CA1056413A

CA1056413A - Door actuating mechanisms

Info

Publication number: CA1056413A
Application number: CA267,473A
Authority: CA
Inventors: John C. Newson
Original assignee: Westinghouse Brake and Signal Co Ltd
Current assignee: Siemens Mobility Ltd
Priority date: 1975-12-20
Filing date: 1976-12-08
Publication date: 1979-06-12
Also published as: AU503389B2; AU2041676A; CH614488A5; BE849248A; GB1514570A; FR2335681A1; DE2657287A1; SE7614210L

Abstract

ABSTRACT

A door actuating mechanism is provided for a sliding door, the mechanism including an electric motor which drives an arm through a gear box the arm being coupled via a linkage to a point on the door and the linkage is such as to incorporate pivot means which is movable along a guideway, the pivot means being resiliently biassed towards one end of the guideway to permit movement along the guideway of the pivot means in the event of the door encountering an obstruction in its path towards the closed position.

Description

This invention relates to door actuating mechanisms.
In the Specification of United Kingdom Patent No. 1,357,998, there is described and claimed a door actuating mechanism including a drive shaft coupled to a track member which co-operates with a door operating lever at an action point to in operation cause angular movement of the lever away from an extreme position of the mechanism about a fulcrum of the lever and including urging means independent of driving force on the shaft and operable when the lever is in the vicinity of the extreme position to urge the crank towards a position corresponding to the said extreme position of the ~;
mechanism.
The above mechanism is mentioned by way of example only and in such a mechanism it may be desirable to provide means whereby when approach-ing the closed position of a door operated by the mechanism, the door can be manually deflected against and relative to the mechanism to permit release of a person or article which may otherwise become trapped by the door.
According to the present invention there is provided a door actuating mechanism including motor means mounted to produce angular motion of an operating lever which in operation is coupled to a door to be operated and wherein a guideway arrangement is provided which with said lever forms part of a l-inkage between the motor and said door, the linkage also including movable means which can execute movement along the guideway against the force of a spring in the event of the door encountering an obstruction in its path towards the closed position wherein at or near the closed position the guideway is disposed at an appreciable angle to the line of action of a pivoted link between the door and the lever, said angle reducing upon de-flection of said movable means along the guideway.

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~056413 Said guideway may comprise a slot in said lever and so disposed relative thereto that over a range of angular movement of the lever starting from a position corres-ponding to the closed position of the door a progressively increasing force is required against the linkage to result in movement along the guideway.
Said guideway may alternatively be provided in an adaptor member which is adapted to be bolted or otherwise attached to the lever to enable an existing mechanism to be convert~d to one provided with the benefits o~ the present invention.
Signalling means may be provided responsive to the said msans being away from a normal operating ` positlon in the guideway to signal the existence of such an obstruction, In order that the invention may be more clearly understood and readily carried into effect, the same will be further described by way of example with reference to the accompanying drawings of which, Fig. l illustrates in diagrammatical form a door actuating mechanism in accordance with one embodiment of the invention and Fig~ 2 illustrates a possible modification of Fig. 1.
Referring to Fig. l of the drawings, the door operating mechanism shown therein is original equipment and the lever is provided with a slot integral therewith.
A mounting plate is denoted by reference l normally intended for vertical mounting within the body of a vehicle and to the side of a door opening. The mounting . , .
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lOS6413 plate 1 carries an electric motor 2 which ls mounted with its axis in a vertical plane and coupled to a gearbox 3 having a horizontal output shaft 4 which carries a crank 5. The outer end of the crank is slideably ?
engaged within a slot 6 in the upper arm of a lever 7 by virtue of a drive pin 8 carried by the crank 5. The lever 7 i9 pivotally mounted to the base plate at the point 9 and has a lower arm 10 which is appreciably longer than the upper arm of the lever. The motor is reversible and according to the sense of energisation thereof, and in dependence upon operation of a suitable position switching which is not shown, the lever is operable from the position shown, (being that corresponding to the closed positiqn of a door connected thereto) to the ~ 15 alternative ~ dotted position 11 corresponding to ; the open position of the door, It will be appreciated moreover that by virtue of the fact that in the said two positions, the crank 5 is substantially at right angles to the upper arm of the lever, in the corres-i 20 ponding positions of the crank 5, the lever arm 10 is substantially locked in that position since there is no force component which can be transmitted from the arm 10 of the lever to cause rotational move-ment of the crank 5 and the gearbox shaft. The crank 5 may be provided with urging means for urging it into one or other of the extreme positions if required.
Referring to the lever arm 10, this is provided at its lower end with a guideway in the form of a further slot 12 within which movable means comprised by a slide , block carrying a bracket 13 is slideable, this block i being the means whereby the lever is coupled to a link .. I . ~

