US1246478A

US1246478A - Turn-table end truck and tractor.

Info

Publication number: US1246478A
Application number: US15549217A
Authority: US
Inventors: Louis H Shoemaker
Original assignee: Individual
Current assignee: Individual
Priority date: 1917-03-17
Filing date: 1917-03-17
Publication date: 1917-11-13
Anticipated expiration: 1934-11-13

Description

L.-H. SHOEMAKER.

TURN TABLE END TRUCK AND TRACTOR;

APPLICATTQN FILED MAR. 17, I917.

' 1,246,478. Patented Nov. 13, 1917.

8 SHEETS-SHEET I. v

WITNESSES INVENTOR ms NORRIS PETERS co, PnorauTun..WAslmcn1-. u. c.

8 SHEETSSHEE,T 2.

PittBIltBd NOV. 13, 1917.

fix

L.- H. SHOEMAKER.

TURN TABLE END TRUCK AND TRACTOR.

APPUCATION map MAR. 17. 1911.

L.H. SHOEMAKER.

TURN TABLE END TRUCK AND TRACTOR.

APPLlCATlOfl FILED MAR-12.1917- 1,246,478.

Patented-Nov. 13, 1917.

8SHEETS-SHEET a.

FIG. 5

FIG. 6

FIG. 7

if 47 FIGG INVENTOR WITNESSES fl/M L. H. SHOEMAKER.

TURNTABLE END TRUCK AND TRACTOR! APPLICATION FILED MAR. 17. I917.

1 46,478. Patnted Nov. 13, 191%.

8 SHEETS-SHEET 4.

FIG. 1 2 /03 WITNESSES INVENTOR WWM m: Nui'ms PETERS co.. Pnomn-mo WASHINGIOH, u c.

L. H.'SHOEMAKEB.

TURN TABLE END TRUCK AND TRACTOR. 7

APPLICATION man 111111.11. 1911.

8 SHEETS- 8H! 5.

78 FIGJOA 75 70 FIG-.11 9/ I 0 o 0 0 o o o o o. o 01 g o o o o o o o o & a 0 o o o 0 6a 0 o 67 o 0 o 88 o 0 o 86 0 0 o 9 4/ A4 a 0 Wji 0 Q o 00 0 0 WITNESSES INVENTOR m: NORRIS runs ca, Puomuma. vusnnvcmu. A c.

' L. H. SHOEMAKER TURN TABLE END TRUCK AND TRACTOR. APPLlCKT/ION men MAR-.11 1911.

Patented Nov. 13,. 1917.

a SHEETS-SHEET6.

WITNESSES Q m: Noiuls puns cm. Puum-umuu wAsmncron. u. c.

Patented Nov. 13, 1917.

3SHEETS-SHEET 7- l N V ENTO R M W. W

L. H. SHOEMAKER.

TURN TABLE END TRUCK AND TRACTOR.

' APPLICATION FILED MAR. 17, I917- ms Nam-us Psvsns ca, PHOTD-LIYHQ. wAsnmcw-ulv. o. c.

L. H. SHOEMAKER;

wan TABLE END TRUCK AND TRACTOR.

APPLICATION FILED MAR. 17, I911.

1 246,478. 7 Patented Nov. 13, 191 7.

8 SHEETS-SHEET B.

' Q Q v WITNESSES INVENTOR m y iQMK/M WWM i n4: Nmwms perms ca. Pnomumo WASNINU mu. n c

unirnn sra'rns LOUIS H. HOEMAKERi or PITTSBURGH, PENNSYLVANIA.

TURN-TABLE END TRUCK AND TRACTOR.

Specification of Letters Patent.

Patented Nov. 13. 191?.

Application filed March 17, 1917. Serial No. 155,492.

and State of Pennsylvania, have invented.

certain new and useful Improvements in Turn-Table End Trucks and Tractors, of which the following is a specification.

My invention relates to apparatus known" as turntables and used in turning end for end the locomotives or other rolling stock of railroads, and more particularly relates to the construction of the turntable end trucks and to the driving mechanism for actuating the traction wheels on the end trucks.

