US2832436A - Stair elevator - Google Patents

Description

B. ROBERTS STAIR ELEVATOR April 29, 1958 8 Sheets-Sheet 1 Filed Aug. 26, 1953 INVENTOR Bruce Roberts WZfi fi ATTORNEY I mwN TR mmw o Q @N mmm 1 m mm MT MM QwQw Q Q FLrL B. ROBERTS A rfl 29, 1958 STAIR ELEVATOR' Filed Aug. 25, 1953 8 Sheets-Sheet 2 ll llllnll l' l 56 /?4 INVENTOR Bruce Roberts f3 ATTORNEY B. ROBERTS April 29, 1958 STAIR ELEVATOR 8 Sheets-Sheet 3 Filed Aug. 26, 1955 INVENTOR Bruce Roberts A ORNEY III/1 Aprii 29, 1958 B. ROBERTS 2,3

STAIR ELEVATOR Bruc Roberts Wgg ' ATTORNE April 29, 1958 B. ROBERT$ 2,

STAIR ELEVATOR Filed Aug. 26, 1953 8 Sheets-Sheet 5 INVENTOR Bruce Roberts JRNEY United States Patent 2,832,436 Patented Apr. 29, 1958 nice STAIR ELEVATOR Bruce Roberts, Oberlin,

Ohio, assignor to U. 5. Automatic Corporation,

This invention pertains to the art of hoists and, more particularly, although not exclusively, to a power hoist adapted to be installed on the stairways of homes and other structures for carrying people or goods either up or down.

In the past, such hoists have consisted of a rail or rails mounted parallel to the slope of the stairs and a powerdriven car which moves up and down the stairs in response to the operation of controls, the car being guided and supported in its movement by the rail or rails.

Originally, such hoists when applied to stairways used twospaced rails and the car generally had roller means so that it could move in a friction-free manner on these rails. Unless the stairway was unduly wide, the use of two rails generally interfered with the normal use of the stairway and made it either dangerous to use or entirely unuseable unless the hoist itself were employed. To overcome this difficulty, hoists were constructed wherein only one rail at one side of the stairway was employed. However, when using only one rail, the Weights on the car were supported on an overhung portion and the leverage of this weight required that the one rail be rugged in construction and thus unduly bulky and unsightly. The problem was sometimes overcome by the use of a rail member mounted on the wall alongside the stairway and spaced upwardly in the vicinity of where a hand rail would be positioned. Such constructions were not only expensive in construction but also unsightly and involved many difliculties of installation.

Because of the leverages involved and the ruggedness of the structures required, it has heretofore been required that the rail or rails be rigidly fastened to the stairway by means of bolts, screws or other means. Such means leave irremovable scars which are extremely unsightly if the hoist ever has to be removed.

Another problem with hoists of the type to which this invention pertains was that of controlling the operation of the car. In some devices, the drive motor has been mounted on the car along with the motor controls. However, such a construction always required some form of flexible electric power-transmitting means to the car so that the motor could be energized. Other constructions employed a motor separate from the car, the car being driven through suitable mechanical power means. Here, the problem became diflicult of controlling the mot-or from the car, it still being necessary to have some form of flexible electrical wiring connecting from the controls on the car to the motor. Mechanical members have been employed to connect the car with controls located adjacent the fixed motor, but such mechanical means were generally always highly complicated, and expensive to manufacture.

Another problem with these hoists has been the expense of manufacture. Generally, the hoist had to be custom built to the particular stairway on which it is to be installed. This requires special custom Work which is always expensive. Furthermore, hoists which could be installed on either the right or left-hand sides of the stairway had to be carried in stock. This made the problem of selling more difficult and further increased the price of the hoist to the ultimate consumer.

The present invention contemplates, in combination, a stairway elevator comprised of a rail adapted to extend the length of a stairway, means for mounting the rail, a car movable on the rail and power means connected to the car for moving the car on the rail which overcomes all of the above referred to difiiculties and provides a hoist which can be mounted on an existing stairway without marring the structure in any way, which can be readily adapted to accommodate any length or slope of starway, which is fully reversible so as to be readily mounted on either the right or left-hand side of the stairway, which has a simple, positively operated control system and which is so inexpensive to manufacture that it can be sold to people with limited means.

In accordance with the invention, the stairway elevator is fastened to the stairs as an integral unit in such a manner that no piercing or marring of the stairs or the adjacent structure need be done such as would be necessary with nails or screws. The rail extends the length of the stairway parallel to the slope thereof. Brackets are fastened to the rail and have clamp means for fastening to a portion of the stairs by a clamping action, this fastening normally being done to the projecting lip of the stair tread. By loosening these clamping means, the entire hoist may be removed from the stairway as a unit, leaving the stairway in the same physical condition as before the hoist was installed.

Independently of the above or in combination therei with, the car is so formed in conjunction with the steps that the rail can be of light construction and still resist the torques from the overhung weights. The rail is mounted close to either side of the steps: and, thus, the car has an overhung portion which carries the load. The car is provided with means spaced laterally; that is, in the plane of the steps, from the rail which engage in a progressive manner the lips of the steps as the car moves up and down the steps. Such means in engaging the lips of the steps support the vertical component of the overhung weight of the car. By overhung weight is meant that weight laterally spaced from the vertical plane through the rail. It will be appreciated that if the forces on the car are analyzed, there will be a vertical component of force which is generally the vertical plane through the rail. Such a force tends to twist the car in a plane perpendicular to the length of the rail which, in prior constructions, had to be resisted entirely by the strength of the rail or by other rails. However, with means which can treads as the car moves up and down, this overhung weight is readily supported Without any twisting stress of any kind on the rail. It will be appreciated that there is also a component of force in the plane of the stairway but such component of force is readily resisted 'by means of the spaced rollers of the carriage on therail and by providing the rail with in the plane of the stairway sufiicient to resist the torque forces caused by the component of force in the plane of the stairway. It will be appreciated that a fiat strip of metal would have such a moment of inertia. By so sup porting the overhung weight of the car, it will be seen that a rail of minimum size and bulk may be employed.

The means engaging the lips of the treads are so arranged as to have a low-frictional engagement therewith. This may be done by rollers, an endless belt, or by a skid member having a low friction surface for the steps. Ny-

have been found satisfactory.

spaced a considerable distance from engage the lips of the a cross-sectional moment of inertia assaese The power means drive the car on the rail through flexible tension members, a chain and sprocket drive being preferred, resilient means being provided to take up the shock of starting and stopping.

The control means also contemplates, either independently of or in combination with the above, of mechanism for controlling the automatic stopping of the car when it reaches the desired limits of travel which is an integrated part of the control means and independent of the car or its drive cable. Such mechanism includes a switch and member relatively movable in amounts and in a direction proportionate to the movement of the car, which member actuates the switch at either end of the travel to stop the power means and to condition it for appropriate rotation when next started.

The control means also includes an arrangement whereby the car may be quickly brought to a stop and positively retained in the stopped position which does not involve large energy dissipating braking surfaces or the like or self-locking gear trains. Thus, at the instant the downward movement of the car is to be stopped, the motor is energized for rotation in the opposite direction until it just commences to reverse. At this instant, a mechanical holding means is applied to lock the car against further movement. This last means may be an electrically operated brake member engaging the motor armature or any other moveable portion of the hoist.

Independently of or in combination with the above features, all parts which go to make the hoist are so constructed and arranged that they may be assembled on either the right or left-hand side of the stairway. Thus, the power means includes a motor which drives the car through a gear-reduction box, the motor having a larger radius than the desired spacing from the wall or side of the stairway of the output shaft or plane of the rail. This box, in effect, has two input drive gears spaced in a plane perpendicular to the length of the rail and disposed on opposite sides of the plane through the rail. Depending upon the side of the stairway in which the hoist is to be mounted, the appropriate drive gear is selected by properly mounting the electric drive motor. With such an arrangement, it will be seen that even though the radius of the drive motor is greater than the distance between the plane of the rail and the wall adjacent to which it is to be mounted, the entire assembly can be mounted in extremely close proximity to the wall by simply selecting the appropriate input drive gear for the gear-reduction box.

The principal object of the invention is the provision of a new and improved hoist of the type adapted to be installed in or on stairways of existing structures which is simpler in construction, less inexpensive to manufacture, more easily installed and removed and less bulky than prior known devices.

Another object of the invention is the provision of new and improved means for fastening a hoist of the character described to stairs of existing structures which is simple in construction and does not necessitate the use of any fastening means which would in any way mar the surfaces of the stairs or its surrounding structure.

Another object of the invention is the provision of a new and improved hoist of the character described which enables the use of a rail having a minimum bulk and minimum weight of material therein. Still another object of the invention is the provision of control means for electric hoists which requires no electrical connection between the moving car and the electric power means and, yet, which is simple, safe and effective in operation.

Another object of the invention is the provision of a new and improved control means for electric hoists which provides for power braking of the motor by energizing the same for rotation in the opposite direction until it has reached a dead stop and then the application of a mechanical brake to prevent further rotation thereafter.

Still another object of the invention is the provision of a new and improved hoist of the type which is adapted to 4. be installed in the stairways of existing homes and other structures which is completly reversible so as to be readily installed in either the right or left-hand side of a stairway.

