US3864777A

US3864777A - Bridge-operating machinery

Info

Publication number: US3864777A
Application number: US465099A
Authority: US
Inventors: George Perkons; Orrell B Schailey
Original assignee: EARLE GEAR AND MACHINE CO
Current assignee: EARLE INDUSTRIES Inc A CORP OF
Priority date: 1974-04-29
Filing date: 1974-04-29
Publication date: 1975-02-11
Anticipated expiration: 1992-02-11

Abstract

Bridge-operating machinery, for rack-driven bascule spans, comprises heavy-duty gear-drive means connected to drive the racks and swing the span. A pair of counterpart, inverted, enclosed bridge-drive units (preferably incorporating speedreducer mechanisms) coupled to motor-driven shafting actuated through a differential drive delivers power to the racks; and each such bridge-drive unit includes parallel input, intermediate, and output shafts disposed with their axes in an irregular triangular array, with rigid, sealed structure mounting the shafts of each mechanism as a unitary assembly. Each of two, heavy, opposing walls of the housing structure is provided with three bearing-carrying openings, corresponding to the said array, which confront similar openings in the opposite wall; and shaft, and the gear means carried thereby, is journaled within one set of confronting openings in protected position within the housing structure, and with a drive pinion of each output shaft disposed exteriorly of its housing structure in engagement with a rack. The housing structure has mounting means adapting the unit for mounting in a variety of different positions, and location in such different positions, of each unitary drive assembly, with its irregular triangular array of gear-carrying shafts housed therein, adapts the mechanism for use in quite different bridge installations. Lubrication, protection, proper alignment, and ease of inspection and maintenance of the moving parts is assured.

Description

Perkons et a1.

[ BRIDGE-OPERATING MACHINERY [75] Inventors: George Perkons; Orrell B. Schailey,

both of Philadelphia, Pa.

[73] Assignee: The Earle Gear and Machine Company, Philadelphia, Pa.

[22] Filed: Apr. 29, 1974 [21] Appl. No.: 465,099

[52] U.S. Cl. 14/38 [51] Int. Cl. E0ld 15/08 [58] Field of Search 14/38, 40, 37, 39, 41

[56] References Cited UNlTED STATES PATENTS 708,348 9/1902 Hall 14/40 719,153 [/1903 Smettcrs.... 14/40 1,659,250 2/1928 Erdal 14/41 FOREIGN PATENTS OR APPLICATIONS 595,733 10/1925 France 14/40 901,424 l/l954 Germany l4/38 Primary Examiner-Nile C. Byers, Jr. Attorney, Agent, or Firm-Synnestvedt & Lechner [57] ABSTRACT Feb. 11, 1975 nected to drive the racks and swing the span. A pair of counterpart, inverted, enclosed bridge-drive units (preferably incorporating speed-reducer mechanisms) coupled to motor-driven shafting actuated through a differential drive delivers power to the racks; and each such bridge-drive unit includes parallel input. intermediate, and output shafts disposed with their axes in an irregular triangular array, with rigid. sealed structure mounting the shafts of each mechanism as a unitary assembly. Each of two, heavy, opposing walls of the housing structure is provided with three bearingcarrying openings, corresponding to the said array, which confront similar openings in the opposite wall; and shaft, and the gear means carried thereby, is journaled within one set of confronting openings in protected position within the housing structure, and with a drive pinion of each output shaft disposed exteriorly of its housing structure in engagement with a rack. The housing structure has mounting means adapting the unit for mounting in a variety of different positions, and location in such different positions, of each unitary drive assembly, with its irregular triangular array of gear-carrying shafts housed therein, adapts the mechanism for use in quite different bridge installations. Lubrication, protection, proper alignment, and ease of inspection and maintenance of the moving parts is assured.

19 Claims, 9 Drawing Figures PATENTEUFEB' 3.864.777

SHEET 10F 6 PATENTEDFEB 3.864.777

SHEET 2 BF 6 AMA PATENTEB FEB] 1 I975 SHEET 3 0F 6 BRIDGE-OPERATING MACHINERY BACKGROUND OF THE INVENTION This invention is concerned with bridge-operating machinery for movable span bridges, particularly bridges of either single or double-leaf bascule type, in which the span, or leaf, pivots about a horizontal axis in swinging to and from open position.

Bridges of this kind, while widely used, have been subject to installation and maintenance problems. Many of these arise from the hostile environment in which the several sets of open gearing, which characterize the prior art, are required to operate. These problems have been aggravated in recent years, as will be appreciated when it is realized that a bridge which, years ago, might have been opened and shut perhaps only forty or fifty times in a year (or, at most, a few hundred times), today may be subjected to thousands of operations per year, because of the vast increase in boating activity, on the one hand, and the high level of vehicular use of the bridge, on the other hand.

