The invention relates to an elevator interlocking mechanism, compnsmg a lift cage door having interlocking of the lift cage door, and a landing door at each landing having interlocking ofthe landing door, said doors being interlocked, when the hft cage is movmg, the interlocking ofthe lift cage door and the interlocking of a landing door may be released . when the lift cage is at rest at the respective landing of said landing door

Pnor art lifts have been provided with vanous locking mechanisms for preventing the lift cage door or the landing doors from being opened, when the lift cage is in motion or beyond a landing These pnor solutions of the above problems have always compnsed a more or less complex separate interlocking mechanism for the lift cage door and a separate interlocking mechanism for each landing , said interlocking mechanisms being independently operated In general vanous, fix cams, provided at each landing, have been used, which act on movable cam roll, associated with the lift or vice versa, by means of which the lnterlockmgs ofthe doors are released, so that the doors could be opened

The disadvantages of pnor art are that it requires a great precision in the manufacture and mounting ofthe vanous components involved Furthermore, the number of members ofthe pnor mechanisms is rather big, resulting in quite a high cost of assembly for these parts Further, the big number of precisionmade members implies that the locking mechanisms will become relatively sensitive to wear and dirt, leading to a non neglectable cost of maintenance

The object ofthe invention is to provide an interlocking mechanism ofthe kind indicated above and in the preamble of claim 1, which avoids those above discussed disadvantages, includes a significantly less total number of components than other mechanisms for this purpose, is wear resistant, and may be produced at a lower cost than before

This object is solved according to the invention in a mechanism of the kind defined in the preamble of claim 1 , which compnses the features, defined in the charactenzing part of claim 1 By these measures only one operating mechanism need be pro\ ided in the lift cage for operating the interlocking of he lift cage and all lnterlockmgs of the landings (of course, not all simultaneously) Thus, the number of members involved may significantly

be reduced in relation to pnor solutions

Further, the reduced requirements of accuracy in the positioning of the cams result m a quicker and simplified installation of the complete elevator system and in less costs as a consequence It should be noted that "door" in this connection includes all types of doors, that can be interlocked in a lift cage and at landings, single and double side hung doors, as well as vertical and honzontal push doors

Hereinafter a preferred embodiment ofthe invention will be explained more in detail It should be noted that for the sake of clanty only those details, which are necessary for the understanding of the pnnciples of invention, are explained and lllustated in the drawings In addition to this, the components involved are only schematically shown, thus, the drawings are not machine drawings

Figure 1 is a top view of the lift interlocking mechanism of the invention, mounted on a lift cage and at landings, respectively, several members being removed from these elements,

Figure 2 is a side view, seen from line II-II in fig 1 , ofthe components disposed on the lift roof, and

Figure 3 is a side view, seen from line III-III in fig 1, of the components provided at a landing for interlocking and for release ofthe interlocking of landing door provided at this landing

Pπncipally, the interlocking mechamsm of the invention compnses two main parts, one of which is attached to the lift cage 1, of which only a limited portion is shown, the other of which is fixed at a landing.

The lift cage part consists of a linear actuator 2, fixed to the lift cage by means of fittings 6 The actuator 2 compnses a cylinder and a piston rod 4, linearly displaceable in the cylinder In this case the cylinder has an electnc dnve motor, not shown, dnving an axially fix rotatable nut, which engages the at least partly as a screw formed piston rod 4 Of course, instead of an electrically dnven screw and nut mechanism, conventional pneumatic or hydraulic cylinders may be provided as actuators The motor is actuated by a sensing and control system, not shown, which will sense when the lift cage is at rest at

a landing The end ofthe piston rod 4 acts against a locking rod 8 extending generally in parallel to the piston rod 4 by means of a L-formed member 10, welded to the locking rod 8 (cf Fig 2), the locking rod 8 and the L-member being guided in a fix guide 16, designed in correspondence to these components The locking rod 8 is additionally guided at one end in a bush 22, attached to the lift cage, so that it is axially displaceable in parallel to the roof of the lift cage 1

The end 5 ofthe locking rod 8, situated at the the operating member 2 is tapered for facilitating the insertion thereof into a recess or an opening in a secunng plate 1 1 for the lift cage door Additionally, at a middle portion of the axial rod 8 a radial shoulder or collar 23 is provided, serving as a seat for a coil spnng 34, disposed on the axial lift locking rod 8, the opposite end of which engages the guide bush 22 or the wall, mto which the bush is inserted

On the end ofthe axial rod 8, protruding from the bush 22 radially protruding, towards the lift cage, an inclined angular arm 24 is provided, a cam roll being fixed, rotatable about an axis 28 This axis 28 extends generally normal to the locking rod 8 One leg 12 ofthe L-member extends vertically upwards from the locking rod 8, so that it will lie in the action line ofthe piston rod 4, the piston rod 4 thereby axially displacing the L-member 10 and thus the locking rod 8 against the action of the spnng 34 However, it should be noted that there is no fix connection between the piston rod 4 and the L member 10, the locking rod 10 being returned to its locking or start position bv the action of the spnng 34, only