Still another object of the invention is the provision of new and improved control means for electric hoists of the type described wherein a single mechanical member movable in two directions controls the starting and stopping of the hoist.

Still another object of the invention is the provision of a new and improved hoist of the type described which can be installed in an existing building in an absolute minimum of time, thus reducing the over-all cost to the ultimate consumer.

The invention may be comprised in certain parts and arrangements of parts, a preferred embodiment of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof, and wherein:

Figure l is a perspective view of a conventional stairway showing a hoist illustrating a preferred embodiment of the invention mounted on the right-hand side of the stairs, the same hoist without the car being shown in dotted lines mounted on the left-hand side of the stairs to indicate the reversibility of the hoist to be described;

Figure 2 is a top elevational view of the upper portion of the stairway of Figure 1 and showing the car at the upper limit of its movement;

Figure 3 is a view partly in section and on a much larger scale of the power means and controls therefor;

Figure 4 is a fragmentary, cross-sectional view of Figure 3 taken approximately on the line 44 thereof and showing the mechanical braking arrangement for the power means;

Figure 5 is a front elevational view of the power means of Figure 3 with the cover removed and showing in greater detail the control means for the power means;

Figure 6 is a detail view of the operating arm for the control means;

Figure 7 is a fragmentary, cross-sectional view of Figure 5 taken approximately on the line 77 thereof;

Figure 8 is a fragmentary, elevational view of Figure 5 viewed from line S8 thereof and showing the actuating means for the control arms of Figure 6;

Figure 9 is an end view of Figure 5 taken approximately on the line 99 thereof and showing details of the plugging switch for the power means;

Figure 10 is a cross-sectional view of Figure 9 taken approximately on the line 1tl10 thereof and showing details of the mounting of the arm of the plugging switch;

Figure 11 is a view of Figure 3 taken approximately on the line 1111 showing details of the power means and how the power means are adaptable or either right or lefthanded installation and including the lower end of the rail means with the control for actuating the power means;

Figure 12 is a cross-sectional view of Figure 11 taken approximately on the line 12-12 thereof;

Figure 13 is a cross-sectional view of Figure 11 taken approximately on the line 13l3 and showing details of the mounting of the control rod;

Figure 14 is a fragmentary view of Figure 11 showing the rail mounted on the power means for a left-hand installation of the hoist;

Figure 15 is a top elevational view of a rail employed in conjunction with the present invention and showing how two lengths are joined together to form the completed rail device;

Figure 16 is a bottom plan view of the carriage which engages the rail and moves thereon;

Figure 17 is a side elevational view of Figure 16 on a somewhat smaller scale and showing the adjustable feature for enabling the supporting surface of the car to be adjusted to correspond tothe slope of any stairway;

Figure 18 is a view partly in cross section showing a side view of the car to be mounted on the carriage of Figure 17 and including the means for supporting the outboard unhung portion of the car;

Figure 19 is a view showing the carriage, together with the means for transmitting the power from the power means to the car;

Figures 20 and 21 show detail views of mechanism for automatically locking or braking the car in the event the drive of Figure 19 should fail for any reason;

Figure 22 is an end view of the car shown in Figure 18 partly in section showing the control means on the car and also showing in detail the method of mounting the rail on the lip of a stair tread;

Figure 23 is a perspective view of a bracket for sup porting the rail on the stairway;

Figure 24 is a side elevational view of the means for supporting the outboard unhung portion of the car, together with the antifriction means mounted on the lips of the treads;

Figure 25 is a cross-sectional view of Figure 24 taken approximately on the line 2525;

Figure 26 is a side elevational view of a modified embodiment of the means for supporting the outboard end of the car;

Figure 26a is an end view of Figure 26, taken approximately on the line 26a-26a thereof;

Figure 27 is a cross-sectional view of Figure 22 taken approximately on the line 27-27 thereof;

Figure 28 is an exploded view of the control levers on the car which, when actuated, start or stop the movement of the car;

Figure 29 is a view somewhat enlarged showing how the movement of the control arms actuates a member for transmitting the control movements to the control box on the power means;

Figure 30 is a fragmentary, cross-sectional view showing the operation of the automatic stop on the car in the event it should hit an obstruction in the course of its movement;

Figure 31 is a circuit diagram of the control circuit for the power means;

Figure 32 is a top elevational view of a modified embodiment of the invention;

Figure 33 is a side elevational view thereof;

Figure 34 is a cross-sectional view of Figure 33 taken approximately on the line 34-34 thereof; and

Figure 35 is a schematic wiring diagram of a modified embodiment of the control arrangement.

Referring now to the drawings wherein the showings are for the purposes of illustration only and not for the purpose of limiting the invention, Figures 1 and 2 show a stairway indicated generally at A with a hoist embodying the present invention installed thereon, the hoist being comprised generally of a rail B, a car C and power means D for driving the car up and down the stairway A.

The stairway A forms no part of the present invention,

' except insofar as certain elements thereof may enter into combination with certain parts of the hoist and is shown to indicate a typical stairway such as might be found in any existing home or structure on which the hoist of the present invention may be installed. The stairway includes a top step which may be a landing inbetween a pair of stairways, a step along the stairway or the upper floor to which the stairway leads, a bottom step 11 and a plurality of intermediate steps 12, each including a riser member 13 and a tread 14, each tread extending beyond the riser to form a lip as is conventional in stairways. The steps, as will appear, may have any desired slope and there may be any number of steps, the only limitation being that for the flight of steps which the hoist will cover, the slope being generally constant and that the height and depth of each step be generally uniform over the entire length thereof. Exact uniformity is not required because the present invention contemplates a certain degree of adjustability between the hoist and the stairway.

The stairway may be open on both sides or may be between two vertically extending walls 16 such as is shown in Figure 2.

The rail B may be mounted on either the right or lefthand side of the stairway but is shown in the figurestas being mounted on the right-hand side of the stairway and may be mounted flush with the right-hand wall 16 substantially as shown. The rail B is generally U shaped in cross section (see Figure 13) with the legs of the U lying in or parallel to the plane of the stairway. Thus, the rail B includes a lower leg or base 18, an upper leg or top 19 and a base or side 20 which interconnects the base 18 and top 19 on the side remote from the wall 16. As shown, the base 18 is somewhat longer than the top 19 for purposes which will hereinafter appear. The rail B may be formed of any desired construction but because of the present invention, may be made of relatively lightweight construction such as being manufactured from a fiat strip of steel rolled to the shape shown.

The rail B extends from a point either resting on or slightly spaced from the lower step 11 to a point above the upper step 10 in a straight line and at an angle corresponding to the average slope of the stairway A. The

a horizontally extending base 23 (see Figures 1 and 23), a

and an angular portion 24 which extends parallel to and is fastened to the underside of the rail B.

The bracket 22 is mounted in position with the angle portion fastened rigidly to the underside of the rail B by means of a bolt 27 and the base 23 rests on the upper surface of the tread 14 and extends back toward the riser 13 a substantial distance so that the weight of the hoist transferred to the stairway through the brackets 22 will be transferred at a point substantially removed from the lip 15. The right-hand end of the base 23 terminates in a. downwardly extending portion 28 of a length greater than the thickness of the maximum thickness of stair tread which will be encountered and which, itself, then terminates in a reversely bent portion 29 having a bolt or the like 30 threadably mounted therein and engageable with the underside of the lip 15. The bracket 22 is thus provided with clamping means engageable with the lip 15 of the stair tread whereby the bracket may be rigidly fastened to the stairway without in any way marring or piercing the surface thereof. Preferably, a layer of semiresilient material 32 is positioned between the base 23 and the upper surface of the stair tread 14. This material 32 preferably has a high coeificient of friction, both with varnished surfaces such as is normally found in stair treads and with steel from which the bracket is preferably made such that when the bolt 30 is tightened up, a very substantial frictional action will be developed between the bracket 22 and the stair tread 14 to prevent any horizontal movement of the bracket relative to the stair tread under any forces which may be imposed on the bracket. Any desired means for providing this frictional action may be employed including serrations on the underside of the base 23,- although such serrations might possibly mar the surface of the stair tread 14.

The angle of the portion 24 relative to the base 23 is made adjustable so that its angle may be made to conform to the angle of the rail B. This angular adjustment may be provided for in a number of diiferent ways but, in the embodiment of the invention shown, the angle portion is integrally joined with the base portion 23 by an upstanding portion 25 such that by bending the upstanding portion 25 relative to the base 23 and the angle portion 24, its over-all vertical height may be adjusted and, thus, the angle of the angle portion 24 may be adjusted. It will be noted that the free end of the portion 24; that is, the right-hand end as viewed in Figure 23', rests on the right-hand end of the base 23, a rigid construction thus resulting. The bending of the bracket 22 may be done at the time of installation or this bending may be done to a predetermined angle at the factory at the time of manufacture. it is preferred, however, that this bracket will be bent onthe job site at the time of installation. Thus, one set of brackets will accommodate any slope of stairway.

