US2619195A

US2619195A - Elevator for invalids

Info

Publication number: US2619195A
Application number: US176425A
Authority: US
Inventors: Scott George Philip
Original assignee: ELECTRO LIFT CHAIR CORP
Current assignee: ELECTRO LIFT CHAIR Corp
Priority date: 1950-07-28
Filing date: 1950-07-28
Publication date: 1952-11-25
Anticipated expiration: 1969-11-25

Description

Nov. 25, 1952 p, SCOTT 2,619,195

ELEVATOR FOR INVALIDS Filed July 28, 1950 3 Sheets-Sheet 1 INVENTOR.

Geo/ye /Q Jaw/f WWW ATTORNEYS Nov. 25, 1952 G. P. SCOTT 2,619,195

ELEVATOR FOR-INVALIDS Filed July 28, 1950 3 Sheets-Sheet 2 77 7 j g a INVEN TOR. 09a Jaw/i ATTORNEYJ Nov. 25, 1952 P SCOTT 2,619,195

ELEVATOR FOR INVALIDS Filed July 28, 1950 3 Sheets-Sheet 3 I N V EN TOR.

eoxye J60 2 ATTORNEYS Patented Nov. 25, .1952

UNITED STATES PATENT OFFICE.

ELEVATOR FOR IN VALIDS George Philip Scott, Kansas City, Mo., assignmto' Electra Lift Chair Corporation, Kansas City, Mo a corporation of Missouri Application July 28, 1950, Serial No. 176,425-

19 Claims. 1

This invention relates to stair elevators for carrying incapacitated persons up and down stairs, the present invention being. an improvement in the structure disclosed in my copending application on Elevator for Invalids, filed September 16, 1948, Serial No. 49,467.

The principal object of the present invention is to provide for safety of the operator and prevent damage to the mechanism in case of improper manipulation or mechanical failures.

Other objects of the present invention are to provide a pulley and cable arrangement which keeps the chair moving freely along the track and. permits use of a less expensive power unit;

to provide means for opening the power circuit to the motor for preventing unwind of the cable from the winding drum upon setting of the automatic safety brake incidental to cable breakage or by slack in the cable when the chair reaches the lower endof the track; to provide an improved mounting of the entire self-contained unit on a pair of stairs; and to provide a shorter length unit and yet attain the same relative chair travel.

In accomplishing these and other objects of the invention hereinafter pointed out, I have provided improved struc'ture,.the preferred forms of which are. illustrated in the accompanying drawings wherein:

Fig. 1 is a sectional perspective view of a porti'on of. a stairway equipped with an invalids elevator constructed in accordance with the present invention.

Fig. 2 is a. front elevational view of the elevator with. parts of the chair broken away to better illustrate the construction.

Fig. 3 is a diagram of the electric circuit supplying the motor which efiects movement of thechair on the track.

Fig. 4 is a side elevational view of the elevator, parts being shown in section.

Fig. 5 is a fragmentary perspective view of a portion of the track and part of the invalids chair, particularly illustrating the automatic brake mechanism in the normal released position thereof as when the cable and operating mechanisms are in proper operating condition.

Fig. 6 is av similar view showing the brake set incidental to. breakage of the cable.

Fig. 7 is a fragmentary perspective section of the upper portion of the track, particularly illustrating the automatic switch for opening the. motor circuit in case. of improper operation of the controller lever.

, Fig. 8 is a perspective view of the upper end of a modified form of the elevator.

Fig. 9 is a fragmentary view illustrating the control switch arrangement used in the form. of invention illustrated in Fig. 8.

Referring more in detail to the drawings:

I designates a stairway comprising a series of steps composed of conventional treads and risers 2 and 3 whereon aperson may climb froma lower floor i to an upper floor or landing 5. Mounted on the stairway at one side thereof is. an invalids elevator constructed in accordance with the present invention. The elevator is a self-contained unit including av track 5-,. a carriage or chair 7 and the operating mechanism therefor.

