US2349315A - Air circulating system for refrigerator cars and the like - Google Patents

Description

AIR CIRGULMEING SYSTEM FOB: REFRIQEYATOR CARS AND THE LIKE N. W 9 D Wu E a Sheets-Sheet 1.

July 9, 3.949

' [12.0822 for. hlliamil ilzfiariz,

M y23,1 w. E. VAN-BORN 2,349,315.

AIR CIRCULATING SYSTEM FOR REFRIGERATOR CARS AND THE LIKE Filed July 9, 1940 5 -Sheets- -Sheet 2 71* 83 6 6 I 66 lave/252a): h'llim'izii 7001 0272. 6 7.7 73

May 23, 1944. w. E. VAN DORN 2,349,315

AIR CIRCULATING SYSTEM FOR REFRIGERATOR CARS AND THE LIKE Filed July 9, '1940 5 Sheets-Sheet 3 I \w 0. mm

May 23, 1944.

w. E. VAN DORN AIR CI RCULATING SYSTEM FOR REFRIGERATOR CARS AND THE LIKE Filed July 9, 1940 5 Sheets-Sheet 4 11206320)". mlliam E K212120212.

Patented May 23, 1944 Am cmoum'rmo SYSTEM FOR REFRIGER- ATOR cans AND THE LIKE William E. Van Dorn, Pasadena, CaliL, assignor to Pacific Railway Equipment Company, Los Angelcs, Calif, a corporation of California Application July 9, 1940, Serial No. 344,509

(01. s ss) 3 Claims.

This invention refers to improvements in air circulation in transport vehicles. The invention is capable of general application to transport vehicles wherever air circulation is desired. But it has been designed particularly with reference to refrigerator cars and will therefore be described typically and illustratively in that application and unit and its mounting and disposition relative to the car, and in the driving means for the unit. Although the driving means has particular utility in combination with the improved air impeller unit, it is also useful for driving any usual car accessory.

The detailed objects and accomplishments of the invention will best be gathered from the following description of preferred and illustrative forms of the system, and their functions. However, I may mention preliminarily that the improved system and devices of the present inventlon, have advantages, among other things, in

their easy adaptability and applicability to refrigerator cars of all types and kinds, in efllciency of operation, in freedom from necessity of frequent service, in ease of servicing, and in adap tability to being driven either from the running gear of the car or by independent power.

In the accompanying drawings: Fig. 1 is a fragmentary transverse section illustrating one form of my improved system applied to a refrigerator car, this view being taken as indicated by line i--l onFig. 2;

Fig. 2 is a longitudinal section and side elevation of the parts shown, in Fig. 1, being taken in the aspect indicated by line 2--2 of Fig. 1;

Fig. 3 is a section taken on line 33 of Fig. 1; Fig. 4 is a detail section taken one line 4-4 of Fig. 1;

r Fig. 5 is an enlarged detail section taken on line 5--5 of Figs. 2 and 4; f

Fig. 6 is a diagrammatic section taken asjndicated by line 6--B on Fig. 3;

Fig. 6a is a section similar to that of Fig.6 and showing a modified form of traction roller for the driving mechanism;

Fig. 7 is a plan, partially broken away in section, showing the structure and disposition of the air impeller unit which is shown in Fig. 1;

Fig. 8 is'a transverse section, similar lnaspect to the transverse section of Fig. 1, and taken as indicated by line 8-8 on Fig. 9, showing a modifled form of driving mechanism;

Fig. 9' is a fragmentary longitudinal section taken on line 98 of Fig.8;

Fig. 10 is a longitudinal section taken on line Ill-Ill of Fig. 8; V

Fig. 11 is an enlarged detail section in a substantially horizontal plane taken on line ll-il of Fig. 10;

Fig. 12 is an enlarged detail section taken line l2-l2 of Fig. 9;

Fig. 13 is an enlarged transverse section taken as indicated by line l3--|3 on Fig. 2 and showing the application of the independent driving motor;

Fig. 14 is a section taken as indicated by line I4 H on Fig. 13.