In addition to providing for this angular adjustment, the bracket 22 is also preferably made infinitely adjustable relative to the length of the rail B. Thus, the rail is provided with a plurality of. generally equally spaced openings 33 along its base into which the screw or bolt 27 extends. The angle portion 24, in turn, has an elongated slot 34 through which this bolt 27 also extends, it being appreciated that with the definite fastening positions along the underside of the rail and the indefinite fastening position provided by the slots 34 with the length ofthe slot 34 being greater than the distance between adjacent openings 33, an unlimited and completely free adjustment of the bracket 22 may be secured relative to the rail B. In addition, it will be noted from Figure 22 that variations in the outer edge of the lips 15 from the slope of the stairway may be compensated for by spacing the vertical portion 23 of the bracket 22 from the outermost end of the lip 15. Once the brackets are properly adjusted and the bolts 30 tightened up, a rigid and extremely strong and vibration-proof mounting of the rail B results.

The power means D is fastened or mounted securely on the rail B in such a manner that it does not have to be clamped or otherwise fastened to the stairway A and, yet, the rail B is not required to support the weight of the power means. Thus, in the embodiment shown (see Figure 3), the power means D include an electric motor indicated generally at 35 securely mounted on the upper side of the housing 36 of a gear-reduction unit 37. The housing 36 has an angled surface 36 which is bolted fast to the upper end of the rail B by means of threaded bolts 40 extending through openings 168', M99 in the lower side 18 of the rail into threaded openings in the housing 36. The angle of the surface 38 may be made to correspond to the average angle which it is anticipated will be encountered in normal stairways. Thus, if the angle of the stairway varies from this normal, the entire power means will be tilted to that amount but this has not proven detrimental. The housing 36 is provided with a plurality of legs which extend beyond the lower side of the housing 36 to rest on the upper surface of the upper tread 16'. One of such legs is in the form of a threaded bolt 42, threaded in the lower side of the housing 36. Another leg is in the form of a rod 43 bolted to the housing 36 at a point spaced from the bolt 42 and having a threaded bolt 44 extending from the lower end thereof, which bolt has a rubber foot 44' to engage the upper tread 10. With this arrangement, it will be appreciated that once the rail B has been mounted in position on the stairway A by means of the mounting means above described, the weight of the power means on the upper end of the rail B may then be taken up by properly adjusting the bolts 42 and 44 so that all of the weight of the power means D is resting on the upper surface of the tread ltl and none of the weight is being carried by the rail ll. With such an arrangement, the power means D are fully supported without in any way marring the surfaces of the stairway and, yet, the rail B may be of a light-weight construction, inasmuch as it does not have to carry the weight of the power means D. By virtue of the fact that the housing 36 is securely bolted to the rail B, any torques resulting from operation of the power means will be transmitted directly to the rail B. Such torques will not tend to impose forces tending to move the power means D relative to the stairway tread 10.

The electric motor 35 has an output shaft 45a arranged generally on a vertical axis extending downwardly into the inside of the gear housing 36 where a helical gear worm 45 mounted thereon engages a second helical gear 46 keyed to and mounted for rotation on a shaft 47 journaled in the housing 36 on an axis perpendicular to the axis of the motor rotor. A worm 48 (see Figure 11) is also keyed to the shaft 47 and engages a second work gear 49 keyed to a shaft 50 mounted for rotation about an axis perpendicular to the axis of the surface 38. This shaft 50 extends upwardly beyond the surface 38 and has a sprocket wheel 53 keyed thereon and held in place by a nut 54. It will be noted from Figure 3 that this sprocket wheel 53 is in a plane generally midway between the base and top of the rail B and drives a chain 56 to actuate the car C for movement in either direction as will presently appear.

It will be noted that there are two substantially identical helical gears mounted on the shaft 47, one being designated with the numeral 46 and the other with the numeral 46', which are disposed on opposite ends of the shaft 47 and, in particular, on both sides of the worm 48. In a like manner, the housing 36 has an opening 57 and 57 in the upper surface thereof through either of which the drive shaft of the motor 35 may extend to engage either worm wheel 46 or 46 respectively. The purpose of this construction will now be described. One of the objects of the invention was that the hoist could be mounted at will on either the right or left-hand side of a stairway. It is desirable that it be mounted as close to the wall on either side as is possible. A motor capable of driving the car C with such loads as might be imposed thereon has a radius greater than the desired spacing of the center line of the shaft 50 from the wall 16. If the drive shaft 45a of the motor were to be on the plane through this center line, it will be appreciated that one side of the motor would project substantially beyond the wall side of the rail B and would thus determine this center-line spacing. In accordance with the invention, the gears 46, 46 are spaced from the remote wall of the housing 36 a distance at least equal to one-half the diameter of the motor 35. Thus, as is shown in Figure 11, the right-hand side of the motor 35' may be tangent with the right-hand side of the housing 36 which, in turn, may be mounted substantially flush with the wall 16. However, if the hoist were to be mounted on the left-hand side of the stairway, the motor would be so mounted on the housing 36 that its shaft would enter the hole 57' and engage the gear 46. Thus, the left-hand side of the motor 35, the outline of which is shown in dashed lines indicated by the numeral 35', would be tangent with the left-hand side of the gear casing 38. It will thus appear that one gear casing will suffice for either right or left-hand mountings of the hoist with only the addition of a single gear in the gear-reduction unit and one additional opening 57' through the housing.

When the hoist is mounted on the right-hand side of the stairway, the motor 35 will be bolted to the housing 36 by means of bolts 60 extending through an opening 61 in the housing. For left-hand mountings, the bolts 60 will extend through the bolt hole 61'.

The particular construction of the gear-reduction unit, outside of the use of the dual input drive gears and the other features for providing either right or left-hand mounting of the hoist together with the angular output shaft and angle surface 38, form no part of the present invention and the unit will not be described further. It wil be appreciated, however, that because of the manner of mounting the power means against movement relative to the stairway and the method of supporting its weight, the entire motor means can be tilted at slight angles relative to the plane of the upper stair tread 19 so that full accommodations for different slopes of stairways can be had.

The car C is comprised essentially of a carriage indicated generally at 65 in Figures 16 and 17 and a'platfo'rrii indicated generally at 66 in Figure 18, which platform 66 is generally removable from the carriage 65.

The carriage 65 is comprised generally of a flat steel plate 70 having an upwardly extending flange 71 intermediate its ends, the platform 66 being mounted on this flange 71 as will be later described. The base 70 has two sets of three rollers mounted one at each end thereof which engage surfaces of the rail B and movably support the carriage 65 for movement along this rail. Thus, in the embodiment of the invention shown (see Figure 16), the lower side of the base 70 is provided with spaced rollers 73, 74 rotatable about a vertical axis; i. e., an axis perpendicular to the length of the rail B and spaced apart so that their opposed surfaces can engage respectively the flange 16 of the top leg 19 of the rail B while the other roller '74 engages the vertical side 20 of the rail B. The third roller 76 is mounted for rotation about an axis parallel to and spaced from the lower side of the base 70 on a downwardly depending flange 77 on the left-hand side of the base 70 as viewed in Figure 16. This roller 76 has a diameter just slightlyless than the spacing between the base 18 and top 19 of the rail B and extends between these two members. Thus, the rollers 73, 74 guide the carriage 65 along the length of the rail B while the roller 76 transfers vertical forces to the rail B.

There are three similarly disposed rollers 73, 74 and 76' at the opposite end of the base 70 which engage like portions of the rail B.

It will be noted that the carriage 65 as so far described may be used interchangeably on either a right or lefthand installation by simply turning the carriage 65, end for end, depending upon the side of the stairway in which it is to be employed.

The carriage 65 is moved along the rail B by driving means including a spring or cushioning mechanism to absorb the jolts of starting or stopping the power means and other means which provide a selflocking action in the event that the driving means should for any reason break. Thus, in the embodiment of the invention shown, the chain 56 which as heretofore pointed. out is driven by the sprocket wheel 53 is fastened at one end to a rod 80, the other end of which rod is half round over a considerable portion of its length and terminates in an offset portion 81. This offset portion bears against a washer 82 which, in turn, bears against one end of a long helical spring 83 coaxially around the half round portion of the rod 80. It will he noted that the rod 80 also has an offset 85' to clear the roller 76. Also extending coaxially through the spring 83 is a second half round rod 86 having an offset 87 at its upper end bearing against a washer 88, in turn bearing against the opposite end of the spring 83 from the washer 82. This half round rod 86 extends coaxiall through the length of the spring 83 and out of the opposite end to where it fastens to a pivoted eccentric 90 through a linkage 91, which eccentric is biased in a counterclockwise direction by a U-shaped spring 92 having one end engaged with the eccentric 90 and the other end engaged in a portion fixed relative to the carriage 70. The eccentric 90 is so located on the base '70 as to be disposed between the base and top 18 and 18 respectively of the rail B. The eccentric 90 is so dimensioned that when rotated in a counterclockwise direction, it will jam against the upper side of the base 18, thus locking the carriage 65 against downward movement on the rail B. The eccentric is so arranged that when tension is applied thereto through the chain mechanism 91, the coil spring 83 and the rod 80, the sides of the eccentric will clear the inner walls of the rail B. Thus, if for any reason tension. on the chain 56 should fail, such as would be caused by breaking of the chain 56, the eccentric 90 will be immediately rotated to the locking position shown in Figure 21.

