US2649181A

US2649181A - Moving stairway

Info

Publication number: US2649181A
Application number: US30237A
Authority: US
Inventors: Hans E Hansen
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1948-06-01
Filing date: 1948-06-01
Publication date: 1953-08-18
Anticipated expiration: 1970-08-18

Description

Aug 18, 1953 H. E. HANSEN 2,649,181

MOVING STAIRWAY Filed June l, 1948 3 Sheets-Sheet 1 -/oorZ V1 l 2y /7 /25 OMM ,l

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ATTORNEY H. E. HANSEN MOVING STAIRWAY Aug. 18, 1953 3 Sheets-Sheet 2 Filed June l, 1948 /7005 E Hansen.

BW/wwf ATTORNEY A118- 18, 1953 H. E. HANSEN 2,649,181

MOVING STAIRWAY 3 Sheets-Sheet 5 Filed June 1, 1948 v lNvENToR Han5E/1an5en.

Blfewm ATTORNEY Patented Aug. 18, 1953 MOVING STAIRWAY Hans lE. Hansen, .New York, N. Y., assignor to Westinghouse Electric Corporation, lEast Pitts- -burgh Pa., a corporation of Pennsylvania Application June 1, 1948, Serial No. 30,237

(Cl. ISS- 16.)

29 Claims. 1

' This invention relates to conveyors and it has particular relation to moving stairways suitable for conveying passengers.

Moving stairways are employed widely for conveying passengers between diierent levels such as successive iioors of a building. Since these levels or floors 'vary in vertical lspacing over a substantial range, it is desirable that moving stairways be designed Tor readyaccommcdation to different vertical spacings of the successive floors.

The problem of adjusting a moving stairway to different floor heights is complicated by the fact that the stairway includes conveyor lchains for controlling the movement of a plurality of similar stairway steps. The .conveyor chains can be changed in length only by multiples of a dimen- .sion corresponding to the width of a stairway step. This dimension usually is of the order of 16 inches.

A moving stairway has an upper track assembly associated 'with upper sprocket wheels, a lower track assembly associated with lower sprocket wheels and an intermediate straight track assembly or portion which is inclined relative to the horizontal .at a predetermined angle, generally of .the order of 30.. Each of 'the track assemblies is associated with a part of a suplporting structure or truss. In prior art practice the upper track assembly has lbeen of standard construction for all installations. Also the straight portions of the track and truss have been of lstandard construction for all iioor heights, the only diierences -being in the lengths of these straight portions. However, the lower track assembly has been custom built for each installation in order to provide a spacing of the sprocket wheels and la. length of the tracks suitable for the required chain length for each stairway installation. Consequently, it has been impossible to stock lower track assemblies which :are available for all installations.

A further problem resides in the necessity for maintaining the stairway chains taut under all conditions of operation. In prior art practice, .this has .been eiected by mounting the lower sprocket wheels together with the associated parts of the tracks for movement asa unit with respect to the supporting structure. means are provided for biasing these sprocket wheels and the associated portions of the tracks in a direction suitable for maintaining the chains taut. Since the vprior practice required relative movement between portions of the tracks, suitable Sliding connections were 'provided for :the

Suitable y tracks. To assure continuity ofthe tracks for the stairway step rollers, dovetailed sliding'jfoints were employed .for the vrelatively movable track portions.

In accordance 'with the `invention the 'upper sprocket wheels of a moving stairway are constructed `for adjustment vrelative to vthe lower .sprocket wheels of the/moving stairway :for a distance capable of permitting ya change lin vthe .length of an associated chain corresponding to the width of one of the stairway steps. As previously pointed out, this distance usually is sufiicient to permit a change in the length of the chain of 1'6 inches.. Preferably, fthe adjustment is divided between the upper and lower sprocket wheels. By provision of the adjustment, it becomes possible to prefabricate in the shop complete standard upper'and 'lower track assemblies. The only change required 'to accommodate the stairway design vto different floorheights resi-des in the length of the straight truss and track 4portion of the stairway.

'The adjustment ofthe sprocket wheels is made substantially 'independent of the tracks 4employed for guiding the stairway steps around the Aaxes of the sprocket wheels. This permits the :adoption of a substantially continuous or endless track which'has rio-sliding or dovetailed joints.

In constructing a moving 'stairway according to the invention the tracks maybe installed complete except for small gaps between adjacent ends of the tracks. These small gaps may be accurately measured and fillers may be introduced therein which are secured directly to the adjacent track ends. This eliminates the Vformer practice of constructing long portions of the tracks to order with accurate ydimensions for each specific installation.

It is therefore an object of the invention to provide an improved `construction for moving stairways.

It is a furtherobject of the invention to provide a moving stairway wherein a flexible unit or chain operating around spaced wheels may have the wheels adjusted relative to each other for a distance sufficient to permit a change in the length of the flexible unit corresponding to the width of an associated stairway step.

It is also an object 'of the invention to provide a 'moving stairway as dened in the preceding paragraph, wherein the adjustment is divided between the sprocket wheels.

It is a still further object of the invention to provide a moving stairway havingsteps movable under 'the control of a yflexible unit operating about spaced Wheels and wherein tracks are provided for guiding portions of the steps about the axes of the wheels, at least one of the wheels being adjustable in a direction transverse to its axis relative to the associated portion of the track which guides the steps around the axis of the last-named wheel.

It is an additional object of the invention to provide a moving stairway employing upper and lower track assemblies which are prefabricated inthe shop as complete standard units.

A still further object of the invention corn- .prises the provision of a simplified track construction wherein a filler is introduced into a small gap between adjacent ends of a moving stairway track.