Referring first more particularly to Figs. 1 3 and 7 I will first describe the improved formof air impeller unit and its disposition with relation to a car body. In these figures the car floor is indicated at 20, the two side walls at 2| and the ice bunker wall at 22. In typical refrigerator car construction there is an opening at 23 at the lower part of bunker wall 22, of a height about equal to the height of the lading floor above the car'floor, and extending across the width of the car. The typical refrigerator car has two such ice bunker walls at opposite ends, and there are openings, similar to 23, in the upper portions of the bunker walls. The lading floor. is usually in the form of a rack or racks having floor slats 24 supported on stringers 25 that rest on the car floor. And it is common practicethat the floor racks are divided longitudinally at the center of the car, as indicated by the gap shown at 21 in Fig. 7; the two racks being hinged to the sides of the car, as indicated at 28 in that figure. It is desirable that the floor racks be liftable for cleaning and other purposes, and my impeller unit fully accommodates that desirable operation, as will be seen. In applying my improved system to a car I preferably use two impeller units 3%, each with its independent driving mechanism, in a position substanltally over a truck or substantially over one of the wheel and axle units of a truck. The l0cationof each impeller unit is therefore somewhat near an end of the car, and the two impeller units, acting in concert, set up a circulation throughout the whole interior of th car body. Each of the impeller units is installed in the space between the impelling units may move the air in opposite directions between the two floors. Thus each impelling unit may act to draw air from the lower end of the adjacent ice bunker and impel it between floors toward the center of the car. The air then rises throughout the load and the central portions of the car and, in a double circulatory 1 path, passes then to the upper parts of the ice bunkers and then downwardly through them. Without any limitation upon the invention this latter described circulatory path is the one which I think preferable. And when the impelling units are arranged for that type of circulation, the impelling units are not only coimter-parts of each other. but, in their functions, are symmetric counter-parts. A description of one such unit; its mounting and disposition and its driving mechanism is therefore suflicient to a complete understanding of the invention.

In connection with what is said in the immediately foregoing I call attention to the fact that my improved system, and particularly the impeller units, are of such name that they always move the air in the same directions with reference to the car regardless of the direction of car travel. The most effective circulatory paths may thus be chosen to suit the particular circumstances, the system may be installed to obtain the directions of circulation thus chosen, and the circulation directions will then remain unaffected by the direction of car travel.

The impeller unit includes a casing made up of a bottom plate 35, discontinuous side walls 35. and transverse partitions 31, which side walls and partitions are made up of bent metal sheets in a manner which will be understood from inspection of Fig. 7. The side walls and partitions are secured to the base plate by welded flanges 38. The arrangement is such that alternate spaces are provided between the several pairs of adjacent partitions for the reception of air impellers 39. Each of these impeller-receiving spaces is open at one side of the casing and closed by side wall 36 at the other side. In Fig. 3 the open side is to the right and in Fig. '7 at the top of the figure.

Impellers as of the radial blade type or radial Y blower are mounted upon a common shaft 40 mounted .in bearings ll which are in turn mounted upon the side walls 36. I use the term "radial blower type to denote theztype oi impeller which impels the air outwardly with respect to the impeller axis, rather than along the axis as with a fan-type impeller. A suitable number of bearings is provided to support the shaft adequately, and each bearing is so mountedas to allow freedom for shaft alinernent. As shown in Fig. l, 42 represents the external race ring of a.

ball bearing carrying the shaft 40. This external bearing ring is carried in an internally recessed rubber ring 43, into which the external ring of the bearing is forced. The rubber ring is also externally recessed, and isforced into the carrier ring 44 of mounting bracket a which is mounted on side wall 36 of the casing. a

Impe1iers'39 are preferab y d bl n form and 70 through car wall 2! at one side.

5 plane, and is mounted upon the shaft by clamping bolts 41 which secure the two halves together.

This structure makes for easy manufacture, as

each impeller half can be accurately die-cast: and it also makes for ease in the removal and re- 1 placement of any injured impeller without having to dismantle the whole assembled impeller unit.

The direction of air movement through the 1mpeller unit, as indicated in Fig. '7, is always the same regardless of the rotational direction of the impellers. Each partition 31 is provided with an are not occupied by the impellers, are open at the 'side of the casing opposite the side at which the impeller occupied spaces are open, as is clearly at the opposite side of the casing. The net result is that air travels through the whole impeller unit in the longitudinal direction indicated by the arrows in Fig. 3.

The whole impeller unit is placed transversely of the car, resting upon car floor 20. The lading racks are cut away to receive the impeller unit, and transversely extending screens 50 are secured to the ends of rack stringers 25 at opposite sides or the unit. These screens operate to screen out any solid material which might otherwise be carried by the air stream into the impellers and damage them.