The locking rod 8 conventionally cooperates with a secunng plate 1 1 , having an open recess or bore Said plate is in turn connected to a pivotable flap 21, which in a locking position prevents the lift door from being opened In the release position ofthe secunng plate 1 1 the flap may be pivoted about the indicated pivots 15a and 15b to release the lift door to permit the opening thereof The locking of the lift door does not constitute a part ofthe present invention, which may be earned out by any known manner and will of that reason not be further discussed hereinafter

The end of the locking rod 8 is of course adapted to the recess or opening of the secunng plate 1 1, so that it may be inserted without any difficulties into a locking position m case of interlocking, the guidance of the insertion being facilitated by the conicaily tapered end 5

The structure of the interlocking mechanism for the landing doors can best be seen in fig 3 Pnncipally, it operates in the same manner as the interlocking mechanism for the lift cage door Thus , for each landing it compnses a landing door locking rod 32, having a conicaily tapered end 39, which in case of interlocking will be insened into an appropnate recess or openmg in a secunng plate 38, which in a locking position, I e when the landing door locking rod 32 is inserted in the recess or opening of the secunng plate 38, prevents a flap for the locking ofthe landing door 48 from being displaced from the interlocking position

Landing door locking rod 32 is displaceable, generally in paralel to the lift door locking rod 8 and is guided at one end in a guide 37 fixedly attached to the landing and at the other end in a bush 33 fixedly connected to the landing A coil spnng, disposed between a fix shoulder 36 on the rod 32 and the bush 33, which serves as a return spnng for the rod 32 to its start or interlocking position

The end of the axial rod 32, situated in vincinity ofthe bush 33, is provided with a fix cam 30, connected to the end ofthe rod by a ngid arm 31, in such a manner that the cam 30 is positioned in the path of motion of the cam roll 26 of the lift cage locking rod 8 (in its interlocking position, when the lift cage moves upwardly or downwardly to the different landings) at a longer distance from the lift cage 1 than the cam roll 26

The interlocking mechanism operates as follows when the lift cage has stopped in a proper position at a landing, the position is sensed by sensing and control means, not shown, which then activates the actuator 2 to displace the piston rod 4, from its retracted locking position The latter will act on the L-member 10 so that this together with the lift door locking rod 8 will be displaced to the left in fig 2 After a certain distance of displacement the end 5 of the lift cage door locking rod has moved out from the recess or opening of the secunng plate 1 1, thereby releasing the interlocking of the lift cage door and compressing the spnng 20 In connection with the axial displacement of the locking rod 8, the cam roll 26 will be displaced, as well, and engage the cam 30 of the landing , which, while compressing the coil spnng 34, will be displaced to the left in fig 3, so that finally the locking rod of the landing disengages the secunng plate 38 Thereby, the lnterlockmgs ofthe lift cage door as well as of the door at the landing in question are released , said doors now being openable

Preferably, sensors are provided, which sense and deliver signals to the control

system of the lift about the interlocking condition, since it should not be possible to start the lift, if not the interlocking state has occurred Of this reason one end ofthe L-member 10 has a guide 14 similar to a ramp, which will be engaged by the sensing rolL 19 of a sensor 17 attached to the lift cage Similarly, a sensor 42 is provided for the interlocking ofthe landing door 48, the sensing roll 44 will engage a cam provided on the locking rod 32 for landing door

Thus, when the actuator has reached its end position, it will be indicated that the locking rods have reached their openmg positions, the power supply to the dnve means bemg interrupted In case of power failure the piston rod 4 will maintain its reached end position

If the lift cage should move to another landing, first the doors must be shut and interlocking occur, if power should be supplied to the dnve means When the doors are shut a start control means is actuated, acuator of the lnterlockmgs being activated in the retraction direction The compressed coil spnngs then will return the locking rods 8, 32, as the return movement ofthe piston rod 4 permits their returns, so that they will engage their respective secunng plates 11, 38 The sensors 17, 42 are arranged so that they will deliver signals to the control equipment ofthe lift, when this situation is present, the control equipment activating the dnve means so that the lift cage 1 moves Further it should be noted that the secunng plates 11, 38 also serve to prevent the locking rods from returning, if the actuator of any reason has returned and the respectn e door is open In addition to the above listed advantages of the interlocking mechanism, including amongst other things less sensivity to wear and positiomngs, the easy possibility of opening in emergency situations should be mentioned As should be realised, the locking rods are displaceable against the action ofthe spnngs 20 and 34, without need of activating the actuator 2

Further it almost goes by lself that the cam 30 ofthe landing only has a limited vertical extension and that it is positioned with a limited, allowable openmg area in the height direction between the lift cage 1 and the landing