Other objects of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which:

Figure 1 is a view in side elevation with parts broken away and parts omitted, of a moving stairway which may embody the invention,

Fig. 2 is a view in perspective of the lower end of a moving stairway with parts broken away embodying the invention,

Fig. 3 is a view in sectional elevation of the lower end of the moving stairway illustrated in Fig. 2,

Fig. 4 is a detail view in side elevation of a portion of the lower end of the moving stairway illustrated in Fig. 2,

Fig. 5 is a detail view in sectional elevation taken along the line V-V of Fig. 3 showing securing mechanism for portions of the tracks employed in the stairway of Fig. 2,

Fig. 6 is a view in sectional elevation of the upper end of a moving stairway corresponding to that illustrated in Fig. l,

Fig. 7 is a detail view in side elevation showing mechanism for securing and adjusting the bearings for the sprocket wheel illustrated in Fig. 6,

Fig. 8 is a detail View in elevation showing a iiller construction suitable for the tracks of a moving stairway and Fig. 9 is a view in elevation of a iiller which may be supplied with a moving stairway.

Referring to the drawings, Fig. 1 shows a moving stairway for conveying passengers between two levels which are represented as floors I and 2 of a building. The moving stairway comprises an upper track assembly A, a lower track assembly B and a straight track assembly or portion C. As previously pointed out, the straight portion usually is inclined at an angle relative to the horizontal of the order of 30. Each track assembly includes track parts and parts of a supporting structure or truss which is not illustrated in Fig. l.

The moving stairway of Fig. l includes a pair of spaced wheels II and I3 which are mounted for rotation about parallel spaced axes. These wheels are employed for guiding an endless ilexible unit I5 in a continuous path. In customary practice the wheels II and I3 are sprocket wheels for guiding a flexible unit I5 in the form of an endless chain in a predetermined path.

The chain I5 has secured thereto a plurality of steps S. Each of the steps has a shaft I1 which passes through the chain I5 for movement therewith. Each shaft II carries a roller SI which is mounted for rotation with respect to the associated shaft and which is guided in a predetermined path by means of tracks I9 and 2|. As one of the shafts l1 reaches one oi the 4 sprocket wheels II or I3, it is received within the valley between successive sprocket teeth for movement about the axis of such sprocket wheel. Consequently, the sprocket wheels serve to transfer the steps between the tracks I9 and ZI. Each step also includes a roller S2 which cooperates with additional tracks represented by the track 23 in Fig. 1 for further guiding the steps. The rollers SI and S2 of a step are spaced in the direction of travel of the associated step.

Although a single exible unit or chain may be employed, in practice the shafts IIA and I3A which support the sprocket wheels I I and I3 are each provided with 'an additional sprocket wheel. The sprocket wheels on each shaft are spaced axially therealong. The additional sprocket wheels would have a chain similar to the chain I5 and this chain would be associated similarly with the steps S. Also, in common practice, each step S has a pairl of similar rollers at each end which cooperate in substantially the same manner with associated tracks. However, for the purpose of the present discussion it suflices to consider the parts associated with the single chain I5.

A conventional electric motor 25 is provided for rotating the shaft IIA in any suitable manner. For example, the motor 25 may be connected through reduction gearing to a sprocket wheel 21 which is coupled to a sprocket wheel (not shown) secured to the shaft IIA through a chain 29. Suitable motor control circuits for moving stairways are well known in the art. It may be pointed out further that the construction of the steps S and their association with chains may be in accordance with the teachings of the Dunlop Patent 2,085,076.

The vertical position of the shaft I IA is i'ixed by the floor 2. The vertical position of the shaft I3A is iixed by the floor I. The length L of the straight portion C of the tracks and associated truss is substantially determined by the height or distance between floors I and 2. However, the length of the chain I5 cannot be continuously varied. If it is necessary to shorten the chain, one of the steps may be omitted but the chain must then be shortened a distance corresponding to the width W of the removed step S or usually approximately 16 inches. As previously pointed out, the changes in the dimensions of the chain always must be multiples of this distance. As herein employed, the step width of 16" is the dimension of each of the steps S measured substantially in the direction of travel of a step as it reaches one of the sprocket wheels.

In prior art practice the track assembly A usually has been of standard construction. The construction of the tracks and the associated truss for the portion C of the moving stairway has been essentially standard except for the length -of the portion. The track assembly B has been custom built for each installation. To maintain the chain I5 substantially taut, it has been the practice to mount the shaft I3A slidably for movement in a direction suitable for maintaining the chain I5 taut. The shaft I3A may be biased in such direction by means of a spring 3|. In conformance with prior art practice, approximately l inch of movement of the shaft I3A is allowed for movement in either of two directions from a normal position to permit the chain l5 to follow any irregularities present in the tracks or associated sprocket wheels.

In accordance with the invention the sprocket Wheels Il and I3 are adjustable relative to each '5 other for a distance sumcient to accommodate a change 'in .the length of the chain corresponding to the width of one of the steps, which distance may be approximately 16 inches. Preferably, both of .the shafts IIA and I SAare adjustable relative to the associated supporting structure or truss to divide the lrequired, adjustment between the two .sprocket wheels `Ii and I3. A sui-table construction for the lower sprocket assembly may be understood more clearly by reference to Fig. 2.

Referring to Fig. 2 it will be observed that the shaft I3A has secured thereto not only the sprocket wheel I3 but an additional sprocket wheel IBB. vThese wheels are spaced axially along the shaft IBA. 'I'he chain I5 is guided over a substantial portion of the periphery of the sprocket wheel I3 and a similar chain V55B is guided in the same manner over the sprocket wheel I3B.