Cover plates 5i and 5 is are secured to the floor racks. These cov r plates have depending side 4 flanges Bib which are secured to and across the several stringers 25 of the two hinged floor racks. the covers being thus mounted at such an elevation that they fit down closely over the upper.

edges of side walls 36 of the impeller casing. To

strengthen, the casing and to provide a better support for covers 5! and ila, longitudinal angle bars 52 are extended along and welded to the upper edges of sidewalls 36. Thus the cover plates are secured to and supported at their edges 0 by the floor racks, and in their normal positions are supported intermedlately by side walls 36 and angles 52; so that the cover plates are effective to carry any load that may b placed upon them. And for load carrying purposes the upper surfaces of the cover plates are flush with the upper surface of the ladlng floor.

i The cover plates interconnect the two sections of each lading rack at the points where the lading racks are cut away to accommodate the impeller unit; so that the two hinged lading racks may be raised each as a unit. To close the top of the impeller casing at the gap 54 between the adjacent ends of the two cover plates, a special local covering plate 55 is utilized. This-covering s5 plate 55 lies under cover plates 5| and its and has hooked flanges 55a which hook under the angle bars 52.

In the installation as here shown (as applied to existing cars) impeller shaft 40 extends pose an opening is cut through the car wall and lined with a tubular liner 51. The annular space between the shaft and liner 5! is sealed by some suitable means to prevent inflow of air at that 7 point. The suitable device indicated at 58 is For this pur- V composed of a series of discs-alternately attached to the shaft and to liner 51. The outer end of shaft 40, external of the car wall, carries pulley 60 adapted to take V-belt 6|. Pulley 60, as shown better in detail in Fig. 13, has an outer screw-threaded hub 62 adapted to take another pulley 53 for the independent motor drive which may be applied to shaft 40 when the car is not in motion, as will be hereinafter described.

In the form of driving mechanism shown in Figs. 1 to 6a, a transverse tubular mounting'shaft 65 is mounted directly under the car floor with its inner end rotatably carried in a bracket 66. conveniently mounted on one of the longitudinal girders $1 of the car body. The outer end of mounting shaft 65 is rotatably carried in a bracket plate 68 secured to the under side of the car body in a position substantially flush with the outer side of the car wall. Just inside the bracket plate 68 an armiS is mounted at its upper end loosely around mounting shaft 65, so

that although that end ofarm 59 is thus restricted to a swinging motion, it is to a certain extent allowed universal motion. Arm 69 extends diagonally downwardly and at its other end is attached, preferably rigidly, to the outer end of the tubular shaft housing 10. A brace 89a is placed between housing and arm 69. The purpose of this rigid, braced attachment is to enable arm 89, which is confined longitudinally in which handle 88 may be raised and lowered. Thenormalposition of handle 88 is its lower position as shown in the drawings, but it may be raised and held in its upper position, shown in dotted lines in Fig. 2, by a pin 89 which may be inserted in the plate 86. The handle W has a loop 80 at its inner end loosely surrounding the mounting shaft 5, or the extension thereof which is formed by the stud 65a. A collar 9! surrounds shaft 65 and carries a lug 82. The collar, tubular shaft 65 and shaft stud 65a are all secured together and lug 92 is positioned appropriately, bya pin bolt 93. A head 6% which lies outside the bracket plate 68, acting in conjunction with the fixed collar 9| and the parts 69 and 90, limits longitudinal (axial) movement of shaft 65 and of the mounting arm 6}.

In the normal operating positions of the parts lug 92 is in such position that handle 38 lies below it with a sufllcient clearance to allow the driving shaft I5 and traction wheel 19, and

' 'mounting shaft 65, the necessary amount of motion about the axis of shaft 85 for normal operaat shaft 65-see Fig. 5to confine the shaft housing I0 against movement longitudinal of itself. The inner end of shaft housing tube I0 has a pair of opposite perforated lugs 1i through one of which there extends the bent end 12 of an arm "i3 rigidly mounted at its other end on mounting shaft 65. In its normal or average operating position the shaft housing "1 is preferably substantially parallel to mounting shaft 65. The lug H which is shownas unused in Figs. 1 and 3 is provided for use when the mechanism is set up at the end of the car opposite to that which is here being described. I

Driving shaft 15 is carried in bearings IS in a shaft mounting member which is here shown in the form of a tubular housing 10, the bearings taking end thrust as well as radial. At its outer end this shaft carries drive pulley 11 which alines with pulley 60 and takes the V-belt 6|. At its inner end the extended end of shaft 15 carries the hub 18 of traction roller 19. This traction roller, whose structure and form will be hereinafter explained in detail, carries an external traction tire 80 of rubber or any other suitable material adapted to be frictionally driven by the periphery of car wheel 8|.

