US2245072A - Automatic door for elevator hatchway openings - Google Patents

Description

- June 10,, 1941.. N. GUILBERT, JR 2,245,072

AUTOMATIC DOOR FOR ELEVATOR HATGHWAY orrmmes Filed July 2, 1940 INVE/V 7'01? w/ TNESS Wren/vs) Patented June 10, 1941 AUTOMATIC DOOR FOR ELEVATOR HATCHWAY OPENINGS Nicholas R. Guilbert, Jr., Chestnut Hill, Pa.

Application July 2, 1940, Serial No. 343,521

Claims.

This invention relates to means for automatically actuating the doors for the openings in elevator hatchways, and is particularly adapted for use with elevators of the character commonly employed for transporting articles of merchandise and the like between different floor levels in restaurants, retail stores and generally similar establishments and which are known as dumb-waiters.

In such elevators the car is arranged to travel in a vertical hatchway having spaced openings proximate the different floor levels through which access can be obtained to the car when in registry therewith, a door being associated with each opening for closing it when the car is in some other position.

When the doors are arranged for independent manual operation they are frequently not closed when they should be because of carelessness or some other reason; this gives rise to accidents particularly when the upper door, as is often the case, is beneath a counter or in a generally similar location with its sill relatively close to the floor. Consequently some attempts have been made to provide means for automatically closing and opening the doors at the proper times but the mechanisms designed for accomplishing this purpose with which I am familiar are extremely complicated and therefore apt to get out of order, while their cost is often so great as to be prohibitive. I

It is therefore a principal object of my invention to provide automatic closure means for dumb waiter elevator hatchway openings and the like which are extremely simple in design and construction, inexpensive to install and which positively prevent the upper hatchway opening being left unguarded by its door save when the elevator car is in proximity to it.

Another object is to provide doors for hatchway openings located at different floor levels which are counter-weighted against each other and automatically operative in response to movement of the elevator car from one opening to the other to prevent access to the hatchway through either of the openings while the car is in registry with the other.

A further object is to provide doors of this character and interconnecting and operating mechanism therefor whereby the weight of one of the doors is utilized to actuate the other and bring it into registry with the adjacent opening as the elevator car moves away from it to thereby keep that opening closed until the car during its return thereto causes the doors to move in the opposite direction.

Other objects, purposes and advantages of the invention will hereinafter more fully appear or be understood from the following description of a preferred embodiment of it diagrammatically illustrated in the accompanying drawing in which Fig. 1 is a fragmentary front view of a typical dumb-Waiter elevator and hatchway including automatically operating doors in accordance with the invention;

Fig. 2 is a fragmentary side elevation thereof partly broken away into vertical section;

Fig. 3 is an enlarged perspective detail of one element of the mechanism shown in the preceding figures, and

Fig. 4 is a similarly enlarged perspective detail of another.

In the several figures, like characters are used to designate the same parts.

In the drawing, illustration of many parts of the elevator mechanism normally essential to its proper operation is omitted since these may be of any desired character adapted for the performance of their several functions and constitute no part of the present invention which is immediately concerned only with the hatchway opening doors and the operating mechanism therefor.

Thus Figs. 1 and 2 diagrammatically illustrate the general arrangement of a typical dumb waiter elevator of the character to which I have referred, including an elevator car I suspended from a cable 2 in a hatchway H and vertically slidable along suitable guides (not shown) between adjacent fioors 3 and 4. The upper floor 3 may for example be the first floor of a retail store with its hatchway opening 5 disposed beneath a counter or the like and therefore having its lower edge adjacent the floor level instead of raised substantially above it, while in the basement the lower floor 4 is aligned approximately 7 with the bottom of the hatchway and the lower hatchway opening 6 spaced above the floor at a sufiicient height to permit convenient access to it for loading or unloading the elevator car when it is in registry therewith.

It will be understood that manual or power driven car operating means (not shown) adapted for control from adjacent either the upper or the lower floor or from both, are provided for moving the car from one floor to the other, while counter-weighting means (not shown) are usually associated with the car to facilitate its travel with a minimum expenditure of energy.

hatchway. whenever the doors are moved from these nor- An upper door H] and a lower door ll respectively adapted to close the hatchway openings 5 and 6 are arranged to move vertically from closed to open position and vice versa on suitable guides associated with the hatchway structure, and the doors themselves, as well as the guides, may be of any convenient or desired specific character; thus the details of their construction require no extended description and are not illustrated, as they form 110 part of the invention. It is preferable, however, that one door be somewhat heavier than the other, and in the embodiment of the invention now being described the lower door H is the heavier.