The eccentric 90 is mounted for rotation on a shaft 93 mounted on the flange 77' by means of athreaded stud 94 threadably engaged in a threaded opening 95' in the flange 77'. It will be noted that the flange 77 has a corresponding opening 95 so that when the carriage is reversed for left-hand mounting of the hoist, the shaft 93 can then be mounted in the hole 95. Thus, the entire mechanism is simply reversed.

Also mounted on the shaft 93 is an arm 96 extending toward the lower end of the base 70, which member has a hook 97 extending laterally therefrom over which an end loop 98 on a flexible cable 99 is hooked. This flexible cable 99 extends interiorly of the rail B toward the lower end thereof where it reverses itself about a sheave 100 where it extends a substantial amount in the opposite direction and connects to one end of a helical spring 102, in turn connected at its opposite end to the end of the chain 56 opposite from the rod 80. This arrangement is more clearly shown in Figure 19. The purpose of the spring 102 is to take up any slack in the loop formed by the cable 99 and chain 56. When it is desired to have the carriage65 move up the stairway, it is pulled up. When it is desired to have the carriage 65 move downwardly, it does so under the force of gravity in a controlled manner with the chain 56 acting through the sprocket wheel 53 back to the motor 35 controlling the descent.

It will be noted that the sheave 100 is rotatably supported on a shaft 104 in the form of a bolt extending through aligned openings in the upperand lower sides of the rail 19 and 18 respectively at the lower end of the rail. (See Figure 12.) In Figure 12, it will be noted that there are two sets of openings in the upper side 19, 106 and 107, and two sets of smaller openings, 108 and 109, in the base 18. Reference to Figure 3 will show that the upper end of the rail B has similarly spaced and sized openings 106', 107', 108' and 109', the bolts 40 for fastening the rail B to the housing 36 extending through the openings 108' and 109'. The openings 106' and 107 provide access for a screwdriver or a wrench to the driving heads of the bolts 40.

It will be appreciated that if the hoist is to be installed on the left-hand side of the stairway (see Figure 14), then the openings 106, 107, 108 and 109 will be at the upper end of the rail and provide the openings for receiving the mounting bolts 40, while the openings 106', 107', 108' and 109 will be at the lower end of the rail with the openings 106' and 108 providing the mounting openings for the shaft 104.

The platform 66 is both removably supported upon the carriage 65 as well as adjustable angularly relative thereto. In addition, the platform 66 is so constructed and arranged that it can be used in either a right or lefthand installation of the hoist.

The platform is comprised generally of a step disposed in a horizontal plane and a front 116 formed of sheet metal and intersecting at a corner 117. The platform is also comprised of two end plates 120 and 121 rigidly secured to the step 115 and the front 116. The side 120 has a pair of aligned openings 123 adjacent the lower edge thereof. A key member 124 pivoted on a shaft 125 on a line between the openings 123 has a downwardly opening slot 126 and an upwardly opening slot 127 of a width somewhat less than the diameter of the openings 123 and so spaced that when the key member 124 is rotated, the slots 126, 127 will align with the openings 123.

The upstanding flange 71 has a plate member 129 mounted thereon having a pair of headed studs 130 extending to the right therefrom (see Figure 17) and spaced to correspond with the spacing of the openings 123. These studs 130 extend through the openings 123 and the key member 124 is then rotated so that the slots 126 will engage under the heads of these studs to mount the platform 66 relative to the carriage 65. As shown, the;

key 124 has a pair of ears 132, one at each end thereof,

which may be engaged by a suitable tool for the purpose of rotating the key member 124 to either engage or disengage the heads of the studs 130.

The plate member 129, in turn, is adjustably supported on the upstanding flange 71 by means of a pair of threaded studs 134 fastened to flange 71 and extending through vertical slots 135 formed in the flange 71.

It will thus be seen that the platform 66 can be readily mounted and dismounted relative to the carriage 65 and the angle of the plane of the surface of the step 115 can be readily adjusted relative to the plane of the base 70 and thus the plane of the rail B.

In accordance with the present invention, means are provided for supporting the outboard side of the platform in the form of a member which progressively engages the uppermost corner of the lip 15 of the stair treads 14 as the platform is advanced up and down the stairways. This engagement of the lips supports this component of the weight and prevents the twisting action on the rail 13. While various means can be provided, a preferred embodiment contemplates a skid member in the form of an elongated plate 140 adjustably fastened to the lower edge of the outboard side 121 by means of bolts 141 extending through slots 14?. in the plate 140. This plate has an elongated shoe member 144 fastened to its lower edge over which a sheet or sole of antifriction material 145 U-shaped in cross section as shown in Figure 25 is secured. Preferably, the shoe 144 is of resilient construction such as sponge rubber or the like. The sole 145 for the shoe 144 is preferably formed of nylon or Teflon. Further, in accordance with the invention, small pads 146 which will have a low coetficient of friction when taken in conjunction with the material forming the sole 145 are mounted over the lips of the treads and fastened in place by small brads 147. The pads 146 may also be of nylon or T efion. These pads also prevent wear on the upper corner of the stair lip 15. It is to be noted that in this one instant, the pads 1.46 are fastened to the stairs by means of nails or the like which will pierce and mar the structure of the stairway. However, such nails or brads are no bigger than would be employed in fastening car peting to the stairway and, in the event, that the hoist had to be removed from the stairway, these pads 146 could be allowed to remain without in any way interfering with the future use of the stairway.

The length of the shoe 144 must be at least the distance between two adjacent lips of the stairway and, preferably, each end of the shoe is turned upwardly at an angle as indicated at 148 which preferably gradually blends into the plane of the sole M in a gradual curve as indicated at 149. Thus any irregularities from tread to tread will not cause any difficulty. it will also be appreciated that if there is any substantial variation between the over-all slope of the stairway and any one tread, the variation can either be compensated for by cutting away the lip in the event it projects beyond the plane or building up any lip by the use of pads of greater thickness in the event the lip does not extend out to the plane of the overall slope.

Figures 26 and 26a show an alternative embodiment of a skid member useable with the present invention. Here, the plate 14!) corresponds to the plate 146 of the pre ferred embodiment. Mounted at each end of this plate are a pair of roller members 152, 153 and an endless belt 1.54 is rotatably supported on these rollers. Disposed intermediate the rollers 152 and 153 are a plurality of smaller rollers 156 having lower surfaces all arranged in a plane below the lower edge of the plate 140' and the belt 154 passes over these rollers 156 and any weight or upward forces placed on the belt 154 are transferred to the plate 140 through these rollers 156.

These rollers 152, 153 and 156 are all journaled at one end for rotation along the lower edge of the plate 140'.

These rollers are also journaled for rotation on the other end by a bracket member 158 fastened at its upper end to the plate and extending horizontally over the rollers and thence downwardly over the sides so that the axles of the rollers may extend thereinto. This construction is clearly shown in Figure 26a. it will be appreciated that with this embodiment of the invention, as the car is advanced up and down the stairway, the belt 154 engages the lips of the stair tread and remains stationary relative thereto while moving relative to the rollers 156.

It will be appreciated that the pads 146 can be glued to the stair treads if it is desired not to use the brads 147 or, in the alternative, clamps can be employed similar to that used with the brackets 22 for the purpose of fastening the pads 146 to the stair treads.

The principal part of this feature of the invention is that the outboard side of the car he provided with means of a length longer than the distance between two treads which move along with the car to progressively and consecutively contact the various treads for the purpose of supporting the outboard weight placed on the car.

By virtue of this feature of the invention, the twisting or torque action on the rail B in a plane perpendicular to its length is reduced to practically zero. Thus, the rail may have a much smaller cross-sectional area and Width than has ever heretofore been possible in what may be called a one-rail stairway hoist.

The motor 35 may be of any known type so long as it may be readily reversed in its direction of rotation. A repulsion, induction-type motor is described in this specification.

The invention also contemplates mechanical means actuated when the motor is not energized to prevent any weight on the car from turning the motor rotor and, thus, unintentionally, moving it down the stairway under the force of gravity. Such means, in accordance with the invention, are employed in combination with dynamic braking of the electric motor or, more preferably, plugging of the motor; that is, energizing it for reversed rotation until it has reached a dead stop. Thus, the mechanical locking means need only be of a size to effect a holding operation and not a braking operation as normally considered, that is, an energy dissipation operation, whereby the inertia of the moving parts of the hoist must be overcome by friction.

In the embodiment of the invention shown, the upper end of the motor-drive shaft is provided with a frictionbraking arrangement including a brake drum 160 keyed to the motor-drive shaft and engaged on its outer periphery by an arcuately curved brake shoe 161 having a frictional lining 162 thereon. This brake shoe 161 is mounted for movement toward and away from the brake drum 160 on the armature 163 of a solenoid-type magnet 164. The brake shoe is biased continuously toward the brake drum 160 by a helical coil spring 166, hearing at one end against the motor housing and at the other end against the back side of the brake shoe 161. Thus, when the solenoid 164 is not energized, the brake shoe is in engagement with the brake drum 160. Energization of the solenoid magnet 164 draws the brake shoe back from the brake drum 160. The solenoid is energized whenever the motor is energized for rotation and becomes deenergized at the moment that the motor itself is deenergized. As will appear, this deenergization of the motor only occurs at the instant when the motor is at zero speed and, thus, when the brake shoe 161 engages the brake drum 160, there is no relative movement between the two members.