Only one of the steps f3 is illustrated in Fig. 2. It will be observed `that the rollers Si and S2 of this step are positioned for movement respectively along the upper tracks i9 and 2S. At its opposite end the step S similarly has two rollers SIB and SZB which are positioned for movement i respectively along tracks ISB and 23B which correspond to the tracks I9 and 23. Inasmuch as the chains I5 and IEB are guided for a substantial distance by their associated sprocket wheels I3 and I3B, the tracks I9 and I9B may terminate at points adjacent the sprocket wheels I3 and ISB at which the guiding function for the chains is taken over by the sprocket wheels. During the return movement of the step S the step rollers Si, S2, SIB and SZB are guided respectively by tracks ISC, 23C, I SBC and 23BC. For example the sprocket Wheel I3 transfers the roller SI between the tracks I9 and ISC. The other rollers are similarly transferred between suitable tracks.

To assure proper `transfer of the rollers S2 and S21-3 between their upper and lower tracks, these tracks overlap adjacent the associated sprocket wheels. It will be observed that the track 23 has an arcuate portion A23 which extends about the axis ofthe wheel I3 and has a portion B23 running for a substantial distance adjacent and above the track 23C. Similarly the track 23C has an arcuate portion A23C which extends about the axis of the wheel I3 and about the portion A23. In addition, the track 23C has a portion B230 extending for a substantial distance above the track 23.' It will be understood that as the step S descends, the roller S2 isv guided between the track portions A23 and AES'EC about the axis of the wheel 'I3 and is returned to the upper end of the moving stairway along the track 23C. The construction of the tracks associated with the sprocket wheel ESB represents an image or reflection of the tracks associated with the sprocket wheel i3 and these additional tracks cooperate with the wheel ISB to guide the associated rollers in substantially the same manner,

It may be noted further that the portions of the tracks A23, A25-2C, B23 and B290 and adjacent portions of the

tracks

23 and 23C all are secured to a plate 33 by welding or otherwise at the factory to form a complete standard unit. This plate has an opening permitting movement of the shaft iSA with respect thereto but may have a part represented by a rail 3d secured thereto which engages the top of the shaft H3A. Alternatively, the rail 3d may have an edge disposed within a circular groove extending around the shaft H3A which slidably supports the rail. It will be observed that the rail permits movement the bearing Il l.

'6 of the shaft IBA relative yto the plate 33 in Aa substantially horizontal direction. A similar plate 33B supports-corresponding portions of the tracks associatedwith the 3,sprocket wheel I3B in substantially the same'manner.

The plate or supporting-element 33 together with the associated portions of `the tracks secured thereto comprises a complete standard subassembly which may be constructed and stocked in any desired quantity. The same comment applies to the -subassembly represented by the `plate 33B and associated track, and to correspondingsubassemblies for the upper track assembly A which will be described below.

The tracks associated with the plate 33 may be adjusted angular'ly about the axis of the sprocket `wheel i3 in' any suitable manner. A preferred embodiment of the *invention is shown clearly in Figs. 3 and 5. The supporting structure for the stairway'has jack screws 35Bvsuitable `for adjusting the position of the tracks associated with the plate 33. Forfsimplicity all parts of the supporting structure or truss are identified by the Vreference character-ST. 'I'hus in Fig. 3 the supporting lstructure l includes a jack screw 35B `A which may-'be adjusted to move the plate 33 angularly about the axis'of the shaft 13A. After the plate has been lproperly adjusted it may be -securedfto the supporting structure, if desired, by means of bolts' 31 as-clearly shown in Fig. 5. Although the plate 33 could be left resting on the shaft ESA through the rail 34 it is believed preferable to attach it securelyto `the supporting structure after adjustment.

If parts of the supporting structure, such as a bracing member, are desired adjacent the plates, the -plates may lbe provided with `openings to permit passage of such parts. For example, the plates '33 and 33B have openings 36 and 36B through which a bracing member 36C may pass. Such a bracing 'member' would be removably bolted to the supporting structure ST by means of bolts 36D.

Returning to Fig. 2, it will be observed that one end of the shaft 13A is mounted for rotation in a bearing MB. This bearing is mounted on rollers 43B for movement in a horizontal direction along a platform 45B which is secured to the supporting structure. A spring SIB is compressed between the supportingstructure and a washer MB which surrounds a stud i913 projecting from Such compression 'may be adjustably provided by means of a nut 5IB which engages a threaded end of the stud. Because of this construction the spring biases the bearing 4 IB in a direction tending to maintain the chain 45Br taut. The opposite end of the shaft I 3A similarly is `mounted vfor rotation in a bearing 4I (Fig. 4 9 which is biased in the same direction by means of a stud 49 and the spring 3|. The bearing is mounted on rollers d3 which move on a horizontal platform 45. 'After the normal position of the shaft I3A is determined one or more stops d8 may besecured tothe supporting structure for limiting excessive movement of the shaft.

It will be recalled `that the invention contemplates a substantial range of'adjustment for the sprocket wheels with respect to the supporting structure.' For example, the'shaft ISA may be adjusted in ahorizon'tal direction'over a total distance D (see Fig. 3). If the length of chain required for each step is 16 inches the distance D may be 4 inches. A`Sincemovement of the sprocket wheel ISB Vaffects both the .upper'and lower runs of tnechain the adjustment ofthe shaft l:3A for a distance of 4 inches permits a change in length of the chain of 8 inches. If the sprocket wheels at the upper end of the moving stairway may have their axis adjusted for a similar distance of 4 inches it follows that the combined adjustments permit a change in length of the chain of 16 inches. It will be recalled that the lower sprocket wheels must have an additional range of movement of the order of il/z inch from a normal position to accommodate Variations in the chain length resulting from irregularities present in the moving stairway.