One object of the invention is to'provide a turntable of improved construction wherein the end trucks, in a vertical plane, are flexibly connected, and in a horizontal plane, are rigidly connected to the main girders of the turntable to thereby permit of limited vertical movement and prevent any substantial relative horizontal movement between the trucks and girders.

Another object of the invention is to provide a turntable of novel construction hav ing a combined end truck and tractor for supporting the ends of the turntable girders, and for supplying the tractive force necessary in turning or rotating the turn table.

A further object of my invention is to provide a turntable having sectional end trucks and having the truck sections rigidly connected horizontally and flexibly connected vertically to prevent relative horizontal movement and to permit of limited vertical movement of the end sections of the truck relative to each other.

A. still further object of the invention is to provide a turntable having improved driving means whereby the traction Wheels on the flexibly connected end sections of the trucks are driven by a motor positioned on the turntable girders.

Still further objects of my invention con-- sist 1n the provision of a power actuated turntable having the parts and novel arrangements. constructions, and combinations of parts shown in the drawings, more fully described hereinafter, and specifically covered by the appended claims Referring now to the drawings, forming part of this'specification, Figure 1 is a plan,

partly in section, showing one end ofa "through turntable having a comblned end truck and tractor constructed and arranged and connected to the turntable girders in accordance with my invention.

Fig. 2 is a transverse sectional elevation of the end truck shown in Fig. 1, the section being taken on the line I'll-11 of Fig. 1.

Fig. 2 is a side elevation showing details in the construction of the vertically flexible and horizontal rigid connection between the intermediate section and end sections of the truck frames of Figs. 1 and 2.

Fig. 3. is a sectional elevation on a larger scale, taken on the line liHHI of Fig. 1, showing details in the construction and arrangement of the driving gears employed in operatively connecting the traction wheels with the turntable driving motor of Figs. 1 and 2. Fig. 4 is a sectional elevation showing de tails in the construction and arrangement of the transverse bevel-gear shafts and shaft bearings used with the turntable of Figs. 1 and 2. the section being taken on the line lVIV of Fig. 1.

Fig. 5 is a. sectional elevation, on the irregular line V-V of Fig. 1, showing one construction and arrangement of means for connecting the end trucks to the turntable girders in accordance with my invention.

Fig. (.3 is a detail sectional levation, taken on the line VI-VI of Fig. 1, showing the turntable track wheels as mounted on the end trucks of the turntable of Figs. 1 to 5.

Fig. '7 is a sectional elevation on the line VlI-Vll of Fig. 1, showing the turntable driving motor and support therefor, as mounted on the longitudinal girders of the turntable.

Fig. 8 is a diagrammatic one arrangement of shafting for driving turntables constructed in accordance with this invention.

Fig. 9 is a plan, partly in section, showing one end of a deck turntable having an end truck and turntable driving mecha-- nism constructed and arranged in accordance with my inyention.

Fig. 10 is a sectional end elevation of the same. the section being taken on the line X-X of Fig. 9.

Fig. 10 is a side elevation showing details in the construction of the vertically flexible, horizontallv rigid connections beplan showing.

tween the contiguous ends of the sections of the sectional truck frame used with the "'deck turntable of Figs. 9 to 12-.

I Fig. 11 is a sectional elevation on the line XI-XI of Fig. 9 showing the sectional end truck of Figs. 9 and 10 connected to the turntable girders in accordance with my invention so as to be horizontally rigid and vertically movable relative thereto.

Fig. 12 is a sectional elevation, taken on the line XII-XII of Fig. 9, showing details in the arrangement of driving gears connecting the driving shaft and traction wheels of the turntable end trucks of Figs. 9, 10, and 11.

Fig. 13 is a plan partly in section showing details in the construction and arrangement of a modified form of turntable made in accordance with my invention.

Fig. 14 is a sectional end elevation of the same, the section being taken on the irregular line XIV-XIV of Fig. 13.

Fig. 15 is a sectional end elevation, on the line XVXV of Fig. 13, showing the driving gears by which the driven wheels of the turntable end trucks are actuated, as constructed and arranged in accordance with this invention.

Fig. 16 is a longitudinal side elevation, part1 broken away and partly in section, showing details in the construction of the turntable of Figs. 13, 14, and 15.