Electric switches and operating mechanism therefor are provided for controlling the energization of the motor 35 to make it rotate in the appropriate direction and for controlling the energization of the solenoid 164. Such switches and operating mechanism are, in the preferred embodiment, shown as mounted as a subassembly unit 166 in the power means D. This subassembly unit 166 includes a generally vertically extending sheet steel base 168 having a pair of legs 169 angularly bent and fastened to the angular surface 38 of the gear housing 36 by means of bolts 170 threaded into the housing 36. It will be noted that the plane of this base 168 is generally tangent with the side of the motor housing toward the rail B and is also generally aligned with the output shaft 50 of the gear-reduction unit 37. p

This subassembly unit 166 in the preferred embodiment of the invention includes three switches preferably of the microswitch type; namely, a start switch 172 having an operating arm 172, a stop switch 173 having an operating arm 173 and a motor-direction control switch 174 having an operating arm 174. The last-mentioned switch is of a the single-pole, double-throw, snap-action type. When this switch is in one position, the motor is connected for energization in one direction and when in the other position, the motor is connected for rotation in the opposite direction. This switch is actuated to either one position or the other as the car approaches its respective limits of travel, the arrangement being such that the operating mechanism can be included as a component part of the power means D and there is, thus, no direct connection between this mechanism and the car other than the car-driving mechanism heretofore described, including the chain 56.

Thus, in the preferred embodiment of the invention, a threaded shaft 176 is mounted for rotation in upper and lower bearing members 177 and 178 respectively mounted on a bracket 1,79 fixed to the base 168. The axis of rotation of this shaft 176 is on a plane through the axis of rotation of the drive shaft 50 of the gear-drive unit 37 and a flexible drive cable 180 extends from the lower end of the threaded shaft 166, to the end of the drive shaft 50 with driving connections at each end. Thus, as the shaft 50 rotates to drive the car along the rail B, the shaft 176 will also rotate. Afollower nut 182 is threadably engaged with the shaft 176 andis prevented from rotation there with by means of a flat surface which slidingly engages the bracket 179. Thus, as the shaft 176 rotates, the nut 182 is advanced up and down the shaft and the movement of the nut is directly proportional to the movement of the car along the rail B. e

A follower member indicated generally at 184 is so shaped and mounted as to be engaged by the follower nut 182 at both ends of its travel so as to actuate the switch 174 to one position or the other. This follower member 184 includes a generally elongated vertically extending base 185 having a pair of elongated vertically extending slots 186 therein through which screws 187 extend into. threaded engagement with the bracket 179 so that the follower 184 is vertically movable in both directions at least to a limited degree. The upper end ofthe base 185 terminates in a horizontally extending portion 189 having an elongated vertically extending screw 190 adjustably supported thereby. In lower end of the base 185 terminates in a horizontally extending portion 192, in a like manner adjustably supa like manner, the,

porting a vertically extending screw 193. The screws t 190 and 193 are generallyin vertical alignment and so disposed as to be engaged by the follower nut 182 as it travels along the threaded shaft 176. The follower 184 also includes a portion adapted to engagethe actuating arm 174' with the switch 174. This portion, in the embodiment shown, is a downwardly extending extension 194 of the horizontal portion192, which portion 194 then terminates in an angular portion 195.

Spring members 196 are mounted under the heads of the screws187 to bias the follower 184 against the bracket 179. Thus, the follower 184 will remain in any adjusted position within the limits of its movement.

In operation, the follower nut 182 advances along the threadedshaft 176 to engage either the screw 190 or 193. If it be assumed that the nut is advancing in a downwardly direction, the follower will first be disposed in its uppermost position; namely, that shown in Figure 5. When the follower nut 182 contacts the screw 193, the

followemlSAis pushetltdownwardly until. the portion-195 has engaged the 1am; 174""to actuate the iswit'ch174.

and no further movement of the nut will occur.

When thenut 182 advances to the uppermost end of the shaft 176, it engages the screw to return the When thishappens, asiwill appear, the motor 35 isstopp'ed follower 184, to the position shown and allow the switch 172' and 173'. are inapproximately the same vertical planebut laterally spaced. A lever 200 is pivoted at its left-hand end (seeFigure 6 positioned below and to the left-hand line of the switches 172 and 173 in the plane of thebase 168 and has a pair of upwardly extending switch-actuating arms 202, 203, the former engaging the arm 172' and the latter engaging the arm 173'. This lever then terminates in a downwardly and outwardly extending portion 205 provided with an outwardly opening slot 206 into which an operating arm 207 extends. This operating arm 207 will be presently described.

Movement of the horizontal portion of 205 in a horizontal arc pivots the leverabout its axis 201 and, depending upon the direction of movement, actuates either the switch 172 or 173. It will be noted from Figure 5 that the horizontal portion of 205 is located close to the right-hand side of the hoist so as to be aligned with the operating arm 207. The showing in Figure 5 is for the mounting of hoists on the right-hand side of the stairway. If the hoist is to be mounted on the left-hand side of the stairway, the operating arm 207 will be on the left-hand side of the rail B.. The present. invention contemplates a lever arrangement whereby the lever 200 may be actuated without interchange of parts in either a right or left-hand installation. Thus, a second lever 209 is pivoted at its right-hand end about an axis 210 generally in the same horizontal plane with the axis 201. This lever extends over the lever 200 and thence downwardly and outwardly into a horizontally extending portion 211 having a slot 212 therein similar to the slot 206. i

The two levers 200 and 209 are slotted generally midwaybetween the two axes 201, 210 as at 213 and a pin 214 slidably extends through these two slots. It will thus be seen that movement of the portion 211 in a righthand direction will effect a left-hand movement of the portion 205 of the lever 200 and vice versa. It will be noted the slots 206 and 212 are generally located symmetrically on opposite sides of the center-line plane through the. rail 'B and the drive shaft 50. With this arrangement, the switches 172 and 173 can be actuated from either side of this center-line plane.

In the embodiment of the invention shown in Figure 5, which, asstated, is a right-hand installation, the lever 209 has a horizontal extension in arm 216 bolted to the portion 211 by means of a nutand-bolt arrangement 217.

A foot pedal 218' is supported on the lower end of an inverted U-shaped member 218 pivoted in a bearing 219 mounted on the upper end of the motor 35. One leg of the member 218 is aligned with the arm 216 and when the pedal 218 is moved to the right as viewed in Figure 5, this motion is transmitted to the lever 209 through the arm 216. Movement of the lower end of the lever 209 to the right pivots the upper end of the arm 202 to the right, thus actuating the start switch 172. t

For a left-handed installation, the arm 216 will be mounted on the portion 205 of the lever 200 and, obviously, the pedal 217 will also be disposed on the opposite side of the motor 35. i

As stated, the arm 207 actuates the lever arm 200 in the form of a short a bidirectional manner to control the starting and stopping of the motor 35. This arm 207 is an angular extension of an operating member indicated generaly by the numeral 220 mounted for pivoting movement on the portion of the base 18 of the rail B extending laterally beyond the top 19 and extending the full length of the rail B. When the member 220 is rotated, the arm 207 moves through an arc to actuate the lever 200, either directly in the case of a right-hand installation orv through the lever 209 in the event of a left-hand installation. The member 220 may take anydesired form or shape but, in the embodiment shown, iscomprised of a round rod 222 which is easily mounted for pivoting or rotational movement about its own axis having a vertical rib 223 extending from its upper side and over its entire length. Sidewise pressure on the rib 223 will cause the member 220 to rotate in a direction corresponding to the direction of the pressure.

The member 220 may be mounted relative to the rail in any suitable manner but the preferred embodiment of the invention contemplates a plurality of fasteners 225 mounted along the rail and coacting with the rod. These fasteners are generally U-shaped in end view and include a base 226 and a pair of spaced parallel extending legs 227 terminating in inturned spaced portions 228. The length of the base is greater than the width of the legs. The right edge of the base 18 of the rail B is provided along its length with a plurality of rectangularly shaped openings 229 of a dimension to just pass the legs of the fasteners 225 but not the base 226. The member 220 generally lays along the upper surface of the base 18 aligned over the openings 229 and the legs 227 extend upwardly through the openings on both sides of the member 220 and the inturned ends 228 extend over at least a portion of the upper surface of the rod 222 but are spaced from the sides of the rib 223.

The rail B, the operating member 220 and the fasteners 225 are readily assembled by first inserting the fasteners in the openings 229 and then inserting the member 220 lengthwise between the legs 227 of the fastener 225. A simple assembly results which is economical to manufacture, is easily assembled and, yet, allows the requisite bidirectional movement of theoperating member 220.

Each end of the member 220 terminates in a cap member 231 having a bore 232 to receive the rod 222 and a slot 233 to receive the rib 223. This cap may be held in assembled relationship with the end of the member 220 in any desired manner such as a set screw not shown, or as will be described.