With more particular reference to installation problems, alignment requirements of the drive gearing have been severe, due to the many individual and separate shafts, bearings and gears which it was necessary to hold in close locational tolerance, to ensure proper relationships and tolerances throughout the drive train. In addition, since such equipment is used near bodies of water, frequently salt water, it is subjected to the adverse effects of the elements, with severe rust and corrosion and resultant high maintenance. Substantial maintenance problems also have resulted from the presence, in the exposed machinery, of abrasive foreign material, such as sand, and various types of dirt and litter, including the accumulation of drippings from automobiles, droppings from pigeons and seagulls, and the like. Furthermore, many detailed design differences have been required in adapting the bridge-operating machinery to different bridges.

In summary, the machinery previously available has not been fully satisfactory because of installation, cleaning, and lubrication problems, and because of the frequent necessity to repair and/or replace and/or realign worn or damaged parts, and the lack of ready adaptability to differing environmental bridge structures.

SUMMARY OF THE INVENTION It is the general objective of this invention to overcome the aforesaid problems by provision of improved bascule bridge assemblies, and particularly improved gear-drive apparatus, adaptable to different installations, which apparatus is very simple to install and requires a minimum of maintenance. Specifically, the improved apparatus assures proper lubrication, and exclusion of dirt, water, sand and other foreign material from the gears, and, accordingly, the apparatus is of improved reliability, while at the same time the sealed units of this invention are versatile as to different installations.

In achievement of these general objectives, the invention provides novel, unitary, sealed gear-drive units (usually including reduction gearing), in place of the open gearing previously employed; while at the same time these units are configured to be readily adaptable for use in bridges of different designs, and may thus be substituted for the open-gear trains of a variety of existing installations. This flexibility, of course, imposes the requirement that apparatus embodying the invention be capable of accommodating different positions of the input, or primary, shaft, and/or of the output shaft which drives the bridge-carried rack. To meet this requirement in a simple and effective way, the invention utilizes input, intermediate, and output shafts disposed in an irregular triangular, parallel relation in novel combination with a housing structure which includes spaced, parallel walls, apertured to receive and mount the shafts, and versatile mounting means for the housing itself. The housing, with its shafts and gearing, constitutes a sealed unit which eliminates a number of intermediate, exposed bearings, bearing pedestals, and pillow blocks previously utilized in bridge installations. Also, and importantly, the novel apparatus makes it possible, whenever desired, to eliminate the outboard bearing previously required at the rack-driving pinion.

It is a feature that these units may be bodily shifted, vertically and/or horizontally, and also rotated to, and installed in, different positions in which the input and- /or output shafts in one installation reside in different vertical and horizontal planes than those planes which they would occupy in another installation, so as to accommodate the mechanism to different bridge structurcs, different foundations, and different environmental conditions; and it is a further feature that in any of the various positions in which the unit may be mounted, the working parts are assured of proper lubrication, and protection from grit, dirt and corrosion, and are yet readily inspected, and, if necessary, easily adjusted, repaired, or replaced.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is a partly sectional and partly elevational view of a bascule bridge, illustrating the main central drive unit and the inverted counterpart right and lefthand improved bridge-drive units with their output drive pinions engaging the arcuate racks carried by the main girders of the bridge, which units in this embodiment include speed-reduction gearing;

FIG. 2 is an enlarged fragmentary end view, taken as indicated by the line 22 of FIG. 1, and showing one main girder of the bridge and its arcuate rack in full lines, in bridge-closed position, and in broken lines in bridge-open position;

FIG. 3 is a partly sectional and partly elevational view of one of the sealed bridge-drive units, the view being taken as indicated by the line 33 of FIG. 4;

FIG. 4 is a sectional plan view of the bridge-drive unit, the view being taken as shown by line 4-4 of FIG.

FIG. 5 is a cross-sectional view taken on the line 5--5 of FIG. 3;

FIG. 6 is a cross-sectional view taken on the line 66 of FIG. 3;

FIG. 7 is a fragmentary, somewhat schematic, view of a different installation, in which the bridge-drive unit occupies a position which is rotated with respect to the position of the unit as illustrated in the embodiment of FIGS. 1 to 6;

FIG. 8 is a similar view, showing said unit mounted in an oblique position, as compared with the other two illustrated positions; and

FIG. 9 is a somewhat diagrammatic showing of the bridge-drive unit, partially modified, by the use of an adapter casing-element, so as to accommodate a differ- DETAILED DESCRIPTION OF THE INVENTION Although, generally, what is the righthand side of a bridge and what the lefthand side depends upon which way one is facing the bridge, in what follows the structure at the right of FIG. 1 will be considered as being at the righthand side of the bridge, while the structure at the left of that Figure will be considered as being at the lefthand side of the bridge.