Referring to Fig. 3 it will be observed that the adjustment of the sprocket wheels and the shaft ISA for the desired distance D does not affect the position of the tracks in any way. Consequently, a 4substantially endless fixed resultant track may be presented to the rollers SZB as they pass about the axis of the shaft ISA. The effect of adjustment of the shaft I3A relative to the associated tracks is to change the tilt of the steps as they travel about the axis of the shaft. The limits of adjustment of the shaft ISA in Fig. 3 are represented respectively in full and broken lines. Similarly the positions of the steps S as they move about the axis of the shaft ISA corresponding to the two limiting adjustments of the shaft are represented in full and broken lines. It will be observed that the change in tilt of the steps is effected without requiring any substantially increased space.

It will be understood further that after the normal position of the shaft ISA is established the ends of the tracks i9, ISB may be cut to the proper dimension. These tracks may be constructed at the factory with the maximum dimension required. After the normal position of the shaft I3A is determined, the ends of the tracks may be cut or bent as required. Similar comments apply to the short tracks 55 and 55B which are positioned respectively above the tracks ISC and ISBC adjacent the lsprocket wheels I3 and I3B to assist in guiding the rollers SI and SIB. For example, in Fig. 3 as a sprocket wheel rotates in a counterclockwise direction the rollers SIB, as they leave the sprocket wheel, are received between the tracks I9BC and 55B.

The upper track assembly A is illustrated in Fig. 6. In general the same principles of construction may be followed. for both of the track assemblies A and B. The shaft IIA carries at one end the sprocket wheel II (Fig. l) and at the opposite end a sprocket wheel IIB (Fig. 6). These wheels cooperate respectively with the chains I and IEB for guiding the steps S between the upper and lower tracks. It will be noted that the track 23B has a portion 023B which is secured to a plate 59B. This plate has a rail BI secured thereto which rests on the shaft IIA in the manner discussed with reference to the rail 3@ of Fig. 2. The plate 59B of Fig. 6 may be adjusted angularly about the axis of the shaft IIA by means of a jack screw 63 which is in threaded engagement with the supporting structure ST and which engages the lower side of the track 023B for adjusting the plate 59B angularly with respect to the shaft IIA. After the plate 59B has been adjusted it may be secured to the supporting member in the manner discussed with reference to the plates in the lower track assembly.

The lower track 23BC also has a portion CZSBC secured to the plate 59B. This portion has an arcuate section D23BC which extends angularly about the shaft IIA and merges into a 8 straight short section of track E23BC. In a similar manner the portion of the track 023B merges into an arcuate section D233 which is substantially concentric with the section DZSBC. The arcuate section D23B merges into a short section of track E23B which is parallel to but spaced from the section C23BC. It will be understood that as the sprocket wheel IIB rotates in a clockwise direction, step rollers S'B (which are directly behind the rollers S2 in Fig. 6) are carried up the portion 23BC of the track adjacent the sprocket wheel IIB. The step rollers SZB are guided between the track portions E23B and C23BC until they enter the space between the arcuate sections DZEB and D'ZZSBC'. As the steps are carried about the periphery of the sprocket wheel IIB, the rollers SEB are guided into the spaces between the track sections C2 3B and E23BC. They then continue down the track 23B. It will be noted that a substantially fixed continuous resultant track is provided for the rollers S2B. A somewhat similar set of tracks which is a reflection or image of the set of tracks just described, is provided in the upper track assembly for the rollers S2. The relationship of these two sets of tracks is similar to that discussed for the lower sprocket assembly.

As the steps are carried about the upper sprocket wheel the axles of the step rollers SI and SIB are received successively in valleys between successive teeth of the upper sprocket wheels. The tracks IBB and ISBC may terminate adjacent the upper sprocket wheel IIB. Auxiliary guide tracks 64 and 65 may be included in the upper track assembly for cooperation with the tracks ISB and I9BC respectively to guide the step rollers SIB. These auxiliary tracks also may terminate adjacent the sprocket wheels of the upper track assembly. The construction of the tracks for the step rollers SI will be understood from the discussion of the tracks for the track rollers SIB.

It will be understood that the upper sprocket wheels together with the shaft IIA preferably are adjustable in a horizontal direction for a substantial distance D. The bearing assembly for the shaft IIA may be essentially similar to that employed for the shaft ISA. However, it suffices to provide a biasing arrangement for the lower sprocket assembly alone and for this reason provision is made for securing the bearings of the shaft IIA in any adjusted position.

A bearing assembly suitable for the shaft IIA is illustrated in Fig. 7. As shown in this figure, a bearing 69 is provided which is slidable with respect to a platform Il secured to the supporting structure IST. The position of the bearing with respect to the platform may be adjusted by means of a stud 'I3 which projects from the bearing in a horizontal direction through a portion of the supporting structure ST. Nuts 'i5 are positioned on the stud I3 on each side of the associated portion of the supporting structure ST. The stud together with the associated bearing may be adjusted as desired in a horizontal direction. After adjustment the bearing may be secured rigidly to the platform 'II by means of bolts 'I'I which pass snugly through openings in the bearings and which pass through suitable slots (not shown) in the platform 'EL These slots permit adjustment of the bolts in a horizontal direction for the desired distance. It will be understood that a similar bearing assembly is provided for each end of the shaft I IA.