As will be seen in Figure 8, the right-hand edge of the base 18 of the rail B is provided with slots 234 of a Width and depth to just receive the cap 231, which construction locks the member 220 against longitudinal movement relative to the rail B. The arm 207, as shown, is mounted on this cap at the upper end of the member 222.

The lower end of the operating member terminates in a like cap which has an arm 207 extending laterally across the end of the rail B. This arm is symmetrical about its center point so that it may be used for either right or left-hand installations. A foot pedal 239 is mounted for pivoting action on the lower end of the rail 13 by means of an axle 239, which pedal 239 rests on the arm 207 such that when the pedal is stepped on, the member 220 will be rotated in its fasteners. This rotational movement is transmitted to the operating lever 200 through the arm 207.

The carriage 65 is provided with a pair of spaced lever arms 235, 236 pivoted about axes respectively 235 and 236 in the plane of the base 70 of the carriage. These lever arms extend across the underside of the base 70 in slightly spaced relationship and on the right-hand end as viewed in Figure .27, terminate in downwardly extend ing portions 237, 238 respectively in such a manner as to be disposed on opposite sides of the rib 223. Pivoting of these lever arms 235, 236 causes the downwardly extending portions to engage the rib 223 and rotate the operating member 220. As shown, the members 235 and 236 are disposed essentially in the same plane and extend across the underside of the base 70 with a space or slot 240 therebetween. The right-hand ends of these members 235 and 236, as viewed in Figure 16, are biased toward each other by means of a helical coil spring 242. A stop pin 243 is disposed in the slot 240 to maintain the spacing of the members.

The members 235 and 236 are rotated in their respective planes by control mechanism mounted on the platform 66 and including a finger 245 extending into the slot 240. This control mechanism which will now be described in greater detail serves to actuate the finger 245 in either an upwardly or downwardly direction as viewed in Figure l6to actuate the lever arm 200 on the controls for the power means.

The finger 245 forms an extension on a follower plate 247 pivotally supported for rotation about a horizontal axis on the end plate 120 by a shaft 248. A sleeve 249 about this shaft and welded to the plate 120 and a sleeve 250 also about the shaft 248 and welded to the follower 247 serve to space the follower 247 from the plate 120 in an amount sufiicient that the finger 245 will engage the members 235 and 236 substantially as shown in Figures 16 and 27.

' A foot pedal 252 reciprocably supported on a vertical line of movement on the step by means of a sleeve 253 fastened to the step 115 actuates the follower 247 through a pivoted intermediate follower 254 generally L-shaped in cross section. The lower end of the pedal 252 engages this intermediate follower 254 on one side of the axis 255 of rotation to rotate the follower 254 in a counterclockwise direction. The followers 254 and 247 have inter-engaging surfaces 256 intermediate their respective axes of rotation such that movement of the follower 254 in the direction indicated will rotate the follower 247 in a clockwise direction with the result that the finger 245 will engage and pivot the plate 235 so that'it will, in turn, rotate the control member 220 in a counterclockwise direction to actuate the start switch 172.

The above-described arrangement of the levers is for the right-hand mounting of the hoist. Provision is also made whereby the follower 247 may be employed for the left-hand mounting of the hoist. As previously indicated, the front 116 will become the step for such lefthand mounting. Accordingly, a pedal 252 reciprocably supported on the front 116 by a sleeve 2'53" engages a surface 256 on the follower 247 to rotate it in a clockwise direction when the pedal 252 is depressed.

Whenthe' follower 247 is rotated in a counterclockwise direction, the lever arm 236 will be actuatedto rotate the operating member 220 in a clockwise direction to actuate the stop switch 173. Provision is made for actuating this stop switch 173 from the car C either at the will of the operator or in the event an obstruction should appear in the stairway in the path of the movement of the car.

Thus, as viewed in Figure 22, the left-hand side of the step 115 is provided with an arcuate extension or bumper 259 pivoted at its upper edge to the step 115; In a like manner, the lower edge of the front 116 is provided with a similar arcuate bumper 259 pivoted to thelower edge of the front 116. These bumpers 259 and 259 are so arranged that their lowermost edge will generally be as low as or lower than the car C. Any obstruction on one of the stair treads 14 will thus cause the particular bumper to be pivoted inwardly toward the car at the moment of impact. A rod 260 extends from the inner arcuate surface of the bumper 259 to the follower 247 at a point below its axis such that when the bumper 259 is pivoted toward the car C, the rod 260 will be actuated to the left and the follower 247 moves in a counterclockwise direction. As shown, the left-hand end of the 1? rod 260 is slidably mounted in the plane 262 of the car. The right-hand end of the rod 260 has a reduced portion 263 extending into an opening in a flange 265 on the follower 247 to provide a shoulder which will bear against the flange 265 for the purpose of transmitting the forces involved.

In a like manner, a rod 26% extends from the inner arcuate surface of the bumper 259 to a flange 265 on the follower 247 such that when the bumper 259 is pivoted inwardly, the follower 247 will be also rotated in a counterclockwise direction.

To provide the operator with an emergency stop arrangement, a pedal 267 is mounted on the inboard side of the bumper 259 projecting upwardly therefrom whereby a downward pressure on this pedal 267 will rotate the bumper 259 inwardly toward the car to actuate the follower 247 in a like manner as though the car has struck an obstruction.

it will be noted that the pedal 252' engages the follower 247' directly Whereas the pedal 252 actuates the follower 24? through the intermediate follower 254. The purpose of the follower 254 is to give a reversal of direction to the start movement of the pedal 252. This arrangement enables the pedal 252 to be conveniently located in the middle of the step in a fore-and-aft direction convenientto the operator of the hoist. Obviously, the pedal 252 could be moved so that its line of action was to the right of the shaft 248 so that the intermediate follower 254 could then be eliminated.

As previously indicated, the present invention contemplates an arrangement whereby when the car C is to be brought to a stop either at the end of its travel or intermediate the limits of its travel due to operation of the stop pedal 267, instead of applying conventional braking mechanism which would have to be of a heavy-duty type, the car is brought to a stop by plugging the motor 35 to a stop; that is to say, the motor is energized for rotation in a reverse direction until the instant that it has ceased rotation. A very rapid braking action can then result. The present invention contemplates an arrangement which will sense the stopping of movement of the car in response to this plugging of the motor 35 and, at that instant, deenergize the motor 35 and apply the friction-locking or braking assembly previously described.

in the preferred embodiment of the invention, this sensing of the stopping of the movement of the car C is in the form of an electrical switching arrangement indicated generally at 270 in Figures 3, 5, 9 and 10 included as part of the subassembly 166. Generally, it may be said that this switch 270 is a single-pole, double-throw switch having an intermediate position wherein both contacts are open.

in the preferred embodiment, this switch is comprised generally of a switch arm 272 formed of electrical insulating material and mounted on an extension 273 of the shaft 176 above the bearing 177 so as to extend sidewardly therefrom. The outer end of the arm 272 is provided with electrical contact members in the form of an inverted U- shaped member 274 extending over both sides of the arm 272 and having electrical contacts 275 and 2.75 mounted thereon. These contacts 275 and 275 may be called the movable contacts of the switch. The stationary contacts 276, 27 6' are mounted in spaced relationship a greater distance than the spacing of the contacts 275, 275 on a U-shaped metallic member 277, the base of which is mounted on a right-angled bracket 27S fastened or mounted on the flange 179, which, as previously indicated, is mounted on the base 168' of the subassembly 166. As shown, the member 277 is electrically insulated from the bracket 278 by means of suitable electrical insulation 279.

The switch arm 272 is actuated between its respective stationary contacts 276, 276' by rotation of the threaded .shaft 176 drivingthe arm through a slipping frictional driving arrangement consisting of a ballbearing 281 direction.

18 pressed into a groove 282 in the shaft extension 273 by means of a helical coil spring 283 and an intermediate slidable member 284. The ball, spring and member 284 are all being mounted in a central opening in the arm 272. A threaded screw 285 threaded in the end of the arm 272 enables the compression on the spring 283 to be controlled.

Rotation of the shaft 176 in either direction moves one of the movable switch contacts into engagement with its respective stationary contact and this engagement is maintained so long as the shaft 176 continues to rotate in that At the instant that the motor 35 is brought to a stop by the plugging action above referred to and commences to rotate in the opposite direction by virtue of the energization in the reverse direction, the shaft 176 will also commence to rotate in the opposite direction, thus causing the switch arm 272 to move to engage its other contacts. At this instant, however, electrical contact is broken and other apparatus to be described operates to deenergize the motor 35. Such apparatus includes a relay 2137 (see Figure 31) of conventional construction having an energization coil 28% and normally open contacts 28%: wherein an electrical diagram of the control apparatus for the power means is shown in a schematic manner, the various parts being indicated by like reference characters.

in this diagram, it will be seen that the start switch 172 has a normally open contact 1172a. The stop switch 173 has a normally closed contact 173a. The reversing switch 17 is a snap-action, single-pole, double-throw switch having a pair of contacts 174;! and 17411 which, when connected to the switch arm, connect the motor 35 to drive the car C either down or up respectively. The motor 35 is of the repulsion induction type having a pair of independent windings, a down winding 35d and an up Winding 35a.

