river bound traffic when the span is open.

Unfortunately swing spans also have several shortcomings. First, when a swing span is horizontally pivoted into the open position the span ends are generally considered to be navigational hazards. The span ends are directed against movement of water bound traffic and therefore are prone to vessel collision. Thus, often substantial fender systems are required to protect the span and vessels in the area. Second, swing spans typically require twice as much moveable length span as other mechanical span designs to provide the same opening width. This is because, as indicated above, most swing span bridges require equal length span segments cantilevered about the vertical pivot point. Third, the mechanical components required to manipulate the large span sections are generally relatively large and therefore relatively expensive.

Yet one other mechanical bridge type is referred to generally as a bascule type bridge. A typical bascule bridge includes a leaf that pivots about a horizontal axis to provide a required opening and clearance for river bound traffic. Counterweights are usually provided to balance the weight of the span and minimize the operating requirements on the drive machinery. The bascule span bridges provide unlimited vertical clearance when open.

Bascule bridges, like the other bridge types described above, have several shortcomings. First, the counterweight required to balance the bascule span is typically rather large. As most mechanical bridges are relatively low to the water, the counterweights are typically positioned above a span adjacent the moveable span. To support the counterweight these bridge types often require large and expensive overhead framing systems and massive foundations below the spans to handle the overturning moments that occur. Second, the mechanics required to control a bascule bridge are extremely complex and therefore expensive. Third, bascule bridges requiring massive counterweights are relatively unsafe in certain geographic areas that are subject to seismic tremors.

Thus, there is a need for a mechanical bridge that is simple, relatively inexpensive, provides unlimited vertical clearance and that does not require massive overhead or counterweight components.

BRIEF SUMMARY OF THE INVENTION

It has been recognized that a relatively simple bridge design can overcome many of the shortcomings of the prior art bridges described above. To this end, by moving a bridge span essentially within a single vertical plane from a supporting position into a storage position, system mechanics can be greatly simplified without sacrificing safety. To this end, in one embodiment, an openable span is moved laterally from a supporting position and then longitudinally along the side of an adjacent span to open a space for water bound traffic. In another embodiment an adjacent span is removed from its position adjacent an openable span and then the openable span is moved at least in part into the adjacent position to open a space for water bound traffic.

Thus, one object of the invention is to provide a simplified openable bridge design. This object is accomplished by minimizing required vertical span movement. In some embodiments there is no vertical span movement while in other embodiments vertical movement is limited in several ways. First, the vertical distance of movement is minimized. Second the size of the span that has to be moved is limited. To this end, when a first span is vertically moved and then a second span is horizontally moved into the space originally occupied by the first span, the first span is only half as large as the second span and hence a minimally sized span is vertically moved.

Another object is to provide a relatively safe mechanical bridge. To this end, because vertical span movement is limited, above deck structure is minimized. Because above deck structure is minimized bridges constructed according to the present teachings are relatively safe in various environments including those that may be subject to periodic earth quakes and other disruptive natural phenomenon.

Yet one other object is to provide a relatively inexpensive bridge system. Because most span movement is horizontal relatively small motors can be used to move spans on rollers as opposed to lifting the spans.

One other object is to provide a bridge where, when a span is open, the open space can accommodate passage of any vessel there below. To this end the present design has no components that remain above the open space after a span is moved.

Consistent with the above objects and advantages, the present invention includes a bridge assembly comprising first, second and third adjacent piers, the first and second piers defining a first space there between and the second and third piers defining a second space there between, third and fourth spaces above the first and second spaces, respectively, a first bridge span positionable so as to traverse the distance between the first and second piers within the third space, a second bridge span positionable so as to traverse the distance between the second and third piers within the fourth space, a first motivator linked to the first bridge span for moving the first span into and out of the third space and a second motivator linked to the second bridge span for moving at least a portion of the second bridge span from the fourth space to the third space so that at least a portion of the fourth space is unobstructed.

In some embodiments the invention further includes at least one intermediate pier between the second and third piers, the space between the intermediate and third piers being a fifth space, the space above the fifth space being an openable space, the openable space being the portion of the fourth space that is unobstructed when the portion of the second bridge span is moved to the third space. In some cases the first, second, third and intermediate piers are essentially equi-spaced.

In some embodiments roller members are provided between the tops of the piers and the spans thereabove. The rollers may be mounted to the tops of the piers.

In several embodiments the first span has a span width, each of the first and second piers has a pier width that is substantially twice as wide as the span width, first and second in-line sections of the first and second piers, respectively, aligned with the third pier and defining an in-line space, a supporting space above the in-line space, first and second lateral sections of the first and second piers laterally adjacent the first and second in-line sections, respectively, the lateral sections defining a lateral space there between, a receiving space above the lateral space, the first motivator for moving the first span between the supporting space and the receiving space.