In the construction illustrated by Figs. 1 to 8 of the accompanying drawings, which show a through turntable, the two parallel mainor longitudinal girders 22 are obnnected at their ends by transverse girders 3, and, at suitable intervals in the length thereof, by similar transverse girders 4. EX- tending between the transverse girders are longitudinal beams or girders 5 and girders 6 having their ends connected to thetransverse girders 3, 4, the girders 5 and 6 supporting the ties 7 for the locomotive track rails 8, S of the turntable. The upper surfaces of the top cover plates of the main girders 2 are in a plane considerably above that of the upper surfaces of the girders-3 and 4 and the upper surfaces of the girders 3 and 4 are in a plane above that of the uppermost surfaces of the top flanges of the beams 5 and girders 6, this arrangement effecting a material reduction in the necessary over-all height of the through turntable. (See Fig. 2).

A rectangular opening 9 is formed in the web 10 of the main girders 2, adjacent to each end of these girders, thev web being reinforced by vertical stiffening members 1.1, 12, and horizontal members 13 to compensate for the material removed in making the openings 9. (See Figs. 1, 2, and 5).

The ends of the main girders 2 of the turntable are supported by sectional, wheeled trucks, the trucks being formed of two short ing the

short end sections

14, 14, which are connected .to the ends of a longer intermediate sectlonlo (see Figs. 1, 2, and 2 and an end section 14 of the'trucks projects through each of the openings 9 in the main girders 2.

The contiguous ends of the beams formend

sections

14, 14, and long intermediate section 15 of the trucks are fastened together by angle connections 16 which are riveted thereto so as to make the trucks horizontally rigid and vertically flexible, the

filler plates

17, 17, providing a small amount of clearance 18 between the connected ends of the beams forming the truck sections. (See Fig. 2

The pairs of short beams forming each end section 14 of the trucks .are connected at their ends by plates 19, and, at an intermediate point, by a centrally locatedspring support 20. (Bee Figs. 2 and 2 The ends of eachend section 14 of the trucks also are connected to the longitudinal girders 2 by diagonal braces or struts 14 which hold the trucks rigidly against horizontal movement relative to the girders. The connection plates on the ends of the struts 14 are flexible enough to permit of the desired slight vertical movement of the end sections 14 of each truck relative to the turntable girders 2 and to one another.

The spring support 20 which=-is located within an opening 9 in the web of the girders 2 has an integral upwardly projecting cylindrical member 21, the upper end of which is rounded to be hemispherical, this rounded end of the projection 21 engaging with the hemispherical depression .in the lower surface of the saddle 22 which is positioned in the openings 9in the web of the turntable girders 2 to limit the vertical rocking moveinent of the main girders relative to the sectional trucks, which occurs during the transfer of locomotives or other rolling stock to and from the turntable.

The spring support 20 also has cylindrical projections 23 on its opposite sides (see Fig. 5), these projections extending through openings in the web of the beams forming the end sections 14 of the trucks. and bolts 24, which preferably are body-bound, are employed to fasten the support 20 in place between the pairs of beams 14, and also to hold these beams in spaced relation.

The outer ends of the projections 23 are rounded and extend into vertical grooves 25 formed in the

vertical guides

26, 26, the guides being fastened to the vertical sides of the openings 9 in the ends of the main girders 2, and the projections 23 by engageunent of the side walls of the grooves 25 in the girders 26 preventing horizontal movement of the trucks relative to the main girders, while permitting limited vertical movement therebetween. (See Fig. 5i.

A helical spring 27 is positioned between vided with a the end sections t eatre the supports 20 and saddles 22 to connect the supports and saddles, the springs 27 being put into position under considerable -compression, so that the longitudinal girders 2 will be yieldingly supported at their ends when the turntable is empt and the weight of the. ends of the turntab e will be equally distributedon the four end trucks.

The end action it of each truck projects through one of the openings 9 in each end of the girders 2, and each end section 14 is propair of

wheels

28, 29, which are keyed on the

axles

30, 31 for the wheels. The axles are rotatably mounted in

bearings

32, 32, and 33, 33, which are secured in pairs to the bottom flanges of the 14; and the

wheels

28, 29 engage with and are supported upon the circular track formed by the rail 3a in the pit in which the turntable is rotatably mounted.