The doors are interconnected at either side of the hatchway by means of chains l2 or other flexible tension members the ends of which are respectively attached to the upper .door l through the medium of suitable brackets I4 and to the lower door I I through the medium of other suitable brackets I5, these several brackets being shown as secured to the respective doors adjacent their side edges, Brackets l5, however, project into the hatchway farther than brackets I4 so that the chains l2 which pass over sheaves I6 mounted for rotation on suitable supports 1? adjacent the top of the hatchway run substantially vertically between the brackets and the sheaves. If desired, the sheaves may besecured to a common shaft (not shown) at the top of the hatchway for unitary rotation when either is turned by its chain but this is usually unnecessary particularly when both chains are actuated in unison but independently as in the illustrated construction, as the doors are then operated from a both sides at once and freedom of travel along their guides thereby insured.

Through this interconnection of the doors by the chains, movement of either door is equal in distance but opposite in direction to movement of the other, and as lower door I l is heavier than upper door l0, they normally occupy the positionsindicated in Figs. land 2, that is, the lower door is depressed below hatchway opening 6 while the upper door is raised to registry with hatch- .wayopening-5 to prevent access through it to the Moreover, it will be apparent that mal positions and then released, lower door H will cause the upper door to rise into registry with upper opening 5 as the lower door descends by gravity below lowerlopening 6.

For causing the doors to automatically leave these so-called normal positions when the elevator car is-moving upwardly into registry with the upper-opening, means are provided whereby at the-proper time the ,car assumes and'sustains part of the weight of the heavier door and thereby shifts the overbalanced relation between the doors, thus allowing the lighter one to move by gravity out of registry with opening 5 and raising the other into registry with opening 6; likewise, following reversal of its movement, the car releases the doors and thereby allows the force of gravity'to move them in the opposite direction to their normal positions.

The means to which reference has just been made preferably comprise a pair of substantially cylindrical metal blocks or abutment-s 20 havthe set screws at suitablepoints adjacent the upper floor level, together with actuating memblocks.

bers carried by the car and engageable with these These members include tubular sleeves 24 surrounding chains l2 and supported on brackets 25 attached to opposite sides of the car, the sleeves being of such inside diameter that the chains but not the blocks can pass freely through them. Thus when positioned in vertical alignment with the portions of the chains extending between lower door brackets l5 and sheaves It, the sleeves can move along the chains with a minimum of "friction as the car moves relatively to the chains, and as the inside diameter of the sleeves is appreciably less than the outside diameter of blocks 29, it will be apparent that as the car rises toward upper opening 5 the sleeves engage the blocks. As the latter are secured to the chains and cannot pass through the sleeves, further movement of the car and sleeves therefore carries the blocks 25 upward to lift those portions of the chains to which they are secured and in turn lower door ll, thereby allowing upper door Hi to descend by gravity from registry with upper hatchway opening 5. Consequently when the car has moved into registry with the latter the upper door has entirely cleared it and the lower door simultaneously has been raised to registry with lower opening 6 to prevent access to the hatchway therethrough until movement of the car is reversed. 7

Upon such reversal the greater weight of door Ii maintains blocks 20 in engagement with sleeves 24 until door It has been restored to registry with the upper opening and lower opening 8 correspondingly vacated by door ll. Thereafter further downward movement of the car has no eiiect upon the doors and the car is therefore acccesible through the lower opening after it aligns therewith, while the upper opening re mains protected by its door it.

It will thus be apparent that my invention provides simple and effective means'for automatically operating the hatchway doors of elevators of the class described in coordinated relation and in such manner that the energy supp-lied for raising the elevator car is partially employed to overcome the preponderance of the heavier door and thereby allow the doors to move rclativeiy to each otherin one direction while the force of gravity alone is ultilized to similarly movethem in .the other whereby the upper hatchway opening is closed at all times when the car is out of registry therewith and the lower openin g is closed when the car is at the upper one, It is therefore impossible for attendants on the lower floor to get their heads or' arms into the hatchway while the elevator is being loaded or unloaded at the upper floor and the chance of injury through having articles dropped down the hatchway past the car is thus-prevented; Moreover, the closing movement of the lower door serves as a signal to the operator at the lower floor that the car is approaching the upper one,

and thus enables him to readily determine when to deener'gize the car lifting mechanism.

While I have herein diagrammatically illustrated-and have described with considerable particularity one embodiment of the invention, it will be understood I do not desire or intend to limit or confine myself thereto in any way as changes and modifications in the form, construction and arrangement of the several parts as well as in their relationship to each other and in their respective specific functions will readily occur 'to those skilled in the art and may be .made'if desired without departing from the spirit and scope of the invention as defined in the appended claims.