The track 6 comprisess'paced rails 8-. and 9? that are disposed on the nosings H). of the. stair treads 2. The rails preferably comprise channel shape members having vertical webs II. and upper and lower inwardly facing flanges i2 and [3. The rails are of sufiicient length to extendv from the lower floor i to a point above the landing 5 to permit movement of the. elevator chair 1 com pletely onto the landing. The lower end. of the rails are interconnected by a plate [4 that lies flatly against the floor and is adapted to be secured by means of a finish nail I5 driven into the floor through one. of. a series. of openings 16 in the plate. The upper ends of the rails are connected by a cross bar I? and by a housing l8 which forms an enclosure shield for a pulley l9 and a spring actuated reel 20.. The. housing also carried a plug-in socket 2i and a control switch 22 for a. purpose later described- I Fixed to the underside of the rails at a point above the landing are legs 23 to support the overhanging upper end of the track under weight of the chair and invalid when the chair is at the upper end of the track. If desired, the legs 213 may be secured to the landing by fastening. devices 2.4.

The chair generally designated 1 includes spaced side frames 25' and 26 each having lower rails 21 carrying spindles 2'8 and 29 at the ends thereof. The spindles mount wheels 30 and 3| that roll between the flanges I2 and [-3 of the

track rails

8 and 9. Fixed to the front ends ofthe rails 21 are vertical members 32 cooperating with shorter members 33 at the opposite ends. in supporting horizontal rails 34 carrying a seat 35-. The frames thus described are covered at the outer sides by panels 36 and. are inter-connected at the front by a panel 37 to form an enclosure for the power mechanism later described and to provide a rigid chair structure.

The seat 35 may project from the side of the chair frame as indicated at 38', Fig. 1, to mount a starting and reversing switch 39 thereunder. The seat may be provided with a back rest 40 and a side arm 4| as shown in Fig. 1. A foot rest 42 may also be provided which extends across the front panel of the chair and adds rigidity to the frame.

It is thus obvious that the chair is supported on the track by wheels 30 and 3| and is adapted to move between the rails from one floor level to the other.

Fixed to and extending between the lower rails 21 of the side frames 25 and 26 are base plates 43 and 44 respectively carrying a motor 45 and a speed reducer indicated by the housing 46. The motor 46 is secured to the base plate 43 by fastening devices such as bolts 41 while the speed reducer is fixed to the base plate 44 by studs 43, the studs extending through lateral flanges 49 on the housing 46 and carrying jam nuts 59 and engaging the respective sides thereof as shown in Fig. 3.

By adjusting the

jam nuts

59 and 5|, the power input shaft 52 of the speed reducer is brought into registry with the armature shaft 53 of the motor for connection by a flexible coupling 54. The power output shaft 55 of the speed reducer extends laterally and mounts a winding drum 56 as shown in Fig. 2, the outer end of the shaft 55 being mounted in a suitable bearing on the adjacent side frame 26.

Connected with the drum 56 is a cable 51 that winds thereon and operates under a guide pulley 58 having sliding support on a shaft 59 so that the pulley travels back and forth on the shaft as the cable winds and unwinds from the drum for moving the chair from one floor to the other as later described. The cable, after passing under the guide pulley 58 passes under and over the pulley l9 and returns to connect with a part of the chair by means of a clamp 66.

It is thus obvious that when the winding drum is rotated in a direction to wind the cable thereon, the chair is carried upwardly along the track and when the cable is unwound from the drum, the chair is lowered on the track.

As above stated, the motor 45 is of the capacitor type and is adapted to be reversed to change the direction of travel of the carriage by means of the starting and reversing switch 39 previously mentioned, the operating lever 6| of the switch being under control of a person seated on the chair.

An electrical current is supplied to the switch 39 by way of a flexible conductor 62 that is carried by the spring wound reel and which is connected in circuit with the plug-in socket 2|. The switch 39 is connected with the motor through conductors 6364 and 6566, for example, when the conductor 63 is in circuit, the motor is actuated in the direction to raise the chair on the track and when the conductor 64 is in circuit the motor is rotated in a reverse direction to lower the chair on the track.

In order to automatically stop the chair when it reaches its upper and lower positions on the track, I have provided limited switches 6! and 68 in the

conductors

63 and 64. These switches may be of any suitable type, but the actuating arms 69 carry wheels 10 and H respectively that are adapted to engage cams I2 and 13 located at the upper end of the rail 8 and at the lower end of the opposite rail 9 respectively as best shown in Fig. 1.