When the desired position of the shaft HA is established the adjacent ends of the tracks 19B,-

ISBC, Gil and 65 may be cut or bent' as desired in order to guide the associated step rollers to best advantage. It will be understood that the tracksare made sulciently long forv .the maximum movement of the shaft ITA to the left as viewed in Fig. 6.

vThe shaft l A may be adjustable over any suitable range. Under the conditions herein assumed, the shaft HA is made adjustable in a horizontal direction for'a distance D o'f 4 inches'. Since this adjustment aiects both the' upper and' lower runs of the chains the adjustment of the' shaft l A is sufficient to accommodate a change' in chain length of 8 inches. inasmuch' as' the lower sprocket wheel shaft has' ai similar adjustment, the combined adjustments are sufficient' for a total change in chain' length of 16' inches'. The positions of the shaft' HA and of the' steps" S, when they occupy their limiting" positions", are illustrated in Fig. 6' respectively by full' and' broken lines.

In computing the dimensions o'f a stairway constructed in accordance with' the invention, it may be assumed that the shafts I'A and H3A are each located at the midpoint of the" respective range of adjustment thereof. The length of the straight portion C of` the' track and truss assembly is determined bythe distance between the doors served by the stairway. The stairway is then provided with that number' of steps which provides a chain length closest' to' that required for the assumed initial positions of the shafts HA and H3A. The chain length having been determined, the shafts II and |'3'A ,may b'e adjusted to the pcsitionsrequired for the chain length so determined.

As shown in Fig. 6 the4 track 23B may be attached to the track portion 023B in any suitable manner as by placing the track ends in abutment and welding or otherwise securing a plate 8i to both of the ends' onthe lower side of the track. The tracks 2"3BCy and ISBC simi'- larly may be attached to the related track portions of the upper track assembly.

In prior art practice it has been the custom tov calculate carefully the required length of track in the straight portion C of the stairway. Since it is virtually impossible in practice to have the ends of the tracks of the portion C snugly abut the ends of the correspondingtracks inthe track assemblies A and B' thev proper' fitting of the adends of the tracks hasA` required' appreciable and difficult fieldtting.

According to the invention the portions ofthe stairway are calculated to provide tracks which, when fitted. together, have' gaps'ofsmall: dimen-` sion, say 1 inch. The portions orC theistairway' assembly then may be secured to each' other in the eld. Because of tolerances torb'e expectedy in manufacture and in installation, the resulting gaps may be more orv less" tharr thel 1 inch initially allowed. However, a filler F' is provided for lling each oi the gaps. Thevcon'struction of the niler will be understood from aA consideration of Figs. 8 and 9.

Referring to Fig. 9 it will' beobserved tha'tthe iiller is of T formation. The lupper bar FI? off the filler is intended to torniL part off therunway of the track with' which-:it isI associated. The stem F2 of the ller is aspacerfor spacing' the filler F from a supporting-` plate18'5-(Eig1; 81) The stein has one or more studs F3 projectingtherefrom which pass through.' the? pl'ate'v85`i andi which are secured thereto'by'meane ofi suitable nuitslelf and washers 89.

It will be assumed that the track ends Tl and T2 were intended to be approximately 1 inch from each other, but because of the aforesaid tolerances, the tracks following installation of the stairway of which they are a part, have a gap therebetween of 1% inches'. The ller F has a bar length Fl sufficient' to take care of the maximum gap which may" be encountered in practice. When a track is completely installed except for the gap to be lled by the filler, the is accurately measured and the ends of the bar Filk are cut to the proper dimension (represented by dotted lines in Fig. 9) to fill the gap.

The iiller El together with the track ends TI and?? are secured to the plate 65 in a convenient manner as by bolting the various parts' to the plate. cured by the stud F3 and the nut 87. The ends Ti and TE." have welded thereto spacers 9| and tfrespectively. Each ci' the spacers has one or more studs 9'5- projecting therefrom. The plate S5" is provided with openings permitting passage therethrough. of the studs 95. Nuts Sl and washers e9' are provided for the studs S5 to secure the plate 85 rigidly to the spacers 9i and S31 The parts are so constructed that the filler F completely fills the gap between the track ends and' forms therewith a continuous track surface for the rollers.

rihe nominal gap length to be allowed between track ends for reception of the filler F may be selected from a substantial range. For example, a nominal g'ap of l inch is generally within reasonable tolerances. To take care oi the expected eld variations in' the nominal gap, the ller F may' have a length of the bar Fl of the order of 3 inches. The provision of the filler F materially simplifies' the construction of the tracks and supporting structure.

It is believed' that the operation and' installation of a' complete system now may be set forth'. l't'will be'under'stood that the upper track assembly A and the lower track assembly B may be constructed and stocked as standard items substantially' of the design illustrated in Figs. 2, 3, 4, 6- and 7. The straight portion C of the moving stairway assembly isvv of standard construction except for the required length. When an order is received for a stairway for operation' between two floors, oneof the upper track assemblies and one ofthe lower track assemblies are allocated for' th'e order. The designer then assumes that tliesh'a'fts IIA and 53A are located in their associated track assemblies in their median positions of adjustment. Knowing the distance between the oors. the designer computes the' length` of the straight portion C of the stairway. The computations are such that gaps having a no'r'ninal dimension, such as l inch, are left between the tracks of the straight portion C and the' associated tracks of the lower track assembly B for reception of the nllers F.

The designer next computes the length of chain" required for the assumed positions of the sprocket wheels. if such a chain is not oi properl'ength for an integral number oi steps S the chain is lengthened or shortened by the smallest dimension required for an integral number of step's.- For example, let it be assumed that the chain as computed has a length suitable for receiving 30% steps. The designer then adopts a shorter chain having a length suitable for exactly- =steps or al cha-in 2 inches shorter than the chain called for by the initial assumptions. To adlju's't the stairway for the shorter chain the shaft' linkin-Figa 6- would be moved 1/2 inch to- As shown in Fig. 8 the' filler F is se- 1l the right from its median position and would be secured rmly in such position. If necessary for the new position of the sprocket wheels, the ends of certain of the tracks terminating adjacent the sprocket wheels may be bent or cut as required.