In some embodiments the first and second in-line sections and first and second lateral sections comprise one lateral load bearing element and the first span comprises another lateral load bearing element and the assembly further includes a first track mounted to a first one of the lateral load bearing elements and rollers mounted to the second of the lateral load bearing elements, the rollers supportable on the track to facilitate rolling of the first span between the supporting and receiving spaces. Here, the track may be secured to the first span and the rollers may be secured to the tops of the piers.

The assembly may further include an intermediate pier between the second and third piers wherein the second and intermediate piers comprise a longitudinal load bearing element and the second span comprises another longitudinal load bearing element and, wherein, the assembly further includes a second track mounted to a first one of the longitudinal load bearing elements and rollers mounted to the second of the longitudinal load bearing elements, the rollers supportable on the track to facilitate rolling of the second span such that the at least one section moves between the fourth space and the supporting space. The longitudinal load bearing element that includes the second and fourth piers may also includes the first pier.

In some embodiments the first motivator moves the first span between the third space and a space above the third space. In other embodiments the first motivator moves the first span between the third space and the first space.

The second span may include first and second ends, a top and a bottom, the second end adjacent the third pier when the second span is in the fourth space, the assembly further including first and second aligning apparatus at the second end and the top of the third pier, respectively, the second aligning apparatus receiving the first aligning apparatus when the second span is moved into the fourth space so as to align the second span with the third pier. The first aligning apparatus may include a first inclined surface. Similarly, the second aligning apparatus may include a second inclined surface. In addition, the second aligning apparatus may include a guiding roller.

Another embodiment of the invention includes a method for opening a section of a bridge where the bridge includes several spans that are longitudinally arranged along the length of the bridge including at least first and second adjacent spans that, when the bridge is closed, occupy first and second spaces, respectively, the method comprising the steps of moving the first bridge span from the first space, moving at least a segment of the second bridge span from the second space into the first space so that at least a portion of the second space is unobstructed.

According to one embodiment, when the first span is in the first space and the second span is in the second space the first and second spans are aligned longitudinally and, the step of moving the first bridge span includes moving the first span from the first space laterally and wherein the step of moving the second span includes moving the second span longitudinally. In another embodiment, the step of moving the first bridge span includes moving the first span upward and out of the first space.

In yet another embodiment the invention includes a bridge assembly comprising first, second and third adjacent piers, each of the second and third piers including an in-line section and an adjacent lateral section, the in-line sections aligned along a longitudinal axis and the lateral sections aligned along a lateral axis that is essentially parallel to the longitudinal axis, the first pier and second pier in-line section defining a first in-line space there between, the second and third pier in-line sections defining a second in-line space there between, a space adjacent the first in-line space and the second lateral section defining a first lateral space, the second and third lateral sections defining a second lateral space there between, third and fourth in-line spaces above the first and second in-line spaces, respectively, and third and fourth lateral spaces above the first and second lateral spaces, respectively, a first bridge span positioned so as to traverse the distance between the first and second piers within the third in-line space, a second bridge span positionable so as to traverse the distance between the second and third piers within the fourth in-line space, a first motivator linkable to the second bridge span for moving the second span between the fourth in-line space and the fourth lateral space and a second motivator linkable to the second bridge span for moving at least a portion of the second bridge span from the fourth lateral space to the third lateral space so that at least a portion of the fourth lateral space is unobstructed.

Here the assembly may further include at least one intermediate pier between the second and third lateral pier sections, the space between the intermediate and third lateral section being a fifth space, the space above the fifth space being an openable space, the openable space being the portion of the fourth lateral space that is unobstructed when the portion of the second bridge span is moved to the third lateral space. The first lateral section, second lateral section, third lateral section and intermediate pier may be essentially equi-spaced.

The invention further includes a method for opening a section of a bridge where the bridge includes at least first and second adjacent spans that are longitudinally alignable along the length of the bridge and are supported by at least first, second and third piers, each pier including an in-line section and a lateral section laterally positioned with respect to the in-line section, the space between the first and second in-line pier sections being a first in-line space, the space between the second and third in-line pier sections being a second in-line space, the space above the first and second in-line spaces being a third in-line space and the space above the second in-line space being a fourth in-line space, the space between the first and second lateral pier sections being a first lateral space, the space between the second and third lateral pier sections being a second lateral space, the space above the first lateral space being a third lateral space and the space above the second lateral space being a fourth lateral space, when the bridge is closed, the first and second spans occupying the third and fourth in-line spaces, respectively, the method comprising the steps of: moving the second bridge span laterally from the fourth in-line space to the fourth lateral space and moving at least a segment of the second bridge span from the fourth lateral space into the third lateral space so that at least a portion of the fourth space and a portion of the fourth lateral space are unobstructed.