For the purposes of describing the operation of the electrical circuit shown in Figure 31, it will be assumed the car has been halted half way in its travel down the stairway. Thus, the follower nut 132 is positioned approximately half way along the length of the threaded shaft 176. The contacts on the switch arm 272 are also out of electrical engagement with the contacts 276, 276'. To restart the car, the depending arm 205 of the lever 200 is moved to the left. This closes the contact 172a to en ergize the relay 2%? and the solenoid brake coil 164, the circuit being traceable from the wire 300 through the now closed contacts 172a, the wire 302, the energization coil 2871; of the relay 287, the wire 303, the closed contacts 172a to the wire 301. Also, energization of the wire 362 completes a circuit to energize the energization coil of the solenoid coil 164 to the wire 303. Energization of this solenoid coil pulls the brake shoe 161 away from the brake drum 160 against the force of the spring 166, thus releasing the brake. Energization of the relay 287 closes its normally open contacts 287a, completing a circuit from the wire 300 to the now closed contact 287a, wire 304, the closed contacts 174d, the wire 3&5, the down coil 35d of the motor 35 to the wire 303 which, as previc-usly indicated, is inergized through the normally closed contacts 173a. Energization of the motor winding 35d causes it to rotate in a direction to permit the car to continue its descension down the stairway. Rotation of the shaft 176 causes the switch arm 272 to move into engagement with one of the contacts 276 or 276, it being assumed for this illustration that the contact 276' is engaged. Closing of these contacts completes a holding circuit for the relay 287 and the lever 200 may be released, thus opening the contacts 172a but without effect.

Rotation of the motor 35 drives the shaft 176 to cause the follower 182 to move downwardly also. The follower 1822 continues to move downwardly as long as the car moves downwardly and, as previously indicated, this follower moves proportionately to the movement of the car. When the follower reaches the lower end of the shaft, it engages and moves the slide 13 until the slide actuates the operating arm 174 of the switch 174. When this occurs, the contacts 174:: of the switch 1'74 are engaged, thus energizing the wire 3% which connects to the Winding 3511 of the motor Energization of the winding 35 attempts to drive the motor in the reversed direction so that a very rapid braking effect of the motor rotor occurs. At the instant that the motor rotor reaches a full stop and commences to reverse its rotation, the rotation of the shaft 176 is also reversed. At this instant, the switch arm 272 also moves in a reverse direction and breaks its contact with the contact 276'. The moment that this contact is bro-ken, the energization circuit for the relay 287 is broken, allowing its normally open contact to reopen, thus deenergizing the winding 351:.

Opening of the contact 276 also deenergizes the solenoid coil 164, allowing the spring 166 to again advance the brake shoe 161 against the brake drum 160. Thus, the motor rotor is prevented from rotating, but it will be appreciated that this engagement of the brake shoe occurred at the instant that the motor was stopped. Thus, the brake does not have to dissipate any mechanical energy as would be the case if it were engaged while the motor 35 were rotating.

If at any time during the course of movement of the stairway down the stairs the contacts 172a of the stop switch 173 are opened by moving the lever arm 2% to the right, the holding circuit of the relay 287 is broken to deenergize the motor and engage the brake 161 to stop the car.

It will be appreciated that if the stop switch 173 is actuated any time during the course of the movement of the stairway'in one direction when the start switch 1720 is subsequently actuated, the car C will continue to move in the same direction as before it was stopped.

It will also be appreciated that if the start switch 172 is continuously maintained closed, the car will simply approach the lower limit of its travel when the switch 174 is then actuated and the car will simply reverse its direction of travel.

To enable the rail to accommodate any length of stairway, the rail is normally supplied in sections. These sections are laid end to end and a flat metal plate 310 is bolted to the bottom side thereof using the spaced threaded openings 33 on the underside of the members. As shown, the plate 310 has slotted openings 311 so that regardless of where the cut off of the one member occurs, the threaded openings 33 may be made to match with the openings 311.

The primary function of the plate is simply to hold the two members of the rail B in assembled relationship.

The operating member 22!) is supplied in two sections. A union 231 in the form of a split sleeve fits over the adjacent ends to hold them in assembled relationship. This sleeve fits into the slot 234 on the upper uncut end of the lower member as shown in Figure 15.

It will be noted that the slots 234 are generally quite close to the ends of the members leaving a small tab 312 at each end of the rail B. After the operating member 220 with the caps 231 and sleeve 231 have been assembled as previously indicated, the tab 312 at the lower end of the rail B is bent upwardly with a pair of pliers or the like, thus preventing disassembly of the operating member 226 from the rail 13. With this arrangement, no setscrews are required for the caps 231 or sleeve 231'.

A handle indicated generally at 314 and mounted on the inboard side of the car C is also provided. This handle in the embodiment shown is generally in an inverted U shape comprising a base 315, a pair of depending legs 316 and 317 which are fastened to the car C.

The leg 316 terminates in a flattened right-angle portion 318 which extends through an opening 319 in the rightband edge of the step 115 as viewed in Figure l8 and thence is bolted to the underside of the step 115 by bolts 320 extending through openings 321 in the step and threaded into the right-angle extension 318.

The le' 31", terminates in a flattened portion 322 extending through an opening 323 in the left-hand side of the step 115 as viewed in Figure l8 and is bolted to the upper edge of the front 116 by means of bolts 324 extending through openings 325 in the upper portion of the front 116 and threaded into the flattened portion 322.

it will be noted that the opening 319 in the step 115 is of a width and depth to enable the back edge of the step to clear the rail B while still being in close proximity to the upper corners of the treads as the car C is moved up and down the stairway. in a like manner, the inboard lower corner of the front 116 is similarly cut away to provide an opening 319. A pair of bolt openings 321 are provided in the front 116 adjacent the lower edge and the opening 319' to receive the mounting bolts 320 when the hoist is mounted in a left-hand installation on the stairway. As previously pointed out, the car C is so oriented that the front 116 becomes the step when a left-hand installation is made. in a like manner, the outer inboard corner of the step 115 is provided with a pair of openings 325' identically arranged with the openings 325 so that for left-hand installations, the flattened portion 322 may 'be fastened to the underside of the step 115. it will thus be seen that the ear is completely reversible without any structural changes therein.

With the arrangement shown, it will be appreciated that the level of the step 115 when the car C is in its lowermost position will still be a substantial distance above the floor 11. The preferred embodiment of the invention contemplates an auxiliary step 330 supported on brackets 331 mounted on the sides 1%, 121 of the platform by threaded bolts 332 extending through holes in the brackets into threaded openings in the respective sides. The threaded holes into which these bolts 332 extend are not shown in the drawing but corresponding holes 333' in the side 121 and similarly located holes in the side 129 are provided for mounting the step 330 in a left-hand installation.

The power means D are enclosed in a housing 335 open at the bottom which slips over and entirely covers the motor 35, the subassembly 166 and the gear-reduction unit 37. The inboard lower corner of the front and back of this housing is cut away to provide an opening 336 through which the upper end of the rail B may extend into the housing 335 to have axis with the power means D. By providing a cut away in both the front and back sides of the housing 335, it will be appreciated that the housing can be readily reversed for either right or left-hand installations.

The lower edge of the outboard side of the housing 335 is also cut away as at 337 to provide a clearance for the supporting member for the foot pedal 217.

To operate the hoist, an operator need only step onto the step 115 and depress the pedal 252 with his foot whereupon the motor is energized to cause the car C to automatically advance to the opposite end of the stairway and, there, automatically stop. During the course of the travel if the operator desires to stop the car, he need merely step on the pedal 267 to actuate mechanism to stop the motor 35 and quickly bring the car to a stop. In the event that the car is at the opposite end of the stairway from where the operator is, he need merely depress the pedal 239 with his foot, whereupon the motor 35 is energized in a direction to advance the car to that end of the stairway. In the event that the car is at the bottom of the stairway, the operator need merely move the pedal 217 to the side to actuate the motor to bring the car to the upper end of the stairway. The sequence of events following the actuation of any one of these pedals has previously been specifically outlined.

It will be appreciated that the hoist described can just as well be mounted on the left-hand side of the stairway by reversing all of the parts and employing the auxiliary bolt or screw openings provided for this purpose. It

be appreciated that in no event are there any extra parts required for this reversibility feature nor are there any parts which are useable only for mounting on one side or the other. This feature may be said to be obtained by having all parts which do not need to be reversed for rightand left-hand mounting completely symmetrical about a center-line plane extending the length of the stairway and for all parts which must be reversed for the rightand left-hand mounting to be symmetrical about a generally center-line plane perpendicular to the length of the stairway.