The various parts are installed in the building for which they are designed and ller blocks F are provided forv the gaps adjacent the lower sprocket assembly. It will be recalled the nomin al gaps of l inch are allowed to care for manufacturing and installation tolerances. Let it be assumed that one of the gaps 'has a final value of 11/2 inches whereas the remaining gaps have values of 11/8 inches. Three filler blocks have their bars cut to iill accurately the gaps. They are then secured in position in the manner shown in Fig. 8.

Following installation of the various stairway parts the springs 3| and SiB are adjusted by manipulation of their associated nuts to provide the desired tension on the shaft i3A. This tension maintains the shaft approximately in a position 1/2 inch to the left of the median position of the range in adjustment of the shaft IBA as viewed in Fig. 3. However, it will be understood that the springs are intended to permit a reasonable range of movement of the lower shaft ISA such as il/g inch to maintain the chains taut as they follow the irregularities in the stairway guiding structure. The range of movement allowed the lower shaft is suicient to take up the initial wear in the chain as the chain links seat themselves on their bearings. Excessive movement of the shaft 13A in a horizontal direction may be employed for actuating a conventional safety switch (not shown) in the manner disclosed in the Dunlop Patent 2,081,989.

During installation it will be recalled that the various track supporting plates such as the

plates

33, 33B, 59 and ESB may be adjusted angularly about their associated shafts by operation of the jack screws provided for this purpose. After suitable adjustment, each of the plates may be secured to the supporting structure for the moving stairway.

Although the invention has been described with reference to certain specific embodiments numerous modications thereof are possible falling within the spirit and scope of the invention.

I claim as my invention:

l. in a moving stairway, a supporting structure, an endless flexible unit, a guide for the flexible unit comprising a wheel mounted for rotation relative to the supporting structure for guiding the flexible unit about the axis of the wheel, a stairway stephaving a nrst portion secured to the flexible unit for movement therewith, and a guide substantially fixed relative to the supporting structure for guiding a second portion of the stairway step as the iirst portion passes about the axis of the wheel in a path spaced from the path of the first portion, the axis of the wheel being adjustable relative to the guide in a direction substantially transverse to the axis of the wheel for a substantial distance.

2. A moving stairway as dened in claim l in combination with mechanism for releasably retaining the axis of the wheel in adjusted positions.

3. A moving stairway as defined in claim 1 in combination with a biaser for resiliently biasing the axis of the wheel in a direction substantially transverse to said axis.

4. In a moving stairway, a supporting structure, a pair of wheels mounted for rotation relative to the supporting structure, said wheels having substantially parallel, `spaced axes, an endless iiexible unit engaging the wheels for movement thereabout in a predetermined circuitous path, a stairway step engaging the exible member for movement thereby around the circuitous path, a guide substantially iixed relative to the supporting structure for guiding a portion of the stairway step during the travel of the step about one of the spaced wheels in a path spaced from said circuitous path, and adjusting means for adjusting the position of the last-named wheel in a direction substantially transverse to the axis of the last-named wheel relative to said guide.

5. In a moving stairway, a supporting structure, a pair of wheels mounted for rotation relative to the supporting structure, said wheels having substantially parallel, spaced axes, an endless flexible unit engaging the wheels for movement thereabout in a predetermined circuitous path, a stairway step having a first portion engaging the exible unit for movement thereby around the circuitous path, a guide substantially xed relative to the supporting structure for guiding a portion of the stairway step displaced from said first portion during the travel of the first portion around each of the wheels, and separate adjusting mechanism for adjusting the position of each of the wheels relative to the guide in a direction substantially transverse to the axes of the wheels.

6. A moving stairway as defined in claim 5 wherein the adjusting mechanism comprises a fastener for fastening a rst one of the wheels in adjusted position, and a biaser for resiliently urging a second one of the wheels in the proper direction for maintaining the flexible unit taut.

1'. ln a moving stairway, a stairway step, a substantially endless fixed track for guiding a part of the stairway step in an endless path, an endless chain engaging a part of the step spaced from the first-named part for controlling the movement of the step about said fixed track, a guide for the chain comprising a sprocket wheel having a substantial peripheral portion substantially spaced from the iixed track and engaging the chain, said wheel being mounted for rotation relative to the fixed track, said track having a portion extending around the axis of the wheel, the radii of the wheel and said portion being substantially different, and adjusting mechanism for adjusting the sprocket wheel relative to the xed track in a direction transverse to the axis of the wheel.

8. A moving stairway as defined in claim 7 wherein a shaft extends through the loop formed by the endless xed track for supporting the wheel, said shaft and wheel having clearance relative to the xed track to permit movement of the shaft and wheel in a direction substantially transverse to the wheel without disturbance to said fixed track.

9. AV moving stairway as defined in claim 3 wherein the fixed track has a portion substantially concentric about a second axis, the` wheel axis and the second axis being parallel and adjacent each other, said adjusting mechanism being operable for adjusting the spacing between said axes, said track and the chain engaging separate portions of the step which are spaced from each other in the direction of movement of the step.

10. In a moving stairway, a supporting structure, a wheel mounted for rotation about an axis relative to the supporting structure, an endless acidic-1.

flexible unit having a part engaging a substantial portion of the peripheral portion of the wheel for guiding the endless flexible member continuously about the wheel axis, a. step engaging the flexible unit for movement therewith, a track having a substantially-.listed position relative to the supporting structure; said track having a portion curved about the axis' of the wheel for guiding a part of the step around said axis, said Wheel having a circular part secured thereto concentrically about the axis, said track having. a member tangentially engaging the circular part for supporting the track and permitting adjustment of the wheel relative to thetrack in a direction transverse to the axis.