It will, of course, be understood that in each construction shown, the turntable is supported at the middle of its length upon a pivot or center bearing, in the usual known manner, so that the turntable is balanced thereon when empty, any center bearing of approved form being used, as fol-example, the bearing 108 shown in Fig. 16.

On account of the connections between the outer or short end sections 14 and longer intermediate section 15 of the trucks being flexible in a vertical direction, each end section 1 to a small extent is movable vertically relative to the middle section 15 and opposite end section 1%, and being rigidly connected together horizontally, any relative horizontal movement of the truck sections is prevented. In this way the load on the turntable is caused to be uniformly distributed upon each wheel of the trucks, even when irregularities are present in the tread surface of the circular track rail 34:.

Secured on one end of the axles 31 (or axles for the inner wheels 29) are bevel gears 36' which mesh with bevel pinions 37 on the ends of horizontal shafts 33- The shafts 38 are mounted at their ends in bearings 39 which are secured by brackets 40 to the beams'forming the intermediate sections 15 of the trucks.

Although the shafts 38 and bevel pinions 37 are mounted on the intermediate sections 15 and the track wheels 29 and bevel gears 36 on the end sections 14 of the trucks, the relative vertical movement of the sections is so slight and the locating of the bevel gears relative to the position of the flexible connections between the truck sections is so nearly central, as to maintain the

gears

36, 37, in mesh at all times.

The adjoinin ends of the two

shafts

38, 38, have bevel pinions d1 thereon which mesh with a bevel gear 42 on the lowermost horizontal cross or countershaft 4-3 which is sections of the beams forming mounted in bearings 44, 4A, suspended from the beams forming the intermediate section 15 of each truck. A spur gear 45 on the shaft 43 meshes with a similar spur gear 46 on the idler shaft 47 which is mounted in bearings 48, d8, on the top flanges of the beams forming the intermediate section 15 of the trucks. (See Figs. 1, 2, and 3). The spur gear 49 on one end of the countershaft 47 meshes with the spur pinion 50 on one end of the long horizontal shaft 51 which extends lengthwise parallel with the main. girders 2 of the turntable. The shaft 51 is mounted in the

bearings

52, 52 and, when its length requires, the shaft 51 also is provided with intermediate bearings. While the shaft 51 for each truck carrying the spur -pin1ons 50 are mounted on the turntable girders and the shafts 43 and 47 having the spur gears 45, 46 and 48 thereon areon the truck frames, the gear 49 and pinion 50 will remain in. mesh during the slight relative vertical movement of the truck frames and girders of the turntable.

The

shafts

51, 51, which extend lengthwise from each end toward the transverse center of the turntable are provided on their adjacent ends with

bevel gears

53, 53, meshing with the bevel gear 54 on one end of the horizontal cross-shaft 55 which is conveniently located adjacent to the middle of the length of the turntable. The shaft 55 is mounted in

bearings

56, 57, and has a spur gear 58 on. oneend which is in mesh with the spur pinion 59 on one end of the armature shaft '60 of the electric driving motor 61. The motor 61 is secured on a suitable bracket 62 fastened to one of the main girders 2 of the turntable, beneath the operators platform 63 which is located on one side of the turntable. (See Figs. 7 and 8).

In the deck type of turntable shown by Figs. 9 to 12 the parallel

longitudinal girders

64, 64, are not widely spaced as inthe through type of turntable, and the ties 65 for the locomotive track rails 66 rest on the I cover plates 67 of the longitudinal girders, (SeeFig. 10). a

Each end of the two longitudinal girders 64 has a rectangular opening 68 in its web 69, through which the sectional truck frames project, the web of the girders being strengthened adjacent to the rectangular openings by angles 70 and '71. The girders 64 are fastened together in spaced relation by diagonal bracing 72 and at their ends and suitable points in the length thereof, by cross girders or bracing 73, in the usual known manner.