These and other objects, advantages and aspects of the invention will become apparent from the following description. In the description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown a preferred embodiment of the invention. Such embodiment does not necessarily represent the full scope of the invention and reference is made therefor, to the claims herein for interpreting the scope of the invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIGS. 1

a

through

1

d

are schematic diagrams illustrating a first embodiment to the present invention;

FIG. 2

is a cross-sectional view taken along the line

2

—

2

of

FIG. 1

c;

FIG. 3

is a cross-sectional view taken along the line

3

—

3

of

FIG. 1

b;

FIG. 4

is a schematic view taken along the line

4

—

4

of

FIG. 3

;

FIGS. 5

a

through

5

c

are schematic views of a second embodiment of the present invention;

FIG. 6

is a schematic cross-sectional view taken along the line

6

—

6

of

FIG. 5

a;

FIG. 7

is a schematic cross-sectional view taken along the line

7

—

7

of

FIG. 5

a;

FIGS. 8

a

through

8

c

are schematic diagrams illustrating a third embodiment of the present invention;

FIG. 9

is a cross-sectional view taken along the line

9

—

9

of

FIG. 8

a;

FIG. 10

is similar to

FIG. 9

, albeit illustrating an extended shaft and a raised span;

FIG. 11

is a plan view of the assembly of

FIG. 5

b

taken along the line

11

—

11

;

FIG. 12

is a plan view of the assembly of

FIG. 5

b

taken along the line

12

—

12

;

FIG. 13

is a view similar to

FIG. 11

, albeit with a bridge span in a different position and retracted lifts; and

FIG. 14

is a view similar to

FIG. 12

, albeit with a bridge span in a different position and retracted lifts.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings wherein like reference numerals represent similar elements throughout the several views and, more specifically, referring to

FIGS. 1

a

through

1

d,

a first embodiment of the present invention will be described in the context of a mechanical bridge

10

including a plurality of piers

9

,

12

,

14

,

16

and

18

(only five illustrated) that begins at a first shore

20

and traverses over a river

22

to a shore (not illustrated) opposite shore

20

. Piers

9

,

12

,

14

,

16

and

18

are equi-spaced so as to equally accept load from traffic passing across the bridge thereabove. In addition to piers

9

,

12

,

14

,

16

and

18

, bridge

10

also includes a plurality of spans or bridge sections

24

,

26

,

28

and

32

that traverse the distance between the tops of piers

9

,

12

,

14

,

16

and

18

and provide a deck

34

above river

22

for vehicular travel. Spans

24

,

26

and

32

have essentially identical lengths and traverse the distance between the tops of two adjacent piers. For example, span

26

traverses the distance between the tops of piers

12

and

14

. One special and relatively long span

28

traverses the distance between the tops of three adjacent piers including piers

14

,

16

and

18

. Thus, span

28

is twice as long as any of the other spans in bridge configuration

10

.

Referring specifically to

FIG. 1

b,

piers

12

and

14

are approximately twice as wide as the other piers that make up bridge

10

. To this end, pier

12

includes an in-line section

38

that is, as the name implies, in-line with other piers (e.g.,

16

,

18

, etc.) that form the bridge and a lateral section

40

that is laterally positioned with respect to in-line section

38

. Similarly, pier

14

includes an in-line section

42

and a lateral section

44

. Lateral sections

40

and

44

are aligned to the same side of the in-line sections

38

and

42

and are capable of supporting a bridge span thereabove.

For the purpose of explaining this first embodiment of the invention it is advantageous to define the illustrated piers in a specific manner and also to define various spaces with respect to those piers. To this end, referring still to

FIGS. 1

a

through

1

d

and also to

FIG. 1

e,

piers

12

,

14

and

18

will generally be referred to as first, second and third piers, pier

16

will be referred to as an intermediate pier, the space

48

between piers

12

and

14

will be referred to as a first space, the space

50

between piers

14

and

18

will be referred to as a second space, the space above first space

48

and, in

FIG. 1

a

occupied by span

26

, will be referred to as a third space

52

, the space above second space

50

and, in

FIG. 1

a,

occupied by span

28

, will be referred to as a fourth space

54

, the space between in-line pier sections

38

and

42

will be referred to as an in-line space

41

, the space above in-line space

41

will be referred to as a supporting space

43

, the space between lateral pier sections

40

and

44

will be referred to as a lateral space

45

and the space above lateral space

45

will be referred to as a storage space

47

. In addition, end

64

of span

28

will be referred to as a leading end

64

. In addition, the space between piers

16

and

18

will be referred to as a fifth space

56

and the space thereabove which in

FIG. 1

a

is occupied by a portion of span

28

will be referred to as an opening space

58

.

With the spaces and piers as defined above and referring to

FIGS. 1

a

through

1

e,

according to this first embodiment of the invention, a section of bridge

10

can be opened to allow river bound traffic to pass through the open section. To this end, according to a first step in the process of clearing a passage through bridge

10

for river bound traffic, first span

26

is removed from supporting space

43

. This is accomplished by moving first span

26

laterally from supporting space

43

to storage space

47

so that lateral sections

40

and

44

of piers

12

and

14

, respectively, support span

26

. This condition is illustrated in

FIG. 1

c.