With initial reference to FIG. I, there is illustrated the movable span, or Ieafl0, of a bascule bridge. The leaf, shown in section, is of known type and may comprise a roadbed 11 with longitudinal channel members 12, and with stringersor l-beams l3, and other structure including transverse members (not shown), all supported by right and left main, bascule girders l4 and 14a, and supplementary girders 16, 16a. Right and lefthand

trunnions

15, 15a are disposed in axial alignment and provide pivotal support for the leaf by virtue of pivotal mounting of the pair of main griders 14, 14a, and the pair of supplementary trunnion girders 16, 16a, upon the trunnions 15, a, as is known. to accommodate swinging movements of the span about the axis, a, defined by the trunnions, each trunnion is pivotally mounted within a trunnion bearing, enclosed within the housing 17, 17' (or 17a, 17a), the bearing housings being respectively carried by the bearing plates 18, 18a, on

pedestals

19, 19a.

The leaf 10 is swingable with respect to the fixed bridge structure, right and lefthand portions of which are shown at 20 and 20a. To accomplish this swinging movement, as is well illustrated in FIG. 2, each of the main bascule girders has rigidly secured thereto a rack (22 for the righthand girder l4 and 22a for the lefthand girder 14a) which rack is arcuately curved about the trunnion-defined axis a. As will be clear from FIGS. 1 and 2, the main girders l4 and 14a of the bridge, which substantially define its swingable span, pivot about the trunnion axis in response to delivery of power to the racks 22, 22a, in the manner to be described.

FIG. 2 shows righthand main girder 14 in full lines in bridge-closed position, and in broken lines in open position. The main girders carry a counterweight C, such as is shown in FIG. 2, although omitted from FIG. 1, in the interest of clarity of illustration.

In accordance with known practice, motor-driven gear means is provided to drive the arcuately curved racks 22 and 22a. This latter means comprises a motor 23 which may, as shown, drive a central speed reducer 24 (preferably a differential type), which is coupled to shafting 25. The shafting 25 comprises right and

lefthand shaft sections

26 and 27, respectively; and a pair of

couplings

28, 28, serve to connect these shaft sections to the central speed reducer differential-gear unit 24. The right and lefthand shaft sections, which comprise the shafting 25, extend in the direction of span width and in general parallelism with the trunnion axis In especial accordance with the present invention, a pair of

bridge'drive units

29, 29a are interposed between

shafts

26 and 27 and the respective racks 22 and 22a. These unitary devices are identical, inverted, i.e., mirror-image, counterparts, so that they have reversed left and right presentation of their input and output shafts. Therefore, only the one at the right of FIG. 1 will be described in detail. Each of these units is a housed gearing unit. They may include (though not necessarily) one or more stages of gear reduction; and in the present embodiment, each incorporates two stages of reduction, so that a relatively small input shaft may be employed. More stages of reduction may be incorporated, if needed. The respective bridge-drive units rest upon bed plates 30, 30a, which plates, in turn, are carried by pedestals 31, 31a. Substantial anchor bolts A are preferably used to secure each unit, as shown in FIG. 2. The units have input shafts 32, 32a which are coupled, each through one of a pair of coupling units 33, 33a, to the

respective shaft sections

26, 27, of drive shafting 25. For example, the input shaft 32 of the right-hand speed-reducer unit 29 is coupled, through coupling 33, to shaft 26. Each unit has an output shaft 34, or 34a, which carries a

pinion

35, or 35a, in driving engagement with an associated one of the racks 22, 22a.

Whereas, prior to this invention, the coupling of the cross-shafting to the racks was accomplished through the intermediation of a number of shafts, gears, intermediate bearings, bearing pedestals, and the like, all of which were exposed to the elements, in the present invention use is made of the versatile, housed units, 29, 29a. Each unit is especially configured and mounted to protect it from moisture, corrosion, dirt, and the like. As will become clear, as the description proceeds, these units not only may be substituted for the open gearing of existing installations, but each may be shifted vertically and/or horizontally to different locations and also may be mounted in a variety of different angular positions, about any one of the shaft axes, or about an axis parallel thereto, and can be used to drive bridge-carried racks of bridges of specifically different design, and to make adaptation for differently located central power mechanism, and also for differences in foundations or environmental arrangements. To this end the units preferably have input, intermediate, and output shafts, disposed in triangular parallelism, with differing sides in the triangle, and such shafts are mounted in special relationship to novel housing structure, which journals the units, reduces the number of parts, and seals and protects all of such parts.