It will be noted that except for the car itself, there is no obstruction in the middle of the stairway such as a rail for otherwise interfering with the use of the stairs. This particular feature is emphasized by the modified embodiment of the invention shown in Figures 32 to 34. Here, a car E is provided having a pair of skid members, an inboard skid member 350 fastened to the lower side of the car and having a length several times longer than the maximum length between adjacent stair treads. The outboard side of the car is provided with a skid 351 of a construction similar to that described in the preferred embodiment of the invention. The upper corners of the lips 15 of the stair treads are provided with pad 146 preferably formed of nylon material, the same as that described with reference to the preferred embodiment. The lower and inboard side of the skid 350 is provided with a nylon sole 353 and an L-shaped rail of nylon material 354 is suitably fastened along the right-hand side of the stairway as viewed in Figure 32 either by nailing or by means of clamps such as described in the preferred embodiment. An electric drive motor 355 and a drum 356 driven by the motor 355 are mounted on the car. A cable extends through an opening in the upper side of the car to a point adjacent the top of the stairway and closer to the wall and the point from which the cable emerges from the car E. When the motor 355 is energized to advance the car up the stairs, the cable 357 is wound onto the drum. Because of the angle shown, the car will be continuously urged inwardly toward the right-hand side; that is, into engagement with the upstanding portion of the guide rail 354. Because of the lentgh of the skid 350, the car E is prevented from twisting due to any weights which might be ofiset from the center line of the cable 357. With such an arrangement which, of course, is far more simpler than that described in the preferred embodiment, a stairway elevator may be provided which is extremely simple in construction but still satisfactory in operation. Because of the very low-friction coeflicient between the nylon members, the car B will move in practically a friction-free manner. Of course, the elevator will not have the satisfactory appearance. of that shown in the preferred embodiment nor will the controls be as simple. However, the feature of the outboard skid and the tremendous advantages which it gives is fully emphasized by this embodiment of the invention.

'Figure 35 shows an alternative embodiment of a control arrangement for the hoist which, in some instances, has Proven more desirable in practice than the control circuit shown in Figure 31. The principal attributes of the circuit shown in Figure 35 is the ability to use a more or less conventional split-phase type alternating-current motor which is much cheaper than the type of motor shown in Figure 31. Additionally, the arrangement shown provides an improved and smoother starting of the car in the downward direction and an improved and smoother stopping of the car in the upward direction. In the circuit shown, the motor 35 has a running winding 35r and a starting winding 35s, both of conventional charac teristics, the starting winding 35s having a capacitor 360 connected in electrical series therewith by a conductor 361.

A follower 182' similar in function to the follower 182 of Figure 31 actuates a normally closed stop switch 1 363 at the upper limits of its travel and closes the normally open contacts of a switch 364 at the lower limits of its travel. Thus, the switch 363 has an operating arm 363 engaged by an upwardly extending arm 365 on the follower 182 and the switch 364 has an operating arm 364 engaged by a downwardly projecting arm 366 also mounted on the follower 182.

In a right-hand installation of the hoist, the car moves in one direction for a given direction of rotation of the motor 35. For example, a clockwise rotation of the motor will move the car in a downward direction. For a left-hand installation, however, this situation is exactly reversed and a counterclockwise rotation. of the motor 35 will move the car in a downward direction. As it is always desired that the follower 182 move in a direction correspondingto the direction of movement of the car, means are provided whereby at the time of installa tion the mechanical connection between the motor 35 and 35 and the shaft 176 may be reversed. Thus, the shaft 176 may be direct driven for a right-hand installation or through an idler gear 370 engaged with a gear 371 fastened to the lower end of the shaft 176.

To describe the operation of the modified embodiment,

it will be assumed that the car is stopped at the bottom of the hoist. Thus, the follower 182 will be at the lower end of its travel with the mm 366 engaging the switchactuating arm 364 to close the contacts of the switch 364. In a like manner, the brake energizing coil 164 is not energized and the brake shoe 161 is in engagement with the brake drum 160. When it is desired to move the car upwardly, switch 172a is closed. This completes a circuit from the wire 300 to wire 373 and the energization coil 2871) of the relay 287 to Wire 3431. Energization of the relay 287b closes its normally open contacts 287a, thus energizing the wire 374. Energization of the wire 3'74 energizes the running winding 35r and the brake control coil 164. Also, the starting winding 35s is energized through the closed contacts of the switch 364, wire 375, the capacitor 360 and the wire 361. Thus, the motor 35' is energized to drive the car upwardly along the rail. As the motor 35 commences to rotate, the arm 272 is moved into engagement with one of the contacts 276 or 276, depending upon the direction of rotation of the shaft .176. This completes a holding circuit for the relay 267, the circuit being traced from the wire 374, the closed contacts 276 or 276, the wire 376, the closed contacts of the switch 363, wire 377, the closed contacts 173a to the wire 373. The lever 200 may now be released, thus opening the contacts 172a but without effect because the contacts 287a remain closed.

As the motor 35 continues to rotate, the follower 182' is driven or advanced upwardly along the shaft 176 at a speed corresponding to the speed of movement of the car. When the follower 182' reaches the point where the arm 365 engages the arm 363 of the switch 363, the contacts thereof are opened, thus breaking the energize.- tion circuit for the relay 287. The contacts 28711 are thus opened and the energization of the motor 35' removed. The car will coast to a stop. ,At the same time that the motor 35' is deenergized, the coil 164 is deenergized thus also engaging the brake shoe 1611. The car will thus be locked in its upward position.

When it is desired to move the car downwardly, the switch 172a is again closed by actuating the lever This energizes the relay 287 as previously described, which closes the contacts 287a, thus energizing the running winding 351' and the brake control coil 164. it will be noted that the starting winding 35s is not energized for the downward movement of; the car. Release of the brake 161, howevenpermits the motor to rotate under the weight of the car and the motor quickly comes up to its full drive speed and then locks into synchronism with the frequency of the current in the running winding 35r. It will be noted that by not using the starting winding 35s, a very smooth and easy start of the car in the downward direction results.

Should the operator desire to stop the car for any reason in the path of its downward movement or in its upward movement, the arm 200 is actuated in a clirection to open the stop switch contacts 173a. Opening of these contacts breaks the holding circuit for the relay 287 and thus opens its contacts 2370. The brake 161 is thus engaged and the motor 35 deenergized. The car will quickly come to a stop under the influence of the brake 161.

In the embodiment of the invention shown in Figure 35, the switches 363 and 173 are in electrical series relationship. It is to be noted that it is possible to combine these two switches into one, having 'an arm to be actuated either by the lever 200 or the arm 33-65.

In the event the car is stopped midway in its travels down the stairway by opening of the switch 173, when the start switch 172 is again closed, the car will move in a downward direction only, the motor starting to rotate as above described with reference to starting the car from the uppermost point of its travel.

As the car continues to move down the stairway, the follower 182 also moves down the threaded shaft 176. This movement continues until the arm 366 engages the arm 364 to close the switch 364. When the switch 364 is closed, the starting winding 35s becomes energized to cause the motor to rotate in a direction in opposition to that of the downward movement of the car. braking results, bringing the car quickly to a stop. At the instant that the motor commences to rotate in the opposite direction, the contacts 276 or 276' are opened to thus break the energization circuit for the relay 287 and thus the motor 35' becomes deenergized along with the deenergization of the relay coil 164. Thus, this latter engages the brake 161 and the car is held in this stopped position.

The arms 365 and 366 are both adjustably positioned on the follower 182 by means of setscrews 380 whereby the automatic stopping points of the car may readily be adjusted.

It will thus be appreciated that embodiments of the invention have been described which accomplish all the objects heretofore set forth and others and provides a hoist particularly adapted for installation in stairways, which can be very quickly installed and easily removed without leaving scars or the like, which is cheap to assemble from readily manufactured parts on a mass-production basis and which would be readily acceptable in the modern home.

Having thus described my invention, 1 claim:

1. In combination with a stairway having a plurality A dynamic I 1 face being continuous and smooth for a distance at least greater than the distance between adjacent stair treads, said surface progressively engaging adjacent stair treads as the car moves up and down a stairway guided by said rail member to resist vertical forces on said car transversely spaced from said rail member.

2. The combination of claim 1 wherein said second means is in the form of a skid and has antifriction means on the lower surface thereof.

3. The combination of claim 2 wherein said antifriction means comprise rollers and an endless belt supported on said rollers, said belt engaging said treads.

4. The combination of claim 2 wherein said antifriction means include a material on said second means which will have a low coeflicient of friction with the lips of said stairway.

5. The combination of claim 4 wherein at least the corners of said stair tread have an antifriction material fastened thereto in the path of movement of said second means.

6. The combination of claim 1 wherein means are provided for adjusting the angle of said second means relative to said car whereby the same car may be readily adjusted for use on stairways of different slopes.

References Cited in the file of this patent UNITED STATES PATENTS 1,014,216 Gale Jan. 9, 1912 1,085,987 Lindquist Feb. 3, 1914 1,148,323 Kendall July 27, 1915 1,768,650 Wood July 1, 1930 1,838,204 Wood Dec. 29, 1931 1,993,309 Rubin Mar. 5, 1935 2,097,075 Muller Oct. 26, 1937 2,207,544 Knudsen July 9, 1940 2,212,064 Elliott Aug. 20, 1940 2,212,388 Cheney Aug. 20, 1940 2,241,798 Weiss May 13, 1941 2,306,816 Larson Dec. 29, 1942 2,507,887 Cheney May 16, 1950 2,619,195 Scott Nov. 25, 1952

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