Next, second span

28

is moved longitudinally along the tops of the in-line piers and pier sections so that at least a portion of span

28

is positioned within supporting space

43

. When span

28

is moved in this manner, an opening is created between spans

28

and

32

. By moving span

28

as far as possible into supporting space

43

so that approximately half of span

28

is within space

52

, the entire opening space

58

is rendered unobstructed so that river bound traffic can pass therethrough.

To close the bridge

10

, the above described process is simply reversed. To this end, a first step in closing the open space

58

is to drive span

28

toward span

32

until leading end

64

of span

28

is received and supported on the top of pier

18

. Next, span

26

can be moved form it's lateral position illustrated in

FIG. 1

d

to its in-line position as illustrated in

FIG. 1

b

where span

26

traverses the distance between and is support by adjacent in-line pier sections

38

and

42

.

Referring now to

FIGS. 1

b

and

2

, the mechanism used to slide or move span

26

from the supporting space

43

to the storage space

47

will be described in more detail. To this end, the tops of piers

12

and

14

comprise a first lateral load bearing element while the underside of span

26

comprises a second lateral load bearing element. Rollers are provided on one of the lateral load bearing elements while one or more tracks are provided on the other of the lateral load bearing elements. The rollers and tracks cooperate to facilitate lateral movement of span

26

. Similarly, the tops of piers

14

and

16

comprise a first longitudinal load bearing element and the underside of span

28

comprises a second longitudinal load bearing element. Rollers are provided on one of the longitudinal load bearing elements while one or more tracks are provided on the other of the longitudinal load bearing elements. The rollers and tracks on the longitudinal elements cooperate to facilitate longitudinal movement of span

28

. Specifically, at the tops of each pier

12

and

14

, rollers are provided that facilitate easy movement of span

26

between the supporting space

43

and the storage space

47

. The rollers in this embodiment are identical at the tops of piers

12

and

14

and therefore, only the rollers corresponding to the top of pier

12

will be described in detail. The configuration at the top of pier

12

includes a timber

70

, a pier cap

72

, a first motivator

74

and the first span

26

. Timber

70

includes a lower end (not illustrated) that extends down through the river (see

14

in

FIG. 1

a

) and is embedded in the bottom of the river and a top end

76

. Pier cap

72

is a concrete member and is formed about the top end

76

of timber

70

. Although not illustrated in

FIG. 2

, a plurality of timbers adjacent timber

70

are provided that support cap

72

and the other bridge components thereabove.

Cap

72

forms three roller housings

78

,

80

and

82

that generally face upward. A central roller housing

80

includes a plurality of rollers

84

that form an upward facing roller surface

86

for supporting span

26

thereabove. Lateral roller housings

78

and

82

each support a plurality of rollers

88

,

90

, respectively, that form support surfaces

92

and

94

for guiding and supporting span

26

thereabove.

Surfaces

92

and

94

are tilted in a direction toward central roller housing

80

and therefore restrict movement of span

26

in other than the direction between supporting space

43

and storage space

47

.

Motivator

74

is a motor and is securely mounted to a side

98

of cap

72

(see also

FIGS. 1

b

through

1

d

in this regard). Motor

74

includes a shaft

96

that extends up above cap

72

. At the distal end of shaft

96

a large gear having vertically aligned teeth is mounted.

Span

26

includes a bottom support

104

and various components that form a top support

106

that will be described in more detail below. Bottom support

104

is preferably formed of concrete and has a top surface

102

and a bottom surface

105

. Top surface

102

is essentially flat and provides a support deck for components

106

thereabove. Bottom surface

106

forms three separate roller recesses

108

,

110

and

112

that form roller surfaces

114

,

116

and

118

, respectively. A central roller surface

116

faces downward and is sized so as to receive surface

86

of rollers

84

thereon. Similarly, roller surfaces

114

and

118

are sized and configured so as to receive rollers

88

and

90

, respectively, corresponding to the lateral rollers as illustrated.

A lateral edge

120

of span

26

forms a gear receiving surface having teeth sized to receive the teeth of gear

100

. Edge

120

extends so that the teeth of gear

100

are received within the teeth of edge

120

. While structure

104

is illustrated and described above as being formed of concrete, it should be appreciated that certain of the features may be formed of other more suitable materials used for specialized purpose. For instance, a steel member may be mounted to member

104

that forms the teeth

120

that cooperate with motor

74

to move span

26

. Similarly, flat steel plates may be provided on the surfaces of each of roller surfaces

114

,

116

and

118

that may be greased to facilitate easy movement of rollers there along.

While only a single roller system is illustrated in

FIG. 2

, it should be appreciated that several roller systems like the one illustrated in

FIG. 2

may be provided at the top each of the first and second piers

12

,

14

, respectively. For instance, in one embodiment at least four roller assemblies would be equi-spaced along the top of each of piers

12

and

14

. It should also be appreciated that, because efficient roller systems reduce the amount of power required to move large objects, a relatively small motor

74

should be able to move a span

26

back and forth between the supporting space

43

and storage space

47

. To this end, to move span

26

, motor

74

is driven and applies a force to span

26

that drives the span

26

either into or out of the figure illustrated in FIG.