The righthand, unitary speed-reducing bridge-drive mechanism (unit 29) will now be described, with particular reference to FIGS. 3 to 6, inclusive. This unitary mechanism includes three parallel shafts disposed in a particular triangular array, hereinafter more fully discussed. The first two of these shafts comprise the above-mentioned input shaft 32 carrying an input pinion 32p, and an intermediate shaft 36 carrying a gear 36g, which latter is in driven engagement with said input pinion 32p. The third shaft comprises the output shaft 34 which has a driven gear 34g in engagement with a pinion 36p carried by said intermediate shaft 36 (see particularly FIGS. 3 and 4). The output shaft 34 also carries, and thus drives, the above-mentioned output pinion 35 which is, in turn, in driving engagement with the teeth 22b of rack 22 (FIGS. I and 2).

This parallel and triangular arrangement of the input, intermediate, and output shafts lends itself particularly well to simplified mounting, and incorporation into a single separately handleable unit. As will become clear from what follows, the three shafts may be arranged in array somewhat different from the triangulation to be found in the embodiment illustrated in FIGS. 1 through 6. However, the invention contemplates such changes in array, without departing from the concept of providing bridge-drive mechanisms which comprise sealed, unitary, preferably speed-reducing gear devices, adaptable to different positions and to different environmental structures.

As will now be understood, various of the advantages of this invention are achieved by disposing the triangulated input, intermediate, and output shafts in a rigid housing structure including two very substantial parallel spaced walls, each having three bearing-carrying openings disposed in triangular array corresponding to the shaft array. A set of three openings in one of these two walls is aligned with and confronts a corresponding set in the opposite wall. These openings, and the bearings carried thereby, serve to journal the shafts with their gears sealed within the housing structure. For example, bearing means provided in one of the spaced walls serves to journal a portion 34d of the output shaft 34, which, at its outboard end 340, carries the rackdriving pinion 35.

Now making still more detailed reference to the construction of the unit 29, and to the manner in which the shaftsand gears are housed and protected, inspection of FIGS. 4 and 6 shows that the housing structure comprises a pair of spaced

side walls

37 and 38, of heavy construction, each of which carries bearings. To that end, each wall is provided with three primary bearingcarrying apertures which receive the input, intermediate and

output shafts

32, 36 and 34, respectively. The housing also has heavy wall structure 39, perpendicular to

walls

37 and 38, which may serve as a mounting base, either with the unit 29 in the position shown in FIGS. 1 to 6, or in various other positions, such, for example, as the positions shown in FIG. 7 when mounted against a vertical supporting structure 3l-V, or the oblique position shown in FIG. 8. The housing of unit 29 also has a pair of walls 40 and 4!, and a welded cover 42, with a removable access panel P for ready inspection and lubrication regardless of the mounted position of the unit.

Thus, with one triangular arrangement of the axes of the three

shafts

32, 36 and 34, a considerable variety of locations of the

central power structure

23, 24, and the drive shaft 26, and also of the rack 22, may be accommodated by a single from of drive-unit 29. In addition, it should be noted that two of the shafts in the unit, preferably the two shafts carrying the heaviest loads, i.e.,

shafts

34 and 36, may be located with their axes on the common plane of separation S of the housing; while the shaft 32 (of least load), which carries the smallest pinion (32p) is the only shaft located in what is here termed the lower box of the housing and this shaft, with its pinion 32p may be readily slipped in and out of the housing, through the aperture 43 hereinafter referred to, without the necessity of opening up the whole housing. If either of the

shafts

34 and 36, and/or their gearing and/or bearings, require inspection, repair, or replacement (beyond what may be accomplished by opening of the cover plate P), it is a rela tively simple matter to do so by separating the upper and lower box-like structures, along the plane of separation S. Other features of advantage of this arrangement will be brought out hereinafter.

It should here be noted that the

heavy bearingsupporting walls

37 and 38, and the lighter walls (at right angles thereto) 40 and 41, have upper and lower portions (when considering the unit 29 as being mounted in the position shown in FIGS. 1 to 6). the

lower portions

37, 38, 40 and 41 with the fifth wall. 39, which joins all of them, constituting a box-like structure; and the upper portions 37". 38". 40", 41", with the welded cover assembly 42 (having removable access plate P) united thereto, constituting another box structure, inverted with relation to the one first mentioned, and these box structures have mating surfaces along a common plane of separation S. Securing flanges F and F" are provided at the ends shown in FIGS. 3 and 4; and a thick stiffening structure may be provided at 37T' and 37T", adjacent to the rackdriving pinion 35, as shown in FIGS. 3 and 4. The housing formed by all of the above elements may be secured together by various screws, bolts, or other suitable fasteners B1, B2 and B3, as seen in FIGS. 3 and 4.