Each truck frame has end sections 74;, 74 formed of pairs of parallel beams which are connected at one end thereof by tie plates 75 to the ends of the pairs of beams 7 6 forming the intermediate section of each truck frame. The connecting plates 75 rigidly fasten the truck frame sections together against relative horizontal movement, while flexibly connecting the sections so as to permit of a limited vertical movement of each end section relative to the other and also relative to the girders 64:. (See Figs. 10 and 10 The pair of beams forming the end sections 74 of the truck frames are fastened together by means of end plates 7 7 7 8 and, on the top flanges thereof by

plates

79, 80. The end sections of the flexible truck frames also are connected to the ends of the main or longitudinal girders by struts or diagonal bracing 81 and 82 so as to prevent relative horizontal movement of the truck frame and girders while permitting a limited amount of relative vertical movement between the main girders and end sections of the truck frames and between the truck sections. (See Fig. 9). i

Each opening 68 in the endsiof the main ders 64 is provided with a spring follower or saddle 83 and each end sectidn of the truck frames'is provided with a spring support 84 which is fastened by bolts. 85 between the pair of beams forming each end section 74. The sides of the castings forming the spring supports 84: have integral projecting stubs or pins 86 which extend through holes in the webs of the beams 7 these pins forming uides which extend into the vertical slots ormed by the parallel ribs 87 on the guide plates 88 of which one is secured on each end of the rectangular openings 68 in the main or longitudinal girders. (See Fig. 11).

The horizontally projecting pins .86, by engagement with the vertical ribs 87 act to prevent any horizontal movement of the truck frame sections with respect to each other and to the main girders 64, while permitting the desired slight relative vertical movement between the sections of each truck frameand between the sectional truck frames and main girders of the turntable.

Positioned between each saddle 83 and support 84 is a helical spring 89, thesesprings being placed in position under an initial compression, inthe particular springs shown the initial compression being about one inch, so that when the turntable is empty the ends of the longitudinal girders 64 will be held in respect to the truck frames, in the lifted position shown in Fig. 11, by the springs 89. r

The upwardly extending projection 90 on the supports 84 and downwardly extending progection 91 on the saddles 83 by engagement of their rounded or concavo-convex abutting ends, coact to limit the downward or tilting movement of the ends of the longitudinal girders 6 1 when the maximum .load is applied to the end of the turntable, as when a locomotive is passing on or off the turntable.

frame end sections 74. Secured on one end of the axles 96 for the inner wheel 93 on each end section 7 4 of the trucks is a gear 98 having slightly beveled teeth, Qsee Fig. 12) and meshing with the gear 98 is a similar gear 99 which is secured on one end vof a countershaft 100. This countershaft is mounted in bearings 101-101 which are suspended from the lower flange of the beams forming the intermediate section 76 of the truck frames, and has a spur gear 102 on one end which meshes with a spur pinion 103 on one end of the idler shaft 104. The shaft 104 is rotatably mounted in

bearings

105, 105 which are fastened on the upper flanges ofthe beams formin the intermediate section of each truck rame and the idler pinion 103 on the shaft also meshes with the spur driving pinion 106 on the horizontal driving shaft 107. (See Figs. 9, 10, and 12). Theushaft 107 is mounted in suitable bearings-108, which are supported from the. cross girders of the turntable and at suitable intervals in the length thereof by" transverse girdersllO.

The main girders 108 are supported at the middle of their length upon a pivot or center bearing 108*, this bearing, which may be any of the various known constructions adapted for such use, being connected to twotransverse girders 110, and restingupon a foundation in the center of the pit in which the turntable is mounted.

, The wheeled trucks on each end of the main girders 108 are formed of end sections 111, 111. and a short middle section 112, to which the end sections are fixedly connected, so as to permit of a slight vertical movement of one end section relative to the other and rigidly connected to prevent any relative horizontal movement between the truck sections.

Diagonal brac'es

113, 114 are employed to rigidly connect the ends of the outer truck sections 111 to theilongitudinal girders 108 in a horizontal plane and prevent horizontal movement of the trucks relative to the main girders, while the connections for the bracing are ,made

rea ers flexible enough to permit of the desired limited amount of vertical movement between the trucks and main girders. (See Fig. 13).