To keep traction roller I9 in pressure contact with the car wheel, and also to put the desired tion, without lug 92 coming. into contact with handle 88. Such relation of the parts is shown in Fig. 4. when handle 88 is raised it comes into contact with ing 92 and rotates mounting shaft 65 in a clockwise direction in Figs. 2, 3 and 4. Arm I3 is correspondingly swung upwardly, lifting the inner end of shaft housing 10 and lifting traction roller I8 off car wheel 8 l In this operation the outer ends of housing 10 and the driving shaft 15, and pulley 11, are not moved except to tilt them slightly about the universally loose and traction wheel 19 determining the proportionate applications of the pressure to those respective members. As shown in the drawings, a coil spring 82,coiled about mounting shaft 65, is conveniently used for the purpose, the free end 83 of the spring pressing downwardly upon housing 10 at the chosen position, which is here shown as being closer to roller 19 than to pulley 11. The fixed end 84 of the spring (see Figs. 2 and 4) bears upwardly in a notch 85 in the lower end of an angle plate 86 which is secured to the bracket plate 68.

This angle plate 86' also has a vertical slot 8'1- mounting of arm 69 on shaft 65. Those parts can of course be lifted if desired to loosen the belt and put it out of tractive engagement with the pulleys. The parts can be locked in this position by use of pin 89, and traction roller 19 ma then rotate freely to accommodate the independent power driving of the system, afterwards described.

The casing which encloses the belt drive and affords a mounting for the independent motor drive, is made up essentially of a removable cover plate and an upper end wall 96 and side walls 91 which are preferably formed of a single piece of metal of z-sect on cut and bent at the corners at 98. The rear flanges 99 of the Z-section' are secured to the outer face of the car wall and to the outer face of bracket plate 68. The cover plate 95 has inturned flanges I00 along its longitudinal edges adapted to engage the outer flanges I0! of the side walls. The lower end of the cover plate is bent inwardly and then upwardly as shown at I02 in Figs. 1 and 2 to form a protective casing below thedrive pulley l1; and bolts or pins I03 hold the cover in place. The cover may be easily removed by removing the bolts W3 and sliding the cover downwardly. Details of forma tion of the casing and its cover plate may be seen more readily in the horizontal sections of Figs. 12 and 14. Although Fig. 12 is illustrative of the modified form of driving mechanism, the casings for both forms of the mechanisms are the same and have therefore been given the same numerals in Fig. 12. The drawingsshow how the belt drive is arranged in a plane parallel and close to the car wall. and the enclosing casing is fiat and shallow, projecting only a small distance from an opening M5 to facilitate attachment of the independent drive pulley 63. This 'pulley, as

shown in Fig. 13, has aninternally threaded hub IOS adapted to be threaded onto the threaded hub 62 of pulley 68. The direction of threading pulley 63 onto hub 52 is the same as the direction of drive by the independent drive motor M. Motor M has a drive pulley I01 of suitable size, and belt )8 drivingly interconnects pulley I01 with pulley 63. Motor M is mounted at its pulley end on a bracket 09 which has inturned flanges H forming sliding guides for the bracket and motor on the longitudinal edges of cover plate 95. Set-screws II I maybe used instead of one of the flanges, so that by retracting the set screws the motor bracket may be removed from the casing cover without having toslide it vertically over the end of the cover.

Whenever it is desired to drive the impeller unit from the independent motor M, it and the pulley 63 and belt I08 are put in place as shown in Figs. 13 and 14. Handle 88 is raised to the dotted line position in Fig. 2, and locked in that position. Raising the handle 88 rotates arm 13 about mounting shaft 65 and thus raises the traction roller 19 off car wheel 8|. In this operation only that end of shaft housing 18 which is adjacent friction roller 19 (the left-hand end in Fig. l) is raised. The other end of shaft housing 10 is allowed to remain substantially in the position of Fig. l by reason of the looseness of arm 59 at its mounting on mounting shaft 65. Thus the drive belt 6| is not disturbed by raising traction pulley 19, but remains at all times in proper contact with the two drive pulleys 60 and 11.

It is preferred that the independent motor drive be applied directly to the upper impeller unit shaft, as has been described. But it may be applied to the lower driving shaft, such as, the shaft 10 that has been described, forthe driving belt 6| is always in traction relation toits two pulleys.