1l. A moving stairway as. deiined in claim 1G. in combination with adjusting mechanism adjusting the track relative tof the supporting structure angularly about said 12. In a moving stairway, a track having two track ends defining a gap', .a filler in said gap for providing a continuous track surface, said ller having a T-section in a plane intersecting the track ends and perpendicular tothe track surface, and a plate bridging, the: gap and secured to said filler and to' each of the track ends for maintaining the iiller in position.

13. In a moving stairway, a rotating element, a supporting element, a track memberl secured to the supporting element, said track member having a portion arcuate about a-n axis4 parallel to, and adjacent the axis of the` rotating element through an angle of approximately 180, and adjusting mechanism for adjusting the supporting element angularly about the axis of the rotating element.

14. A moving stairway as defined in claim 13 wherein the track member has ends extending tangentially from said arcuateI portion for substantial distances, said ends and arcuate portion being rigidly secured toA the supporting element.

15. A moving stairway as defined in claim 1.3, wherein the supporting. element hasa part slidably engaging the rotating element.

16. In a moving stairway, a supporting structure, a rotating element mounted for rotation relative to the supporting structure, a supporting element, a pair of concentricr tracks arcuate for substantially 180 about an axis parallel to, and adjacent to the axis of the rotating element, said tracks being secured rigidly to ther supportingv element to form therewith a self-sustaining unit, mechanism for directing a stairway step about the rotating element, said step having a part, positioned between said concentric tracks during said direction of the stairway step about the. ro tating element, said supporting element. being secured rigidly to the supporting structure, and means for adjusting the. position of the. rotating element relative to the, supporting element andi the tracks.

1'7. In a moving stairway, a track providing a tracking surface, said track having track ends dening a gap, a T-shaped ller including a bar and a stem substantially at right angles to each other, said bar having a first dimension substantially iilling the gap to provide with thek track a substantially continuoustracking surface, the corresponding dimension of the stem being less than the first dimension,` and., means securing the stem to the track ends.

18. A moving stairway asy claimed in claim 1'7 wherein said track ends have back surfaces substantially parallel to and. spaced. from the tracking surface, said securing. means including. a

14 member adjacent said back surfaces and said stem, and means securing the track ends and the stem securely to the-member.

19. In a moving stairway, a plurality of independently-mounted track assemblies, one of the track assemblies comprising a supporting element, a track secured to the supporting element, said track including a portion arcuate for substantially about an axis, and portions forming extensions of the ends of said arcuate portion, said extensions approaching each other at positions displaced from the arcuate portion, the supporting element having an opening through which said axis extends, whereby a shaft may be passed through the opening, and a rail secured to the supporting element and extending at least partially across the opening in a direction substantially transverse to said axis, whereby the rail may rest on a shaft passing through the opening.

20. A moving stairway having a supporting' structure, a pair of endless chains, said chains being located in parallel, spaced planes, an endless series of steps located between the chains,

each of said steps being pivotally secured to each of the chains for rotation about a pivoting axis relative to the chains, a separate pair of spaced chain rollers rotatably secured toeach of the steps for rotationr about the pivoting axis of the asssociated step, a pair of spaced rst sprocket wheels disposed for rotation relative to the supporting structure about a -rst sprocket wheel axis for engaging respectively said chains to reverse the direction of travel thereof, first mounting means mounting the sprocket wheelsfor rotation about said rst sprocket wheel axis, a pair oi spaced second sprocket wheelsI disposed for rotation relative to the supporting structure about a second sprocket wheel axis for engaging respectively said chains to reverse the direction of travel thereof, second mounting means mount-- ing the second sprocket wheels for rotation` about the second sprocket Wheel axis, said sprocket wheel axes being parallel and being located respectively adjacent the ends. of the stairway, and a pair of spaced step rollers for each of the steps mounted for rotation about av step roller axis which is parallel to, and spaced from the pivoting axis of the same step, track means for guiding said step rollers. in paths.

spaced from the paths. of the. chains as the steps move about the sprocket wheel axes, the track means and the supporting structure having suflicient clearance to permit adjustment of the sprocket wheel axes relative to each other and' relative to the track means by a distance corresponding to the change in the lengths of the chains required to change the number of steps by one.

21. A moving stairway as` claimed in .claim 20 wherein each of the sprocket wheel axes is adjustable relative to the supporting structure and relative to the track means for substantially one-half of said distance.

22. A moving stairway having a supporting structure, a pair oi endless chains, said chains being located in parallel, spaced planes, an endless series of steps located between the. chairs, each of said steps being pivotally secured to. each of the chains for rotation about apivoting axis. relative to the chain, a separate pair `of spaced. chain rollers rotatably secured to each of the steps for rotation about the pivoting axis of` the associated. step, a pai-r of spaced rst sprocket. wheels disposed for. rotation. re1ative. to. the sup.-

porting' structure about a first sprocket wheel axis for engaging respectively said chains to reverse the direction of travel thereof, iirst mounting means mounting the sprocket wheels for rotation about said sprocket wheel axis, a pair of spaced second sprocket wheels disposed for rotation relative to the supporting structure about a second sprocket wheel axis for engaging respectively said chains to reverse the direction of travel thereof, second mounting means mounting the second sprocket wheels for rotation about said second sprocket wheel axis, said sprocket wheel axes being parallel and being located respectively adjacent the ends of the stairway, and a pair of spaced step rollers for each of the steps mounted for rotation about a step roller axis which is parallel to, and -spaced from the pivoting axis of the same step, in combination with adjusting mechanism operable for adjusting the spacing of the sprocket wheel axes for a substantial distance, and track means for guiding said step rollers substantially continuously during continuous rotation of said sprocket wheels, said track means providing sufficient clearance for the sprocket wheels and the mounting means to permit said adjustment of the sprocket wheel axes without disturbing the position of the track means.