The end sections 111 of the trucks are formed of beams arranged in pairs with the ends of the beams in each pair connected by end plates 115 and angles 116, and between the beams of each pair forming each end section of the trucks are the two

track wheels

117, 118, these wheels being keyed or otherwise fastened to shafts or axles 119 and 120, and the axles being mounted in airs of bearings 121121and 122-122 W ich are fastened on the lower flanges of the beams forming the end sections of the trucks. Positioned between the webs of the beams at about the middle of the length of each end Section of the trucks and placed back to back are short channel beams 123, these channel beams forming supports for the

helical springs

124, 125, by which the ends of the main girders 108 are yieldingly held in place on the turntable end trucks. Positioned within the rectangular opening 126 in each end of the two main girders 108 (see Figs. 14, 15 and 16) are top and

bottom follower plates

127, 128, these plates having projections 129 on one face thereof which engage with sides of the adjacent flanges of the beams formin each end section or the truck. the flanges of the beams bein notched and the projections engaging t erewith and forming guides for the follower plates. Positioned between the short channel beams 123 on the end sections of the trucks and the top and

bottom follower plates

127, 128, are the

helical springs

124 and 125, one on each side of the channel beams. The uppermost spring 124 is heavier or of larger size than the lower one 125 and both springs are put into place under considerable compression. The upper s ring 124 being the stronger will tend to and hold the ends of the girders 108 in raised position when the turntable is empty, and when a load such as a locomotive is balanced on the turntable, while the lower ring 125 will form a cushion which absor s the shock transmitted when a locomotive is passing upon'or being removed from the turntable.

Keyed or otherwise secured on the overhanging end of the-axles 120 for the track wheels 118 is a bevel gear 130. The gear wheels 130 mesh with a bevel pinion 131 which is keyed on the horizontal shaft 132 extending from the end of the main girders toward the middle of the length of the turntable. One end of the horizontal shafts 132 is mounted in a bearing 133 which is secured on the intermediate section 112 of the end trucks, and the shafts 132 are also supported at suitable intervals in their length, 111 bearings 13% mounted on the transverse girders 110 which connect the two main gi! ders 108. The adjacent ends of the two horir-aaital shafts 132 are provided with bevel gears 135 which mesh with a bevel pinion 136 on the horizontal cross shaft 137 located adjacent to the center of the length of the main girders. The cross shaft 137 is connected by a coupling 138 to a motor -countershaft 139 and the countershaft 139 is connected by suitable reducing gears 110, 111 to the armature shaft 142 of the driving motor 143.

The motor is supported on a bracket fastened on the side of one of 108.

The turntables shown in Figs. 13 to 16 being of the deck type, the ties 146 are supported on the topcover plates of the'mam girders 108 and the rails 147 forming the track on the turntable are directly supported upon the ties.

I do not claim to be the first to construct a. turntable having a wheeled truckprovided with a rocking non-pivotal bearing upon the turntable.

The advantages obtained with turntables made in accordance with my invention will be appreciated by those skilled in the art. The sectional end trucks, when connected to the main girders in the manner shown and described, enable a load on the turntable to be uniformly distributed upon'the wheels of the trucks. The wheels on the sectional and vertically movable trucks are positively the main girders driven by a motor positioned on the turntable girders. The springs used in connecting the girders to the tracks act as absorbers which cushion, the shocks caused by the transfer of locomotives, or other rolling stock to or from the turntable.

Modifications in the construction and arrangement of the parts forming my improved turntable constructions may be made without departing from my invention as defined in the appended claims.

I claim:

1. A turntable comprising main girders, a center bearing therefor, wheeled trucks at the ends of said girders, said trucks being made in sections, means connecting the trucks to the main girders arranged to permit of limited relative vertical movement and prevent relative horizontal movement therebetween, means connecting the truck sections arranged to permit of limited ver-. tical movement while preventing relative horizontal movement of one end section relative to the opposite end section of the trucks and means for rotating the turntable.