2

and therefore either toward or away from supporting space

43

(see also

FIGS. 1

c

and

1

e

).

While first span

26

remains fully supported during movement between supporting space

43

and storage space

47

, as illustrated in the

FIG. 1

sequence of drawings, second span

28

is not fully supported during movement between spans

12

and

18

. In other words, span

28

, at certain times during movement, is cantilevered about one or more piers so that at least segments of span

28

are out and over open spaces therebelow. For this reason, a relatively more complex roller system is contemplated to maintain span

28

in a stable configuration during movement. Referring now to

FIGS. 1

a

through

1

d

and also to

FIG. 3

, the components that are used to construct the top of pier

16

are illustrated. The components in

FIG. 3

include two timbers

130

,

132

, a pier cap

134

, a span lower structure

136

, a span upper structure

138

and a second motivator

140

. Timbers

130

and

132

both extend down to the bottom of the river bed to provide support. The top ends

142

and

144

of timbers

130

and

132

, respectively, extend into a lower surface of cap

134

. Cap

134

forms a plurality of roller housings that together cooperate to provide support span

16

and also to provide guidance to span

16

as span

16

is moved. Four roller housings are illustrated including housings

146

,

148

,

150

and

152

. A plurality of rollers

154

are mounted in housing

150

and form a support surface

156

that faces upward. Similarly, a plurality of rollers

158

are mounted in housing

152

and form a support surface

160

that faces upward. A plurality of rollers

162

are mounted in housing

148

and form a vertical guiding surface

164

. A plurality of rollers

166

are mounted in housing

146

and provide a downward facing restraining surface

168

. Other roller assemblies may be provided along the length of cap

134

to facilitate easy movement of span

16

thereabove. Motivator

140

is similar to the motivator

74

described with respect to FIG.

2

and therefore will not be described here in detail. Suffice it to say that a gear

170

extends from the motivator

140

and includes vertically aligned teeth that open, at least to one side, facing an edge

172

of lower structure

136

.

Lower structure

136

includes a top surface

173

for supporting upper structure

138

and a bottom surface

175

. Bottom surface

175

forms a plurality of recesses (e.g.,

174

,

176

) that are sized and positioned so as to receive upward facing rollers that are mounted within cap

134

. Thus, recess

174

forms a load bearing surface

180

that receives support surface

160

while recess

176

forms a load bearing surface

182

that receives support surface

156

. An upper portion of edge

172

contacts guidance surface

164

to restrain lateral movement of span

16

. Upper surface

173

forms an upward facing restraining surface

188

that contacts downward facing restraining surface

168

.

Upper structure

138

includes a plurality of I beams

190

that support a concrete road surface

192

thereabove. A guide rail

194

is provided along a lateral edge of member

192

. Referring also to

FIG. 2

, configuration of upper structures

106

and

138

is relatively unimportant with respect to what is believed to be novel and therefore are not explained here in detail. Suffice it to say structures

106

and

138

must be rigid and must be securely mounted to the top surfaces of lower structures

104

and

136

, respectively.

As in the case of the roller system illustrated in

FIG. 2

, the system illustrated in

FIG. 3

is only exemplary and a plurality of roller systems like the one illustrated in

FIG. 3

would likely be provided at various locations along the tops of piers

14

,

16

and

18

.

Referring now to

FIGS. 1

a

through

1

d

and also to

FIG. 4

, while span

28

is to be constructed of concrete and steel and other types of rigid materials and therefore should be extremely rigid, where the open space

58

is relatively large (e.g., 60-100 feet), while span

28

is being moved from its open position to the position where space

58

is closed, leading edge

64

may bow downward a small distance when span

28

is at its most extended point and just prior to support by pier

18

. For this reason, in an advantageous embodiment, a guiding mechanism is provided at the receiving edge of pier

18

for “lifting” the leading edge

64

. To this end, the underside

200

of leading edge

64

is sloped so that underside

200

can be used to guide span

28

upward when edge

64

reaches pier

18

. In addition, a guiding component

201

is attached to the bottom of cap

134

. Guiding component

201

extends longitudinally from the under surface of cap

134

and includes a sloped surface

202

that is effectively a mirror image of sloped surface

200

. In addition, a plurality of rollers

204

are provided on sloped surface

202

to reduce friction between surfaces

200

and

202

during reception of span

28

.

Referring now to

FIGS. 5

a

through

5

c,

a second embodiment of the invention is illustrated. This second embodiment, like the first embodiment, includes a plurality of piers

9

,

12

,

14

,

16

and

18

and a plurality of spans

24

,

26

,

28

and

32

that traverse the distance between the piers. Each of piers

9

and

12

have a width that is generally the same width as each of the spans (e.g.,

24

). Each of piers

14

,

16

and

18

, however, has a width that is approximately twice as wide as the width of any of the spans (e.g.,

28

). To this end, pier

14

includes an in-line section

250

that is in-line with piers

9

and

12

and a lateral section

252

that is laterally positioned with respect to in-line section

250

. Similarly, pier

16

includes an in-line section

254

and a lateral section

256

while pier

18

includes an in-line section

258

and a lateral section

260

.