As above pointed out, motors of this type are apt to continue their rotation in the same direction upon failure of the limit switches or even after one or the

other switches

61 and 68 have been opened. Should the motor continue to operate after the upper limit switch has broken the circuit, the chair will jam into the mechanism at the upper end of the track, thus causing damage to the mechanism and perhaps result in injury to the occupants of the chair. This difficuity may have been caused, for example by the operator becoming excited and swinging the control lever El 01: the switch 39 through neutral and into reverse position before the armature of the motor can reverse its rotation. To avoid any ill effects resulting from such operation one lead 14 of the current supply conductor 62 leading to the starting and reversing switch 39 is provided with the switch 22 that is normally closed to render the circuits effective; however, should the carriage tend to continue its movement when it reaches the top position on the track, the switch 22 is automatically actuated to stop the chair. This is enacted by attaching a collar 15 to the dead end of the cable at a position shown in Figs. 5 and 6. Sleeved on the cable and having one end seated against the collar is a coil spring 16, the upper end of which carries a bumper 1'! that is resiliently held in position for engaging the actuating arm 18 of the switch 22 in case the chair should move beyond its upper normal limit of movement. For example, if the chair should continue to move from its position shown in Fig. 4 the bumper '17 will engage the switch arm 18 and open the circuit so that regardless of the position of the starting and reversing switch lever 6!, current is shut off to the motor circuits and the motor ceases to operate until the chair is backed to its normal upper position. It is thus obvious that the switch 22 and related mechanism provides a safety factor which permits the use of a motor of the character described. After the switch 22 has been opened, it is necessary to grasp the bumper TI and compress the spring sufficiently to allow the switch arm I8 sufficient room to permit the switch to close and reestablish flow of current to the control switch.

The shaft carrying the guide pulley 58 constitutes a part of a brake mechanism and has the ends thereof journalled in bearings 19 and that are carried by the members 33 of the side frames of the chair as best shown in Fig. 5. The ends of the shaft project through the bearings and carry eccentric clamps 8| and 82 that are fixed to the shaft so that the peripheries 83 thereof are retained out of engagement with the upper faces of the track rails by tension in the cable 57 which acts against a coil spring 84 having one end fixed to a part of the chair frame and its opposite end attached to an enlargement 85 on brake shaft as shown in Fig. 5. Extending radially from the shaft 59 is an arm 86 carrying a wheel 81 that engages the dead end of the cable as shown in Fig. 5. The coil spring thus holds the Wheel 81 in contact with the cable and the tension in the cable opposes further movement by the spring so that the clamps cannot swing into braking contact with the track rails; however, should the cable break or become slack due to failure of some part of the power mechanism, the spring comes into play to effect movement of the shaft sufficiently to bring the knurled surfaces of the clamps into braking engagement with the track rails to anchor the chair and stop descent thereof.

In case the controller is immediately shifted to reverse when the chair reaches the lower end ofthe track, the motor may continue the same direction of rotation and means is therefore provided for opening the current supply to the control switch. If this means were not provided the cable would continue to unwind after the chair has reached the end of the track and if the control switch is left in reverse position the cable will unwind completely and then rewind on the reel which starts the chair toward the top of the track. This is prevented by a switch 88 that is connected in the current supply conductor 62 and operated upon rocking of the brake shaft incidental to initial slacking of the cable. The switch 88 is preferably of the mercury type and is mounted directly on the shaft to rock therewith when the cable starts to slack. It is obvious that the mercury switch 88 also actuates in case of cable breakage or for any other reason causing the cable to slack.

Assuming that the elevator is assembled as a self-contained unit as described, it is moved into position to rest upon the nosing of the stair treads. The fastening devices I and 24 are then inserted after which a cord from any convenient light socket is plugged into the socket 2! to complete the installation. The elevator is now ready for operation. Assuming that the chair is at the lower end of the track, the invalid seats himself on the chair and moves the control lever SI of the starting and reversing switch 39 in the direction to efiect actuation of the motor for winding the cable 51 on the drum 56. While the chair is resting at the bottom of the track, the switch 58 is held open by the cam '53 but as the roller leaves the track the switch 68 closes. The chair continues to move toward the upper end of the track as long as the Operator retains the control lever 61 in position to energize the motor in the winding direction. However, the operator may stop the ascent of the chair at any point along the track upon moving the control lever to neutral position. When the carriage reaches its uppermost position, the switch 67 is opened by the cam 72 which results in breaking the circuit thereby stopping the motor and chair.