Considering further the specific arrangement shown in FIGS. 1 to 6, the parallel triangulation of the three shafts clearly appears in FIG. 3, and the apertures in confronting

walls

37 and 38 are disposed in corresponding array. Referring to the input shaft 32, for example, it will be seen that the wall member 38' is apertured at 43 (FIG. 6), and that the wall member 37' is apertured at 44, to receive and journal the shaft 32.

Conical roller bearings

43a and 43b, which combine radial bearing and thrust functions, are seated within the recessed

openings

43 and 44, respectively. A packing gland, designated generally at 45, seals the input end of the shaft, whereas a gasketed cover 46 shields the opposite end of the shaft.

Directly above the input shaft 32 lies the intermediate shaft 36 (FIGS. 3 and 6), which carries the intermediate'gear 36g disposed in driven engagement with the input pinion 32p. As described above, shaft 36 also carries the intermediate pinion 36p disposed in driving engagement with the output gear 34g. The intermediate shaft 36 terminates in an end portion 360 which is mounted within an aperture 47 provided in wall 37 (FIG. 6).

Bearing B may be positioned and adjusted by the cap structure 36d which also seals the aperture 47. The bearing B and cap 36d support the end 360 of the intermediate shaft 36, in manner similar to the described support and sealing of a similar portion of input shaft 32. Wall 38 is apertured at 47a in alignment with the aperture 47 provided in wall 37, and this aperture 470 receives the bearing 48 and the cap 49 which respectively journal and enclose that end of the intermediate shaft which terminates at the said housing wall 38.

Referring particularly to FIGS. 4 and 5, it will be seen that the output shaft 34 has one of its ends 340 mounted by bearings in an aperture 34 in wall 38; that end being carried by double, conical roller bearings 50, mounted in a bearing cartridge 50a. Also, that end of the shaft assembly is sealed by the gasketed member 51. The output shaft gear 343 is carried by an intermediate portion of the shaft 34, between the

apertured walls

37 and 38, and said output shaft gear is, as mentioned above, driven by the intermediate pinion 36p. Portion 34d of output shaft 34 extends through aperture 34" of the wall 37 of the housing, (which latter aperture confronts the aperture 34') and is supported in said wall by double-conical bearings 52, which serve r 7 also to take loads imposed by the pinion 35, which drives the bridge-carried rack 22 (FIG. 2). A sealcarrying cap G provides a seal around shaft portion 34d.

The pinions and gears are either formed integrally with the shafts, or are secured to their respective shafts by the use of keys. For example, the gear 34g will be seen to be keyed, at 53, to the output shaft (FIG. 4). Such securement, or integral formation, of the individual gears will be apparent from the drawings and understood without detailed description.

To facilitate assembly of the mechanism, the rigid housing structure is split into two dished sections (upper and lower sections as seen in FIGS. 1 to 6); as heretofore described. When the mechanism is assembled, the intermediate shaft 36, with its components assembled thereon, is lowered without difficulty into the semicylindrical cavities which form the lower halves of the housing apertures 47 and 47a. Similarly, the output shaft, with its components assembled thereon, is lowered into the semicylindrical cavities which form the lower halves of the

housing apertures

34 and 34". The aperture 43 in the wall 38 of the housing is large enough to permit insertion of shaft 32 and pinion 32p through that aperture.

The housng described above is, of course, supplied with suitable lubricant, and it will be appreciated that, unlike prior art arrangements, only the final output pinion 35 is disposed exteriorly of the housing, its shaft 34 being supported inboard, by the

bearings

52 and 50. In this way the maintenance requirements of the apparatus are greatly reduced.

In the interest of simplicity of illustration, the gears have been shown as spur gears. However, it will be understood that it may be desirable to use other types of gearing. For example, herringbone, helical, orother forms of gears may be employed.

With regard to installation of the described mechanism, in position to drive the bridge-carried racks (see FIGS. 1 and 2), it will now be appreciated that all of the shafts, gears, bearings, and the like, at one side of the bridge, are carried as a single unit, and that this virtually disposes of problems of initial tolerance and alignment, and problems relating to maintenance thereof within the drive train, such as are otherwise encountered in the field.

The flexibility of bridge design which these speedreducer'units afford will be clear when it is recognized that the units may be rotated to various different positions to accommodate input and output shafts residing in vertical and horizontal planes, which differ from those planes which appear in the apparatus illustrated in FIGS. 1 to 6. For example, as shown in FIG. 7, a re ducer unit 29 having shaft triangulation exactly like that already described, can be mounted in a position which is rotated 90 with respect to the position of the unit as illustrated in FIGS. 1 to 6. When utilized in a bridge having this design requirement, the output shaft 34 is disposed vertically above the intermediate shaft 36, rather than to one side thereof, and the pinion 35 is engaged with a bridge-driving rack at a location indicated fragmentarily at 22'.