In certain aspects of my invention, for instance those relating to the independent driving of the impeller unit, the normal drive from the running gear may be had in any suitable manner. I prefer however to take that drive by friction traction from a wheel on the running gear, and certain aspects of the invention relate to driving mechanism for that purpose. In that connection the wheel illustrated at 8| in the drawings may represent any wheel on the running gear. Preferably however it is the car supporting wheel, and further features of the invention have to do with utilizing traction drive from that wheel.

In the form of driving mechanism which has so far been described, the whole mechanismds mounted upon the car body, and a certain amount of relative lateral movement takes place between car wheel 8| and traction roller 19 when the truck swivels with relation to the car body in rounding curves, or shifts laterally with respect to the body. Figs. 6 and 6a show how the lateral component of the relative movement between car wheel and body is accommodated.

Referring first to Fig. 6, the tread of the car wheel is shown at Bla and its flange at Mb. The rubber or other tire 80 of the traction roller is made with tapering side surfaces 19a and preferably with a fiat outermost peripheral surface 19b. The general sectional shape of the tire may be described as outwardly tapering, and preferably with a flat outermost periphery so as to provide a fairly broad traction surface for engagement with wheel tread 81a in normal operation. In normal operation, on straight-away track, the traction roller 19 occupies a relativ position somewhat like that shown in Fig. l and shown 'such a curve.

at position A in Fig. 6. Relative movement of the traction roller to the left (or the wheel 8| to the right) in Fig. 6 will cause its lefthand tapered surface 19a to climb wheel flange 8|b to the rqlative position shown at B, and further relative movement of the traction roller toward the left makes the traction roller reach the relative position shown at C where its righthand tapered wall 19a. is riding the inner surface of the wheel flange. In all these relative positions the traction roller is in frictional driving engagement'with either the car wheel tread or the flange. And on relative movement of the traction roller toward the right in Fig. 6, it may move relatively as far as the position shownv at D, where its lefthand tapered surface is still in frictional driving contact with the edge of the wheel tread. On return movement toward position A the lefthand tapered surface 19a will climb the outer edge of the wheel.

In the arrangement which is shown in Fig. 8, traction wheel 79 is prevented from dropping below the position D, in case it should passfurther relatively to the right, by the lug 82 (see Fig. 4) engaging should under any circumstances pass further relatively to the right than position D, it will always be held at such a level relative to wheel tread 8| (1 that upon reengaging the wheel tread it can climb back to position A. The friction roller may thus at times. go out of driving contact momentarily when the car is' rounding short curves, but it will immediately move back into proper driving contact as the car passes beyond The freedom which is allowed the traction wheel in a direction radial of the car wheel, allows the traction wheel to climb and descend the Whole tread and flange contour of the car wheel. I

In the arrangement shown in Fig. 6 the relative position C is substantially the limiting position of the traction roller toward the left. By choosing the normal relative position to be substantially that shown at A, it is found that ample relative latitude of movement is allowed without the roller'havi'ng to reach or pass beyond the position C in its relative movement toward the left. And, as before stated, it may pass beyond its relative righthand position D without any harm.

To allow the roller to pass beyond its relative righthand position shown at D in Fig, 6, without losing driving contact with the car wheel, the arrangement shown in Fig. 6a may be used. Here the tread body of the traction roller is the same as before described, but it has at 8 its lefthand end a cylindric extension 18d, composed of the same substance as the tread. The

diameter of this extension is such that its pe' riphery clears Wheel flange 8|b when the roller tread 79b is riding on the wheel tread 8|a. The length of cylindric extension 19d is such that when the roller reaches such a relative position as shown at D in Figs. 6 and 6a, the periphery of 19d will then ride on the wheel tread; but in lowering to the position D the end of extehsion 19d Will clear the wheel flange. With 19d riding the wheel tread the traction roller may then move further out relatively toward the right without losing tractive engagement. The eXtension 19d also performs the oflice-of limiting'the downward movement of the traction roller in its extreme righthand position, and the limiting in the posishown at D.

handle 88. Thus if the roller flame" WE h t on'rb eif Pf w .eeey'ene truck there is [sf mete nifiw tlve longitudinal iii ve n t, movementsioi the. A I ere "ween Y care of hithe action trection wheel in content with the.