Should the operator suddenly move the control lever through neutral to reverse position, the motor will continue to operate and in the same direction, but as soon as the spring pressed bumper Tl strikes the control arm 18 of the switch 22, the switch is opened and will immediately stop the chair regardless of the position of the control lever.

When the invalid desires to return to the first floor level the position of the control lever 61 is reversed so that the motor rotates in a reverse direction and allows the cable to unwind from the drum and pay out the cable over the pulleys 58 and I9 and permit lowering of the chair, under braking action of the speed reducer, to its position at the lower floor level. Should the motor continue to operate after the chair has reached the lower fioor level, the cable slacken and effect rocking movement of the brake shaft so that the mercury switch 88 opens the current supply circuit as above described.

Should the cable break or become slack, the spring B l will immediately swing the eccentric clamps int engagement with the track to stop descent of the carriage.

After setting of the brake mechanism the eccentrics 8| and 82 are manually released to permit return to normal positionand reestablish a current flow through the mercury switch 88.

The track illustrated in Fig. 8 permits a shorter overhang of the upper .end of the track-and at the same time allow fullmovement of the chair. This is made possible by locating the Spring wound reel 20 for the flexible conductor 62 below the track and out of the way of. the carriage, and by providing a pulley 89 to change the direction of the conductor and keep it in parallel alignment with the. track. In this modi-i fication the switch22 is carried in properposi-i tion, on a bracket 90 carried on a cross bar Bl of supporting frame 92 for the projecting portion of the track, to be actuated by a lug 93 depending from the underside of the carriage. The pulleys 89 and I9 are mounted on the cross bar I! and the reel' 20 on a cross bar 94 that connects the legs 95 of the supporting frame 9!.

From the foregoing, it is obvious that I have provided an elevator for invalids which permits the use of a capacitor type motor without endangering the operator or the mechanism even should the operator improperly manipulate the control lever.

It is also obvious that I have provided a simple and inexpensive brake mechanism which effectively stops the chair in any position along the length of the track incidental to failure of the cable or any part of the power mechanism. It is also obvious that should the cable break when the motor is being operated in a direction to unwind the cable the mercury switch is effective in opening the motor circuit and the cable remains wound on the winding drum.

What I claim and desire to secure by Letters Patent is:

1. An elevator of the character described in-.- cluding a track adapted for support on a stairs, a carriage movable along the track, means for actuating the carriage along the trackincluding a reversible motor, a control switch on the carriage, electric circuits connecting the control switch with the motor, a circuit supplying current with a control switch, a switch in said last named circuit and located at the upper end of said track, and means movable with the carriage for engaging the last named switch to open circuit to the control switch.

2. An elevator of the character described in cluding a track adapted for support'on a stairs, a carriage movable along the track, means for actuating the carriage along the track including a reversible motor, a control switch on the carriage, electric circuits connecting the control switch with the reversible motor, limit switches on the carriage and connected in said circuits, means at the respective ends of the track and engageable by the limit switches for stopping the motor, a circuit supplying current .to the control switch, a main switch in said last named circuit and located at the upper end of said track, and means movable with the carriage for engaging the last named switch to open circuit to the control switch.

3. An elevator. of the character described in-- cluding a track adapted for support on a stairs, a carriage movable along the track, a winding drum on the carriage, a pulley at the upper end of the track, a cable operating over the pulley and having one end wound about the winding drum and the other fixed to a part of said carriage, a motor on the carriage, a speed reducer connecting the motor with the winding drum, and means for supplying current to the motor.

4. An elevator of the character described in-' cluding a track adapted for support on a stairs,

a carriage movable along the track, a winding drum on the carriage, a pulley at the upper end of the track, a cable operating over the pulley and having one end wound about the winding drum and the other fixed to a part of said carriage, a motor on the carriage, a speed reducer connecting the motor with the winding drum, means for supplying an electric current to the motor, a main switch in said electric current supply means, means mounting the switch at the upper end of the track, and means movable with the carriage and adapted to engage the main switch for opening the current supply to said motor.