Referring now to

FIGS. 1

a

and

5

a

through

5

c,

as above, in order to understand the second embodiment, it is advantageous to define specific piers by specific names and specific spaces with respect to those piers by specific names. To this end, piers

12

,

14

and

18

are referred to generally as first, second and third piers, while pier

16

is referred to as an intermediate pier. In

FIG. 1

a,

the space between piers

12

and

14

is referred to as a first in-line space, the space

50

between piers

14

and

18

is referred to as a second in-line space, the space above first in-line space

48

is referred to as a third in-line space

52

and the space

54

above second in-line space

50

is referred to as a fourth in-line space

54

. The in-line spaces are aligned along a longitudinal axis

27

.

In addition, referring to

FIGS. 1

a,

5

a

and

6

, the space that is adjacent each of first in-line space

48

and lateral pier section

252

is referred to as a first lateral space

270

and the space above first lateral space

270

is referred to as a third lateral space

272

. Referring to

FIGS. 1

a,

5

a

and

7

, the space between lateral pier sections

252

and

260

is referred to as second lateral space

274

, the space thereabove is referred to as fourth lateral space

276

, the space between intermediate pier

256

and lateral section

260

is referred to as a fifth space and the space above the fifth space is referred to as an openable space. The lateral spaces are aligned along a lateral axis

290

.

With the piers and spaces defined above, operation of the bridge illustrated in

FIGS. 5

a

through

5

c

can be easily understood. Referring still to

FIGS. 5

a

through

5

c

and also to

FIGS. 6 and 7

, initially, to facilitate vehicular traffic over the bridge, second span

28

is in the fourth in-line space

54

(see FIG.

7

). To open the bridge and allow water bound traffic to pass therethrough, first, span

28

is moved from the fourth in-line space

54

laterally to the fourth lateral space

276

so that span

28

is supported on the tops of lateral sections

252

,

256

and

260

of piers

14

,

16

and

18

as illustrated in

FIG. 5

b.

Next, span

28

is moved longitudinally along the lateral axis

290

to the left as illustrated in

FIG. 5

b

until a segment (i.e., the lefthand half of span

28

referred to as the “openable space” above) is positioned within third lateral space

272

as illustrated in

FIG. 5

c.

After this second move, an open space

300

is formed between piers

16

and

18

to allow water bound traffic to pass therethrough unobstructed.

To reclose the bridge, the process as described above is reversed. To this end, span

28

is first moved to the right as illustrated in

FIG. 5

c

until the entire span

28

is within fourth lateral space

276

. Then span

28

is moved laterally back into space

54

above the in-line sections of piers

14

,

16

and

18

.

The movement systems used in the second embodiment would be similar to those used in the first embodiment including motivators, roller assemblies and tracks, and should be configurable by one of ordinary still in the art. Nevertheless, it should be appreciated that while this embodiment is contemplated, in some ways, this embodiment is less preferred than the first embodiment because the movement system mechanics would be more complex. This is because the movement mechanics have to facilitate movement of span

28

in two separate directions (i.e., laterally and then longitudinally). In addition to the motivators for span movement laterally and longitudinally, this design would also likely require some other moveable components.

Referring now to

FIGS. 5

a,

11

and

12

, exemplary movement assemblies at the tops of piers

14

and

18

are illustrated. Specifically, the assemblies illustrated are located at the tops of lateral pier sections

252

and

260

. Pier

14

includes timbers

450

and

452

, a pier cap

454

, several lateral roller assemblies

456

(only one illustrated), a hydraulic lift

451

for each lateral roller assembly, a span assembly

28

and at least two longitudinal roller assemblies

458

and

460

. From the first embodiment description above the functions, configurations and operation of most of the components of

FIGS. 11 and 12

should be understood and therefore will not be explained again here in detail.

Hydraulic lift

451

is mounted on a top surface of cap

454

and includes an upwardly extending shaft

462

. Roller assembly

456

is mounted at the top end of shaft

462

. Lift

451

is capable of changing the vertical elevation of roller assembly

456

and other span components (e.g.,

28

) thereabove.

Referring to

FIGS. 5

a,

11

,

12

and

2

, the lateral roller assemblies at the tops of in-line pier sections

250

,

254

and

258

need not include hydraulic lifts (e.g.,

451

) and therefore are more akin to the assemblies illustrated in FIG.

2

. In their highest position (i.e., with corresponding hydraulic lifts

451

extended to a maximum point), the rollers of assemblies

451

would be at the same vertical height as, and would be aligned with, the stationary roller assemblies on the in-line pier sections

250

,

254

and

258

. Thus, at their lowest position (i.e., with lifts

451

retracted), the rollers of assemblies

451

would be below the stationary rollers at a lowest level (see also FIGS.

13

and

14

).