Having thus described my invention, I claim and desire to protect by Letters Patent of the United States:

1. In combination with an elevator car movable between vertically spaced hatchway openings, a door adjacent and. vertically slidable into and out of registry with each opening, and means interconnecting the doors in mutually counterweighted relation operative to move each door relatively to its opening in correspondence with movement of the other door in the opposite direction relatively to its opening.

2. In combination with an elevator car movable between vertically spaced hatchway openings, a door adjacent and vertically slidable into and out of registry with each opening, and means interconnecting the doors in mutually counterweighted relation operative to move each door in correspondence with movement of the other door in the opposite direction, one of the doors being heavier than the other, whereby when released from registry with its opening it descends by gravity and simultaneously through the interconnecting means raises the other door relatively to its opening.

3. In combination with an elevator car movable between vertically spaced hatchway openings, a door adjacent and vertically slidable relatively to each opening, and means interconnecting the doors in mutually counterweighted relation in such manner that when either door is in registry with its opening the other is out of registry with its opening, said means being operative to move each door in correspondence with movement of the other door but in the opposite direction and one of the doors being heavier than the other whereby when released from registry with its opening it descends by gravity and simultaneously through the interconnecting means raises the other door to registry with its opening.

4. In an elevator of the class described including a car, a hatchway having spaced openings, and vertically movable doors for said openings, movable tension means extending from the top of the hatchway to and interconnecting both doors in overbalanced mutually counterweighted relation, and means carried by the car operative during its movement toward one opening to lift one of the doors to thereby: interrupt said overbalanced relation and allow the other door to move in the opposite direction.

5. In an elevator of the class described including a car, a hatchway having spaced openings and vertically movable doors for said openings, sheaves adjacent the upper part of the hatchway above both doors, flexible means passing over the sheaves and interconnecting the doors to normally maintain them in overbalanced mutually counterweighted relation, and means carried by the car operative during its movement adjacent one opening to sustain a part of the overbalancing load to thereby allow the doors to move in opposition to said load.

6. In an elevator of the class described including a car, a hatchway having spaced openings and vertically movable doors for said openings, one of the doors being heavier than the other, a sheave adjacent the top of the hatchway, tension means passing over the sheave and interconnecting the doors whereby the heavier door normally aliords support to the lighter one from the sheave through said tension means, an abutment secured to the tension means between the heavier door and the sheave, and means carried by the car engageable with the abutment during movement of the car toward one opening to impose on the car a part of the weight of the heavier door and thereby enable the doors to move in opposite directions.

7. In an elevator of the class described including a car, a hatchway having spaced openings and vertically movable doors for said openings, the door adjacent one opening being heavier than the other door, a mutually counterweighting connection between the doors whereby one door is normally maintained in registry with one opening and the other door is normally maintained out of registry with the other opening, and means carried by the car adapted during its upward movement to sustain part of the weight of the heavier door to thereby allow the doors to simultaneously shift from said normal positions and adapted to maintain the doors so shifted after the car is at rest in registry with the upper opening.

8. In combination with an elevator hatchway having vertically spaced openings and a car movable therein, a pair of doors respectively slidable over said openings, one of said doors being heavier than the other, means suspending the doors in mutually counterweighted relation with the heavier door normally maintaining the other in position to close its opening, and means carried by and operative after the car reaches a predetermined point in its upward travel to overcome the preponderance of the heavier door and enable the doors to move relatively to each other in opposite directions.

9. Elevator hatchway opening closure mechanism of the character described comprising a pair of vertically slidable doors respectively adjacent vertically spaced openings in the hatchway, sheaves disposed above the upper door, flexible tension means passing over the sheaves and interconnecting the doors, abutments fixed to the tension means adjacent the upper door, and means carried by the elevator car engageable with the abutments during its upward movement to thereby supplement the force of gravity acting on the upper door to move said door out of registry with the upper opening and the lower door into registry with the lower opening.

10. In combination with an elevator hatchway having vertically spaced openings and a car movable therein, a pair of doors respectively adapted to slide over said openings, flexible means suspending the doors in mutually counterweighted relation, the lower door being the heavier and tending to maintain the upper over its opening, means carried by the car cooperative with said flexible means when the car is travelling upward to overcome the preponderance of the lower door and thereby enable the upper door to descend from its opening while raising the lower door toward its opening.

NICHOLAS R. GUILBERT, JR.

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