5. An elevator of the character described including a track adapted for support on a stairs, a carriage movable along the track, a winding drum on the carriage, a pulley at the upper end of the track, a cable operating over the pulley and having one end wound about the winding drum and the other fixed to a part of said carriage, a reversible motor on the carriage, a speed reducer connecting the motor with the winding drum, a control switch on the carriage, circuits connecting the control switch with the reversible motor, a spring actuated reel fixed to the upper end of the track, a flexible conductor wound on the reel and connecting the control switch with a current supply, a switch at the upper end of the track having an actuating means adjacent said cable, and means on the cable for engaging said actuating means for opening the circuit to the controller.

6. An elevator of the character described in cluding a track adapted for support on a stairs, a carriage movable along the track, a winding drum on the carriage, a pulley at the upper end of the track, a cable operating over the pulley and having one end wound about the winding drum and the other fixed to a part of said carriage, a reversible motor on the carriage, a speed reducer connecting the motor with the winding drum, a control switch on the carriage, circuits connecting the control switch with the reversible motor, a spring actuated reel fixed to the upper end of the track, a flexible conductor wound on the reel and connecting the control switch with a current supply, limit switches on the carriage and connected in said circuits which connect the controller with the reversible motor and hav- Ll ing actuators, limit switch actuating means at the respective ends of the track, a switch at the upper end of the track having an actuating means adjacent said cable, and. means on the cable for engaging said actuating means for opening the circuit to the controller.

7. An elevator of the character described including a track adapted for support on a stairs, a carriage movable along the track, a winding drum on the carriage, a cable drum and having connection with the upper end of the track and wound on the winding drum, a reversible motor on the carriage having a driving connection with the winding drum, brake means on the carriage and adapted to engage the track, means engageable with the cable to hold said brake means out of engagement with the track, a spring connected with said brake means to maintain said contact with the cable and to move said brake means into engagement with the track upon yielding of the cable, a controller on the carriage and connected in circuit with the motor, a supply circuit connected with the controller, and a switch having connection with said brake means for opening 8 the supply circuit responsive to movement of the brake means.

8. An elevator of the character described including a track adapted for support on a stairs, a carriage movable along the track, a winding drum on the carriage, a cable wound on the winding drum and having connection with the upper end of the track, a reversible motor on the carriage having an operating connection with the winding drum, 9, rock shaft on the carriage and having eccentrics adapted to engage the track, lever means on the shaft engageable with the cable to hold said eccentrics out of engagement with the track, a spring connected with said lever means to maintain said contact with the cable and to move said eccentrics into braking engagement with the track upon yielding of the cable, a controller on the carriage and connected in circuit with the motor, a supply circuit connected with the controller, and a switch actuated by said shaft and connected in the supply circuit for opening the supply circuit responsive to movement of the eccentrics into engagement with the track.

9. An elevator of the character described including a track adapted for support on a stairs, a carriage movable along the track, a winding drum on the carriage, a cable wound on the winding drum and having connection with the upper end of the track, a reversible motor on the carriage having an operating connection with the winding drum, a rock shaft on the carriage and having eccentrics adapted to engage the track, lever means on the shaft engageable with the cable to hold said eccentrics out of engagement with the track, a spring connected with said lever means to maintain said contact with the cable and to move said eccentrics into braking engagement with the track upon yielding of the cable, a controller on the carriage and connected in circuit with the motor, a supply circuit connected with the controller, a switch actuated by said shaft and connected in the supply circuit for opening the supply circuit responsive to movement of the eccentrics into engagement with the track, and a second switch in said circuit engageable by part movable with the carriage to open said second switch.

10. An elevator of the character described including a track adapted for support on a stairs, a carriage movable along the track, means for actuating the carriage along the track including a reversible motor, a control switch on the carriage, electric circuits connecting the control switch with the reversible motor, limit switches on the carriage and connected in said circuits, means at the respective ends of the track and engageable by the limit switches for stopping the motor, a circuit supplying current to the control switch, and means in the last named circuit cooperating with means on the carriage for stopping the motor when the motor continues to operate because of failure of the limit switches to open the control switch.

GEORGE PHILIP SCOTT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,043,83 i Hinkel Nov. 12, 1942 2,528,265 Cretors Oct. 31, 1950