Referring again to

FIGS. 11 and 12

, longitudinal roller assembly

458

extends up from cap

454

at a lateral end of cap

454

and forms a receiving bay

470

designed to receive a lateral edge

472

of span

28

. To this end upper and lower roller banks

474

and

476

, respectively, are provided in bay

470

for supporting edge

472

. The space D

1

between roller banks

474

and

476

is slightly greater than the width D

2

of end

472

. The second longitudinal roller assembly

460

includes a single upward facing roller bank

461

on a side of hydraulic lift

451

opposite assembly

458

. Importantly, as best seen in

FIG. 12

, cap

454

extends longitudinally past an adjacent end

449

of span

28

on a side of lift

451

opposite pier

18

.

Referring to

FIGS. 12 and 14

, upward facing roller banks

461

and

476

are at the same vertical height which is slightly higher than the top of roller assemblies

451

when those assemblies

451

are in their lower positions.

Referring to

FIGS. 5

a

and

12

, the components at the top of lateral pier section

260

are similar to the components at the top of section

252

with a few exceptions. Similarities include a supporting timber

490

, a pier cap

482

, a hydraulic lift

492

and several (only one shown) lateral roller assemblies

494

. A first distinction is that only a single roller assembly

480

is provided at the top of pier cap

482

on the same side of lift

492

as pier

14

. Assembly

480

includes a roller bank

421

that defines an upward facing support surface

423

. The height of surface

423

is identical to the heights of surfaces

460

and

467

and is slightly higher than the tops of assemblies

494

when assemblies

494

are in their lowest positions. On the side of lift

492

opposite roller assembly

480

, span

32

rests on, and is securely mounted to, the top of pier

18

.

Referring still to

FIGS. 11 and 12

, span

26

forms an under surface

498

that defines downwardly extending track members

500

and

502

. Each track member

500

,

502

is shaped so as to be received and supported by roller assemblies

451

and

494

there below and thus extend laterally across span

28

. Track members

500

and

502

do not extend completely across span

28

, but rather stop short of end

472

. This is so that end

472

can be received within bay

470

.

In operation, to open the bridge, referring to

FIGS. 11 through 14

, with span

28

in the in-line position (see

FIG. 5

a

) and lifts

451

and

492

extended, a motivator (not illustrated), drives span

28

laterally in direction

508

on roller assemblies

456

and

494

into a position supported above lateral pier sections

252

,

256

and

268

. An intermediate span position is illustrated in FIG.

11

. The motivator continues to drive span

28

until end

472

is aligned with but longitudinally displaced from bay

470

as illustrated in

FIGS. 5

b

and

12

. Next, lifts

451

and

492

are lowered. When lifts

451

and

492

are lowered, span

28

comes to rest and be supported on the upward facing roller bank surfaces

467

and

423

. Span

28

supported by roller assemblies

461

and

421

is illustrated in FIG.

14

. Note that lifts

451

and

492

need only be lowered a very small amount and therefore span

28

is only lowered very slightly.

Continuing, referring to

FIG. 14

, the second motivator (not illustrated) drives span

28

longitudinally in the direction indicated by arrow

510

. As span

28

is driven longitudinally, end

449

is received within bay

470

and is supported and restrained by roller assemblies

474

and

476

. Referring specifically to

FIG. 14

, roller assembly

458

should be positioned relative to assembly

480

such that span end

449

is fully received between banks

474

and

476

prior to opposite span end

447

coming off roller bank

421

. This ensures that end

447

will be supported in a cantilevered manner upon becoming unsupported.

The second motivator continues to drive span

28

in the direction of arrow

510

until span

28

is in the position illustrated in

FIG. 5

c

where space

300

is completely open for river bound travel.

To close space

300

and facilitate vehicular travel, span

28

is driven from its location in

FIG. 5

c

to the location in

FIG. 5

b

while being supported on longitudinal roller assemblies

458

,

460

,

480

, etc. Next, lifts

451

and

492

are extended to lift span

28

up and above longitudinal assemblies

460

and

480

and so that span

28

is supported by lateral assemblies

456

and

494

. Continuing span

28

is driven from the position in

FIG. 5

b

to the position in

FIG. 5

a.

Importantly, when span

28

is in the in-line position (see

FIG. 5

a

), span

28

is fully supported by rigid mechanical rollers as opposed to hydraulic lifts. This makes for a more resilient bridge system.

Referring now to

FIGS. 8

a

through

8

c,

a third embodiment of the present invention will be described in the context of a bridge

330

that includes a plurality of piers

9

,

12

,

14

,

16

and

18

. In addition, bridge

330

includes spans

24

,

26

,

28

and

32

that traversing a distances between the piers, each of spans

24

,

26

and

32

traversing a distance between adjacent piers and span

28

being approximately twice as long as the other spans, traversing a distance between piers

14

,

16

and

18

.