As shown in FIG. 8, an oblique mounting may readily be employed to meet still other installation requirements.

Within the purview of this invention, and in addition to the adaptability provided by freedom to variously mount the drive unit (as shown by FIGS. 2, 7 and 8), the triangulation of the shafts may also be varied, further to adapt the concepts of the invention to different bridge installations. The array shown in FIGS. 1 to 8 is on shaft centers forming an irregular right-angled triangle. An alternative triangular array is shown, somewhat diagrammatically, by the unit 29 in FIG. 9. Here. the

shafts

36 and 34 are on the separation plane S of the casing (as before) but the input shaft 32 lies somewhat closer to the output shaft 34 than in the structure of FIGS. 1 to 8, forming, in this instance, a scalene triangular arrangement.

The same shafts, pinions and gears may here be used, as in the mechanism of FIGS. 1 to 8, but the center of shaft 32 is here located higher than it is in FIG. 7 (when the unit is mounted in a vertical position). As compared with FIG. 2, if the unit of FIG. 9 were mounted horizontally, the input shaft 32 would be disposed womewhat more to the right than it appears in FIG. 2. Parallelism of the shafts is retained. Utilization of this shaft array, or of others which can be devised, in novel combination with the split housing structure 29' in accordance with FIG. 9, requires only that the housing structure be modified to provide bearing-carrying openings in correspondence with the selected shaft array. If this is done, all of the above-described benefits are achieved.

In the arrangement shown in FIG. 9 (as in the arrangement of FIG. 7) the portion of the casing disposed toward the right may be considered simply as an adapter element. A differently-located mounting for shaft 32 is all that is required, as between these two interchangeable casing elements. For convenience, such casing element in FIG. 7 is designated E1, while that in FIG. 9 is designated E2. If desired, alternative mounting of the casing in different positions, upon foundations or other structures variously located, may be facilitated by providing casing element E2 with several heavy mounting walls, such as seen at 39a, 39b and 39c. FIG. 9 also shows an alternative location of the rack, as seen at 22".

It will readily be seen that the sealed drive unit will provide and maintain adequate lubrication of all moving parts within the casing, in any of the mounting positions for which the unit is adapted, since the configuration is such that one or more of the pinions and gears will subject it to the oil bath in the casing and will act to carry or splash oil on other moving parts.

It should also be noted that in the event of failure of any part of the mechanism, or in case of wear of parts beyond a predetermined limit, the entire bridge-drive unit may be disconnected from its foundation, and the coupling of the input shaft also disconnects, and the entire unit can then be pulled or lifted out of the bridge installation, and a counterpart unit put into place and coupled up for operation, with a minimum down-time for the bridge as a whole.

In conclusion, it is intended that the entire disclosure be considered as illustrative, and as limited only by the claims, and that the latter be construed as broadly as permitted by the prior art.

We claim:

1. A bascule bridge assembly comprising a rack at each side of the bridge, counterpart inverted right and left-hand sealed gear-drive units, each having an outwardly-extending shaft carrying an external pinion engaging one of said racks, each of said units having a power-input shaft having an external connection device, and a power-actuated differential-drive mechanism disposed between said inverted units and coupled to said external connection devices.

2. ln bridge-operating machinery having power-drive shafting and a bridge-operating rack, a sealed geardrive unit operatively associated with said shafting and said rack, and comprising a plurality of geared shafts, including a powerinput shaft, a rack-driving output shaft and an intermediate shaft, and further comprising a split housing having at least two cooperating casing members configured with mating surfaces adapted to be sealed together and having, adjacent to said surfaces, mounting means for bearings of a plurality of spaced-apart geared shafts, one of which is said output shaft which extends outside of the housing and there carries a pinion positioned to actuate the rack, and another of which is the said intermediate shaft, and one of said casing members carries bearing means for the power-input shaft which has means for coupling it to said power-drive shafting, said input shaft being centered on an axis spaced from the centers of the two shafts first-mentioned, in such relation that the three mentioned shaft centers are at points forming a triangle.

3. The construction of claim 2 wherein the said coupling means and said rack-driving pinion are at opposite sides of said housing.

4. The construction of claim 2 wherein the housing has means for mounting it in any one of a plurality of positions so as to accommodate different relative locations of said shafting and said rack with respect to an environmental base.