105~i413 14 to a pivot bracket 15 for connection to the rear edge of a slideable door. The arm carries a further fixed bracket 16 with a flange 17 corresponding to a similar fl~nge 18 of the bracket ~3. ~ rod 19 is connected to the flange 18 and is slideable in an aperture in the flange 17 of bracket 16. Resilient means, name~y a spring 20 is provided on the rod under compression between the said flanges to continuously urge the lower bracket 13 towards the lower extremity of the slot 12.
The arm 10 of the lever further carries a microswitch 21 contacts of which are operable to the open or closed position as may be desired in accordance with interlocking logic, by engagement with the upper end 22 of the rod 19 when the block carrying the bracket 13 i5 deflected upwardly along the slot 12 against the effect of spring 20.
In operation of the door operating mechanism, the switch 21 may be included in a reversing circuit for the motor 2 and may be included in a normally closed circuit in the position shown. The door i8 normally operable by appropriate sense of supply polarity to the motor 2 to be operated between the two extreme positions shown for the arm 10 of the .; lever. In the absence of any obstruction or attempt - to deflect the door from the intended position as : 25 dictated by the position of the lever 10, the block ~, carrying the bracket 13 remains at the lower end of the slot 12 but in the event of the mechanism encountering an obstruction in the doorway, the bracket 15 is deflected relative to the lever 10 in the direction of arrow 23 such that the linkage 14 and pivot bracket 15 , 105~i413 may take up a positlon indicated by the dotted lines at 14a and 15a the rod 19 being deflected relative to the lever to operate the microswitch 21 to an open circult condition in which it is effective to cause signalling means to cause a motor-reversing cycle to be initiated~ This motor-reversing cycle is such that the motor 2 drives the lever arm 10 in a direction towards the opening position of the door thereby relieving the obstruction of all force from the mechanism. After a full or at least partial re-opening of the door, the control logic is such as to revert to the original mode and a further door-closing attempt i~ made.
Not only does the overcoming of the spring 20 enable electrical sensing to be effected by virtue of signalling means such as the microswitch 21, but also the force which is applied to an obstructing body entrapped in the doorway by a closing door can be arranged to be suitably limited by appropriate selection _~.".... . . . .
of the rate of the spring 20. Furthermore, it will be observed that as the block carrying the bracket 13 ' . progressively moves along the slot 12 towards the - fulcrum 9 of the lever there is a progressively reducing force applied at the bracket 15, assuming that the increase of force exerted by the spring 20 under progressive compression over movement along the slot 12 is not so appreciable as to counteract the effect of the change of angle of the link 14. Such may be a desirable.
characteristic in a door operator where the safety of passengers is of the utmost importance.
By suitable selection of the geometry of the variable triangle of forces which exists at the points of action of the lever, different requirements having regard to push back and obstruction detection may be achieved. For example, push-back may be possible soon after the door begins to close and at a point when the guideway slot of Figure l has taken up a suf-ficiently obtuse angle to the link 14. This will require a relatively high push-back force initially but decreasing towards a relatively low value at the point of closing.
In an alternative arrangement the guideway may be formed in a plate as a replacement for the link 14 of Figure l and as illustrated diagrammatically in Figure 2. If the direction of the guideway 31 in the plate 30 is such as shown, it may be appreciated that similar characteristics to Figure l may be obtained having regard to the magnitude of the force required to deflect the spring at different positions of the lever 7 and therefore of plate 30. The signalling means may again comprise a microswitch such as 32 positioned in the path of the slideable pivot bracket 33.
Again, whilst the mechanisms described are provided l 20 with resilient means in the form of a spring, such resilient means may not always be necessary, depending upon the nature .~ of the triangle of forces which is used in the particular ~ application.

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:~ - 7 -to the magnitude of the force required to deflect the spring at different positions of the lever 7 and therefore of plate 30. The signalling means may again comprise a microswitch such as 32 positioned ln the path of the slideable pivot bracket 33.
Again, whilst the mechanisms described are provided with resilient means in the form of a spring, such resilient means may not always be necessary, depending upon the nature of the triangle of forces which is used in the particular application.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A door actuating mechanism including motor means mounted to produce angular motion of an operating lever which in operation is coupled to a door to be operated and wherein a guideway arrangement is provided which with said lever forms part of a linkage between the motor and said door, the link-age also including movable means which can execute movement along the guide-way against the force of a spring in the event of the door encountering an obstruction in its path towards the closed position wherein at or near the closed position the guideway is disposed at an appreciable angle to the line of action of a pivotted link between the door and the lever, said angle reducing upon deflection of said movable means along the guideway.

2. A door actuating mechanism as claimed in claim 1, wherein said guideway i8 at an angle to the directlon of action of the driving force between the lever and the door such that in the vicinity of the closed position of the door a smaller force is required against the door to produce such movement along the guideway than is required in further positions of the door.

3. A door actuating mechanism as claimed in claim 1 wherein said guideway is carried by the link between the lever and of the door and so disposed relative to the lever that over a range of angular movements of the lever starting from a position corresponding to the closed position of the door, a progressively increasing force is required against the linkage to result in a said movement along the guideway.

4. A door actuating mechanism as claimed in claim 3 the guideway comprising a slot in the lever or the link as the case may be.

5. A door actuating mechanism as claimed in claim 1, 2 or 3 wherein signalling means is provided responsive to a said movement to signal the existence of an obstruction.

6. A door actuating mechanism as claimed in claim 1, 2 or 3 wherein signalling means is provided responsive to a said movement to signal the existence of an obstruction said signalling means comprising a microswitch.

7. A door actuating mechanism as claimed in claim 1 or claim 2 wherein the guideway is formed in a member attached to the lever.

8. A mechanism as claimed in claim 1, 2 or 3, the movable means being resiliently biassed towards one end of the guideway.