To understand this third embodiment, as with the embodiments described above, it is helpful to specifically label several of the piers and the spaces relative thereto. To this end, piers

12

,

14

and

18

are referred to as first, second and third piers, respectively, pier

16

is referred to as an intermediate pier, the space between piers

12

and

14

is referred to as a first space

333

, the space between piers

14

and

18

is referred to as a second space, the space above the first space is referred to as a third space

336

, and the space above second space

334

is referred to as a fourth space

338

. Third space

336

is approximately the same size as span

26

and the space thereabove is referred to as a fifth space

340

.

In operation, to open a section of bridge

330

, first, with span

26

supported between piers

12

and

14

and within third space

336

, first span

26

is raised up and into fifth space

340

thereabove. After this move, the bridge is in the configuration illustrated in

FIG. 8

b.

Next, span

28

is moved from fourth space

338

toward third space

336

such that a segment [e.g., approximately the left half of span

28

as illustrated] of span

28

moves into third space

336

. After this move, bridge

330

is configured as illustrated in

FIG. 8

c

with a leading end

350

of second span

28

supported on the top of pier

16

. In this configuration, the space between and above piers

16

and

18

is completely unobstructed and water bound traffic can pass there through.

To reclose bridge

300

, the method described above is simply reversed. To this end, span

28

is moved toward span

32

until leading end

350

contacts and is supported by the top of span

18

. This configuration is illustrated

FIG. 8

b.

Next, span

26

is lowered until that span is supported on the tops of piers

12

and

14

as illustrated in

FIG. 8

a.

Referring now to

FIGS. 8

a

and

9

, in order to raise and lower span

26

, the components illustrated in

FIG. 9

are provided at each end at each of piers

12

and

14

. Because the components at each end of each of piers

12

and

14

are generally the same, only the components provided at one end of pier

12

are illustrated. The components at pier

12

include a timber

370

, a lower construct

374

, an upper construct

376

and a motivator

378

. Timber

370

has a lower end (not illustrated) that extends down to the bottom of the river and an upper end

380

that is received by and supports cap

372

. As above, other timbers would also be provided to support cap

372

. Cap

372

forms an upper surface

382

that is essentially flat. Motivator

378

is mounted to cap

372

in any manner known in the art. Motivator

378

is simply a lifting mechanism including a hydraulic motor of some type and a shaft

390

that extends upwardly therefrom. A distall end

392

of shaft

390

can be raised and lowered in a manner explained in more detail below.

Referring still to

FIG. 9

, lower structure

374

includes a concrete base member

394

and a stopper member

396

that extends downward therefrom. One or more other stopper members

396

(not illustrated) would be provided along the length of member

394

to support that member above surface

382

.

Upper structure

376

includes a plurality of eye beams

398

that form a lattice and support a deck

400

thereabove. Deck

400

forms top and bottom surfaces

402

and

404

, respectively. The lattice formed by beams

398

contact under surface

404

. In addition, distall end

392

of shaft

390

contacts under surface

404

. Surface

402

provides a driving deck for vehicular traffic.

Referring now to

FIGS. 9 and 10

, the components of

FIG. 9

are shown in

FIG. 10

in a raised position where shaft

390

has been extended to raise both the upper and lower structures

376

and

374

, respectively. Once raised, a space

410

is provided between span

26

and surface

382

. Referring also to

FIG. 8

b

and

FIG. 8

c,

once span

26

is raised as illustrated in

FIG. 10

, span

28

is rolled into space

410

. The support rolling structure used to roll span

28

is similar to the structure illustrated in FIG.

3

.

It should be understood that the methods and apparatuses described above are only exemplary and do not limit the scope of the invention, and that various modifications could be made by those skilled in the art that would fall under the scope of the invention. For example, while the embodiments above include roller assemblies mounted to the tops of piers, other embodiments may include roller assemblies mounted to the undersides of spans. In addition, referring to

FIGS. 8

a

-

8

c,

instead of moving span

26

upward, span

26

may be lowered to provide a space for span

28

. Moreover, referring to

FIGS. 5

a

-

5

c

and

11

through

14

, while that embodiment shows span

28

being vertically repositioned between lateral and longitudinal moves, in other embodiments rollers may be raised and lowered so that the vertical span position remains essentially constant. Furthermore, while two motivators are described above, it should be appreciated that some embodiments may require only a single motivator. In addition, embodiments with additional vertical restraints are contemplated.

To apprise the public of the scope of this invention, the following claims are made:

Number	Name	Date	Kind
94529	Trowbridge	Sep 1869	A
514754	Jessup	Feb 1894	A
535831	Jessup	Mar 1895	A
598012	Sampson	Jan 1898	A
617201	Strobel	Jan 1899	A
663484	Bevans	Dec 1900	A
1619678	Prinz	Mar 1927	A
3668729	Mori et al.	Jun 1972	A
4907312	Yang et al.	Mar 1990	A

Mechanical bridge assembly and method

Information

Patent Number

Date Filed

Date Issued

Inventors

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Term Extension

Abstract

Description

Claims

US Referenced Citations (9)

Foreign Referenced Citations (1)