5. The construction of claim 2 wherein said triangle is an irregular triangle.

6. The construction of claim 2 wherein said triangle is a right-angled triangle.

7. The construction of claim 2 wherein said casing member which carries bearing means for said input shaft is formed as a replaceable adapter element whereby the location of the axial cneter of the input shaft may be altered relative to the location of another shaft center.

8. The construction of claim 4 wherein the housing comprises heavy opposed walls adapted to carry the mounting means for the shaft bearings, and the means for mounting the housing includes rigid structure generally at right angles to said walls.

9. The construction of claim 8 wherein the lastnamed structure is generally parallel with the shaft axes.

10. The construction of claim 2 wherein at least two of the geared shafts comprise reduction gearing.

11. The construction of claim 2 wherein there is reduction gearing between the input shaft and said intermediate shaft and also between the latter and the said output shaft.

12. The construction of claim 4 wherein the sealed housing provides a lubricant vessel so configured as to lubricate housed gearing therein regardless of the position in which the unit is mounted.

13. The construction of claim 4 wherein a removable access cover is so positioned on the housing as to be accessible in the various positions of mounting of the unit.

14. In a bascule bridge construction, trunnion means, a bascule span pivotally supported upon said trunnion means, to accommodate swinging movements of said span, about an axis defined by said trunnion means, an arcuately curved rack secured to said bascule span with its center of curvature on said axis. and heavy-duty gear-drive means for driving said rack to swing said span and movable for opening and closing of the latter, said gear-drive means comprising: motor-driven shafting; a speed-reducer mechanism for delivering power from said shafting to said rack, said mechanism including at least three parallel shafts, disposed in triangular array and comprising a gear-carrying input shaft coupled to said shafting, a gear-carrying intermediate shaft in driven engagement gear-carrying said input shaft, and a gear-carring output shaft in driven engagement with said intermediate shaft, said output shaft carrying a pinion disposed to drive said rack; and means mounting said speed-reducer mechanism as a unitary sealed assembly, said last means comprising rigid housing structure including parallel, spaced, walls each having openings disposed in triangular array corresponding to the shaft array, and confronting similar openings in the other wall, one set of corresponding and confronting openings serving to mount said input shaft within said housing structure, another set of corresponding and confronting openings serving to mount said intermediate shaft within said housing structure, and a third set of corresponding and confronting openings serving to mount said output shaft within said housing structure, a portion of said output shaft extending through one of the confronting openings of the third set and carrying said pinion.

15. A bridge construction in accordance with claim 14 and in which said rigid housing structure includes two complementary, dished sections configured and disposed to define said parallel spaced walls and to mount and seal said speed-reducer mechanism, each section terminating in mating surfaces confronting and sealed against similar surfaces of the other section, said surfaces lying generally in a plane containing the axes of two of said three parallel shafts, and said two sections of said housing structures being separably secured at said plane.

16. A bridge construction as defined in claim 15 and further characterized in that said two shafts comprise said intermediate shaft and said output shaft.

17. A bridge construction as defined in claim 16 and further characterized in that: the portion of said input shaft which is coupled to said shafting extends through a wall region of one only of said sections.

18. In a bascule bridge construction, a pair of trunnions, a bascule span including spaced main girder means each pivotally supported upon a corresponding one of said pair of trunnions, to accommodate swinging movements of said span about an axis defined by said trunnions, a pair of arcuately curved racks, each secured to a corresponding one of said main girder means with its center of curvature on said axis, and heavy-duty gear-drive means for driving said racks to swing said span and provide for opening and closing of the latter, said gear-drive means comprising: motor means; shafting coupled to said motor means, extending in general parallelism with said axis, and substantially spanning the distance between the girder-supported racks; a pair of speed-reducer mechanisms for delivering power from portions of said shafting to a corresponding one of said racks, each speed-reducer mechanism including three parallel shafts, disposed in triangular array, and comprising an input shaft coupled to said shafting and carrying an input pinion, an intermediate shaft carrying an intermediate gear in driven engagement with said input pinion and carrying a second pinion, and an output shaft carrying an output pinion and having a gear in driven engagement with said intermediate pinion, the output pinion of each speed-reducer mechanism being in driving engagement with one of said racks; and means mounting each such speed-reducer mechanism as a single unitary assembly and protecting the same from corrosion, dirt and the like, said last means comprising rigid housing structure including parallel, spaced, walls each having three bearing-carrying openings disposed in triangular array corresponding to the shaft array, and confronting similar openings in the other wall, one set of corresponding and confronting openings, and the bearings thereof, serving to journal said input shaft with its pinion enclosed within said housing structure, another set of corresponding and confronting openings, and the bearings thereof, serving to journal said intermediate shaft with its gear and its pinion enclosed within said housing structure. and a third set of corresponding and confronting openings, and the bearings thereof, serving to journal said output shaft with its driven gear enclosed within said housing structure and its rack-driving pinion mounted exteriorly of said housing structure upon a free end portion of said output shaft which extends through one of the confronting openings of said third set.