position" thefira iiialflir cehltefs' orshait eeen "1 terigent 'to eticlrcle ooncehtri 1 1: t t i Swinglhe otion 50$ traction isheit this therefore subste nt wheh' wheeltijmo o of ermflt 'str'e -siich thetin rzspiihe presse' swm gm ,7 tion roller is epprox m' These descrihedd me eeeeeie i 5 Wither, such a, traction roller may eh opposite cylindric eigtenslon suchmeshown it We in Figft'a,whichzlwilliridjth periphery reletively'to the meme in the swivellinemovement between t e oneitu i ei fi emen/between the car :p y andiany me the-tl mgk f eptvra I and the swinging action of arm 1 tueiihelly, traction roller" 'ill e n'cl theiz'iiierencl f it she allowe ihythe" ot their joute d the h fil l trsveilihe 'exist y me em -"wherein l meritbetweeh carbodyanci truck is Qree. e Withtr cksemployingsyyi g hangers for leterel motion, -it"'is pre'ie'rredtduse the form of driving mechanism which is now to he described. Thie 60 modified form of driving mechanism is shown particularly in Figs. 3 to 12. The impeller unit, its drive by the pulley ml, and its drive by infiegcehdehtdrive motor M, are the some as before described.

in Fig. 8 the numeral 2%?) egeln deslghetes the car floor and; 8t the ear Wheel. Numeiel will designates e part of the truck frame. The impeller unit which is driven by the mechanism showii in Fig. 8 is the same as hefore described. the belt BE of Fig. 8 driving the impeller unit in the same manner. The casing enclosing the belt drive is made up in substantially the same manner as has been described is'mQlmted;onzhubfisleeve l3 2 eteblytofrubber orssorh'e good tree on m erial e-i cl has a; heoedwtlieafl a, -slightiy conicaluto cbhform t th breclrets 52% which are for co ve iez ce z noilihted in lithe? ,onerat iomo the":- deVl'ce,

whic I v ade 65 ings of the hectrihgs in these arms, are such as to restrict clrlve shaft Mi against endwlse dis- Dlecement.

A coil spring we eurroumis sleeve it! and has its fixed end it? passing througha lug use which is mounted on the mounting bracket H52 (see Fig. 9).

The free end 1% of the spring bears egelnst hearing housing MW in such a, direction as to tend to swing arm 6% and bearing housing and that end of shaft m downwardly and to tubular hearing member 1125 is mounted on w the i h n The adial length of a m .are raised away from the car wheel.

In this latter described form of driving mechanism the traction roller I32 always occupies substantially the same position with relation to the car wheel, as regards lateral movement. Being carried by the truck frame, thetraction roller. has substantially no lateral movement relative to the car wheel. Lateral motion of'the traction roller with relation to the car body is taken up by the sliding motion of drive shaft I32 through hub sleeve I30. And all other relative motions between the car body and truck are allowed by the universal freedom of shaft I3I to take, within the necessary limits, any relatively angled position that may be required. Traction roller I32, due to this type of mounting, keeps in tractional contact with the wheel tread regardless of the angle through which the truck and wheel may swivel with relation to the car body. This formof driving mechanism is therefore universally applicable, and is particularly applicable to long care where the angles of swivelling action are large, and to trucks incorporating swing hangers for lateral motion.

It has been mentioned that the drawings show the air impeller and driving mechanisms in their design and arrangement as they are preferably applied to existing cars. on most existing cars there is suflicient room between the external surface of the car wall and vthe so-called clearance line" to accommodate those parts of the driving mechanism that are here described as being located outside the outer surface of the car wall. And in applying the mechanisms to existing cars it is more convenient to place them external of the wall. However. the wall may be recessed to receive the upper parts or the drive mechanism; or the driving belt-may even be run up through the car floor interiorly of the normal car wall and housed by an interior housing which may be regarded as an inward recessing of the car wall to a depth greater than the normal wall thickness. Such arrangements may be more easily applied to cars that are designed particularly to take-my mechanisms, but they may also be applied to existing cars if desired or necessary. In any such arrangement the recessed wall may be regarded as the car wall for the purpose of my invention and the definition 01' certain of its aspects in the following claims. Other aspects 0! the invention, M11 as those having to do with the impeller unit in itself or the lower driving mechanisms, will be understood to be not necessarily impeller structure and its Claims directed to the subthe plane of its adapted to carry load.

2. In a refrigerator car having a car door and a lading floor spaced above the car flopr; an elongate air impeller unit extending lengthwise across the car in the space between the planes in the space the two floors, said unit including a casing having upper and lower walls, side walls and trans verse partitions which enclose'a series of spaces which are alternately open at opposite sides of the casing, the transverse 3 pported in the medium 01' distortable WILLIAM E. VAN DORN.

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