2. A turntable comprising main girders, a center bearing therefor, wheeled trucks at the ends of said girders, said trucks being made in sections, means connecting the trucks to the main girders arranged to permit of limited. relative vertical movement an" prevent relative horizontal movement tl erebetween, means connecting the truck sections arranged to permit of limited verfl i therebetween, means connecting the truck tical movement while preventing relative horizontal movement of one end section relative to the opposite end section of the trucks and a motor on the turntable girders arranged to rotate the turntable.

3. A turntable comprising main girders, a center bearing therefor, wheeled trucks at the ends of said girders, said trucks being made in sections, means connecting the trucks to the main girders arranged to permit of limited relative vertical movement prevent relative horizontal movement sections arranged to permit of limited vertical movement while preventing relative horizontal movement ofone end section relative to the opposite end section of the trucks, a motor on said main girders and reducing gearing operatively connecting the motor and the traction wheels on said trucks.

' a center bearing therefor, w eeled trucks at the ends ofsaid girders, said trucks being made in sections, means connecting the trucks to the main girders arranged to permit of limited relative vertical movement and prevent relative horizontal movement therebetween, means connecting the truck sections arranged to permit of limited vertical movement while preventing relative horizontal movement of one end section relative to the opposite end section of the trucks, a motor on said main girders and reducing gearing operatively connecting the motor and the traction wheels on said trucks, said reducing gearing being positioned and arranged to permit of limited vertical movement of the trucks relative to the main girders without disengagement of the gears.

5. A turntable comprising parallel main girders, a center bearing therefor, a sectional truck on at least one end of the girders, a driven traction wheel on said truck, and means connecting the truck sections to permit of limited vertical movement and prevent horizontal movement of one truck section relative to another section thereof.

6. A turntable comprising parallel main girders, a sectional truck on at least one end of said girders having a driven traction wheel, means connecting the truck sections to permit of limited vertical movement and prevent horizontal movement of one truck section relative to another section thereof, a motor on said turntable and means operativelv connecting the motor and said driven traction wheel.

7. A turntable comprising main girders, sectional trucks to support the ends of said girders, means connecting said trucks to the ends of the girders to prevent horizontal movement of the trucks relative to the girders, said means yieidingly connecting the ends of said girders tot-he trucks to permit of limited vertical movement of the girders relative tothe trucks, traction wheels on said trucks, and means for positively rotating said traction wheels.

8. A turntable comprising main girders,

sectional trucks to support the ends of said.

girders, means connecting said trucks to the ends of the girders to: prevent horizontal movement of the trucks relative to the girders, said means yieldingly connecting the ends of said girders to the trucks to permit ers, said means yieldingly connecting the ends of said girders to the trucks to permit of limited vertical movement of the girders relative to the trucks, traction wheels on said trucks, and means for positively rotating the traction wheels on, at least one of said trucks.

10. A turntable comprising main girders, sectional trucksto support the ends of said girders, means connecting said trucks to the ends of said girders to prevent horizontal movement of the trucks relative to the girders, said means having springs yieldingly connecting the girders and trucks to permit of limited vertical movement of the girders relative to the trucks, means. for limiting said vertical movement, traction wheels on the trucks, and means for positively rotating said traction wheels.

11. A turntable comprising main girders, wheeled trucks at the ends of said girders, said trucks being made in sections, and means connecting the truck sections, said means being arranged to permit of limited vertical movement While preventing relative horizontal movement of one end section relative to the opposite end section.

12. A turntable comprising main girders, a center bearin therefor, wheeled trucks at the ends of said girders, means connecting the trucks to the main irders, and arranged to permit of limited, re ative, vertical move ment and to prevent relative horizontal movement therebetween, and. means for rotating the turntable.

13. A turntable comprising main girders, a center bearing therefor, wheeled trucks at the ends of said girders, means connecting the trucks'to the main girders, said means 14. A turntable comprising main girders, gearing connecting said shaft to a truck a center bearing therefor, Wheeled trucks at Wheel, and a motor on said turntable for the ends of said girders, means connecting driving said shaft. re the trucks to the main girders, arranged to In testimony whereof I have hereunto set 5 permit of limited, relative, vertical movemy hand.

ment and prevent relative horizontal 1novement therebetween, a driving shaft, reducing LOUIS H. SHOEMAKER.

Copies 01 this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G."