19. A bridge construction in accordance with claim 18 and further including means sealing said shafts in the bearing-carrying openings in said spaced walls.

Claims

2. In bridge-operating machinery having power-drive shafting and a bridge-operating rack, a sealed gear-drive unit operatively associated with said shafting and said rack, and comprising a plurality of geared shafts, including a powerinput shaft, a rack-driving output shaft and an intermediate shaft, and further comprising a split housing having at least two cooperating casing members configured with mating surfaces adapted to be sealed together and having, adjacent to said surfaces, mounting means for bearings of a plurality of spaced-apart geared shafts, one of which is said output shaft which extends outside of the housing and there carries a pinion positioned to actuate the rack, and another of which is the said intermediate shaft, and one of said casing members carries bearing means for the power-input shaft which has means for coupling it to said power-drive shafting, said input shaft being centered on an axis spaced from the centers of the two shafts first-mentioned, in such relation that the three mentioned shaft centers are at points forming a triangle.

5. The construction of claim 2 wherein said triangle is an irregular triangle.

9. The construction of claim 8 wherein the last-named structure is generally parallel with the shaft axes.

14. In a bascule bridge construction, trunnion means, a bascule span pivotally supported upon said trunnion means, to accommodate swinging movements of said span, about an axis defined by said trunnion means, an arcuately curved rack secured to said bascule span with its center of curvature on said axis, and heavy-duty gear-drive means for driving said rack to swing said span and movable for opening and closing of the latter, said gear-drive means comprising: motor-driven shafting; a speed-reducer mechanism for delivering power from said shafting to said rack, said mechanism including at least three parallel shafts, disposed in triangular array and comprising a gear-carrying input shaft coupled to said shafting, a gear-carrying intermediate shaft in driven engagement gear-carrying said input shaft, and a gear-carring output shaft in driven engagement with said intermediate shaft, said output shaft carrying a pinion disposed to drive said rack; and means mounting said speed-reducer mechanism as a unitary sealed assembly, said last means comprising rigid housing structure including parallel, spaced, walls each having openings disposed in triangular array corresponding to the shaft array, and confronting similar openings in the other wall, one set of corresponding and confronting openings serving to mount said input shaft within said housing structure, another set of corresponding and confronting openings serving to mount said intermediate shaft within said housing structure, and a third set of corresponding and confronting openings serving to mount said output shaft within said housing structure, a portion of said output shaft extending through one of the confronting openings of the third set and carrying said pinion.

18. In a bascule bridge construction, a pair of trunnions, a bascule span including spaced main girder means each pivotally suppOrted upon a corresponding one of said pair of trunnions, to accommodate swinging movements of said span about an axis defined by said trunnions, a pair of arcuately curved racks, each secured to a corresponding one of said main girder means with its center of curvature on said axis, and heavy-duty gear-drive means for driving said racks to swing said span and provide for opening and closing of the latter, said gear-drive means comprising: motor means; shafting coupled to said motor means, extending in general parallelism with said axis, and substantially spanning the distance between the girder-supported racks; a pair of speedreducer mechanisms for delivering power from portions of said shafting to a corresponding one of said racks, each speed-reducer mechanism including three parallel shafts, disposed in triangular array, and comprising an input shaft coupled to said shafting and carrying an input pinion, an intermediate shaft carrying an intermediate gear in driven engagement with said input pinion and carrying a second pinion, and an output shaft carrying an output pinion and having a gear in driven engagement with said intermediate pinion, the output pinion of each speed-reducer mechanism being in driving engagement with one of said racks; and means mounting each such speed-reducer mechanism as a single unitary assembly and protecting the same from corrosion, dirt and the like, said last means comprising rigid housing structure including parallel, spaced, walls each having three bearingcarrying openings disposed in triangular array corresponding to the shaft array, and confronting similar openings in the other wall, one set of corresponding and confronting openings, and the bearings thereof, serving to journal said input shaft with its pinion enclosed within said housing structure, another set of corresponding and confronting openings, and the bearings thereof, serving to journal said intermediate shaft with its gear and its pinion enclosed within said housing structure, and a third set of corresponding and confronting openings, and the bearings thereof, serving to journal said output shaft with its driven gear enclosed within said housing structure and its rack-driving pinion mounted exteriorly of said housing structure upon a free end portion of said output shaft which extends through one of the confronting openings of said third set.