23. In a moving stairway, a track assembly comprising a supporting element, a track unit comprising a track portion arcuate for substantially 180 about an axis, said track unit having an opening through which the axis extends, whereby a shaft may be passed through the opening, and a rail secured to the track unit and extending at least partially across the opening in a direction substantially transverse to the axis, whereby the rail may rest on a shaft passing through said opening.

24. In a moving stairway, a supporting structure, an endless exible unit, a guide for the flexible unit comprising iirst and second wheels mounted for rotation relative to the supporting structure respectively about first and second spaced axes for guiding the exible unit in an endless path about the axes, a plurality of stairway steps distributed around the flexible unit, each of the stairway steps having a rst portion engaging the iiexible unit for movement therewith, and a guide substantially fixed relative to the supporting structure for guiding `a portion of each of the steps about each of the spaced wheels in a path spaced from the path of the first portion, the axis of each of the wheels being adjustable relative to the guide in a direction substantially transverse to the axis of the associated wheel for a substantial distance.

25. A moving stairway as claimed in claim 24 wherein the combined ranges of adjustment of the wheels is suicient to permit a change in the length of the endless flexible unit by `a distance corresponding to the width of one of said stairway steps.

26. In a moving stairway, an upper stairway assembly including a iirst supporting structure, a first wheel, rst bearing means mounting the first wheel on the supporting structure for rotation about a first axis, rst guide means mounted on said supporting structure, said supporting structure and guide means having clearance permitting adjustment of the bearing means and iirst wheel in a direction transverse to the axis for a predetermined distance, a lower stairway assembly including a second supporting structure. a second wheel, second bearing means mounting the second wheel on the supporting structure for rotation about a second axis spaced from, and parallel to, the first axis, second guide means mounted on the supporting structure, said second supporting structure and second guide means having clearance permitting adjustment of the second bearing means and second wheel in a direction transverse to the second axis for a predetermined distance, an endless flexible unit for engaging the wheels and extending therearound in a circuitous path, a plurality of stairway step units distributed around the flexible unit and engaging the flexible unit for movement therewith about the circuitous path, said rst guide means being positioned to engage and guide a portion of each of the step units spaced from the flexible unit as the engaged step unit moves about the first wheel, said second guide means being positioned to engage and guide a portion of each of the -step units spaced from the flexible unit as the engaged step unit moves about the second wheel, the sum of the predetermined distances being sufficient to permit a change in length of the flexible unit corresponding to the width of one of the steps, and means for securing the bearing means in adjusted positions to the supporting structures.

27. A prefabricated stairway track assembly for location at one end of a moving stairway to guide the steps of a moving stairway as the steps leave and approach the inclined run of the moving stairway extending between the floors served by the moving stairway, said track assembly comprising a substantially ilat supporting element, and a track secured to the supporting element, said track having an arcuate part extending arcuately for an angle of substantially about an axis transverse to the supporting element, a first extension extending from a first end of the arcuate part substantially parallel to said supporting element, said first extension having a straight part adjacent the arcuate part and having an end part inclined relative to the straight part by an angle of substantially 30, and a second extension extending from a second end of the arcuate part, said second extension having an end part substantially parallel to said rst-named end part.

28. A prefabricated stairway track assembly for location at one end of a moving stairway to guide the steps of a moving stairway as the steps leave and approach the inclined run of the moving stairway extending between the floors served by the moving stairway, said track assembly comprising a substantially nat supporting element, and a track secured to the supporting element, said track having an arcuate part extending arcuately about an axis transverse to the supporting element to reverse the direction of the track, said track having extensions extending from the ends of the arcuate part, said extensions including a straight part, whereby the straight part may be positioned in a horizontal plane to guide steps of a moving stairway horizontally adjacent one end of a moving stairway, said extensions approaching each other adjacent their ends and terminating in substantially parallel ends which are inclined relative to the straight part.

29. A pair of prefabricated stairway track assemblies for location at one end of a moving stairway to guide the steps of a moving stairway as the steps leave and approach the inclined run of the moving stairway extending between the floors served by the moving stair- 17 Way; each of said track assemblies comprising a substantially at supporting element, and a track secured to the supporting element, said track having' an arcuate part extending arcuately for an angle of substantially 180 about an axis transverse to the supporting element, a first extension extending from a rst end of the arcuate part substantially parallel to said supporting element, said first extension having a straight part adjacent the arcuate part and having lan end part inclined relative to the straight part by an `angle of substantially 30, and a second extension extending from a second end of the arcuate part, said second extension having an end part substantially parallel to said rstnamed end part; said tracks dening similar, spaced, parallel paths and being located substantially between the supporting elements when the supporting elements are opposite each other. HANS E. HANSEN.

References Cited in the le of this patent UNITED STATES PATENTS Number Number Name Date OKeeffe May 2, 1876 Weber Aug. 4, 1903 Burns Feb. 12, 1929 Bush Mar. 26, 1929 Valtier July 26, 1932 Lindquist Apr. 24, 1934 Lindquist et al. Dec. 18, 1934 Cooper Oct. 1, 1935 Shonnard Oct. 6, 1936 Harman Apr. 23, 1940 Dunlop Feb. 11, 1941 FOREIGN PATENTS Country Date Germany Aug. 30, 1933