Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
  • B66B5/00—Applications of checking, fault-correcting, or safety devices in elevators
  • B66B5/02—Applications of checking, fault-correcting, or safety devices in elevators responsive to abnormal operating conditions
  • B66B5/04—Applications of checking, fault-correcting, or safety devices in elevators responsive to abnormal operating conditions for detecting excessive speed
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
  • B66B5/00—Applications of checking, fault-correcting, or safety devices in elevators
  • B66B5/02—Applications of checking, fault-correcting, or safety devices in elevators responsive to abnormal operating conditions
  • B66B5/16—Braking or catch devices operating between cars, cages, or skips and fixed guide elements or surfaces in hoistway or well
  • B66B5/18—Braking or catch devices operating between cars, cages, or skips and fixed guide elements or surfaces in hoistway or well and applying frictional retarding forces

Definitions

• the present invention relates to a method and a device to ensure an actuation of a locking mechanism comprising several locking rods substantially radially displaceable in a rotary detail and which rods are both exposed to the gravitation and to centrifugal forces in rotation of the detail which centrifugal forces at a certain angular velocity of the detail will exceed the gravitation holding the locking mechanism in a retracted position.
• the present invention relates to a mechanism being used especially with a safety brake mechanism for elevators.
• SE-A-4.067 discloses a clutch mechanism between a rotary shaft and a machine component being mutually rotatable to the rotary shaft.
• This clutch mechanism comprises a cylindric body exposed both to the centrifugal forces and to the gravitation. At a certain revolutions per minute the cylindric body can be thrown out and engage the mutally turnable machine component. With this mechanism there is a risk that the cylindrical body will stuck or be delayed in its deplacement radially outwards making an inter ⁇ connection impossible, or will delay this interconnection.
• SE-A-338.836 discloses a mechanism controlling a displacement at elevators where a centrifugal activated mechanism is used too.
• a lever which, when exceeding a certain angular velocity, can be displaced to a position where it engage a braking lever.
• Said mechanism is too slow as it just has one releasing position for each revolution.
• Furthermore it has several joints and a Bowden mechanism which can be jammed and is not reliable enough to form part in a safety brake mechanism for elevators to be used in lifting disabled persons.
• SE-A-8605292-5 discloses a safety brake mechanism comprising a socket being coaxially mounted onto a chain sprocket.
• a diametrally displaceable plunger being influenced by the gravitation and det centrifugal forces. In exceeding a certain centrifugal force (angular velocity of the chain sprocket) the plunger will remain in its outfolded position and will struck against a stop preventing any further rotation of the chain sprocket.
• this safety brake mechanism has two or several possibli- ties to be released for each revolution of the chain sprocket, but the plunger portions being displaced by the centrifugal forces are mutually immovable and are of the one and same piece of material, thus there is a risk that the safety brake mechanism will not act properly when any of the plunger portions is jammed or stucked.
• the main object of the present invention is to obtain a method and a device in a centrifugal force activated locking mechanism to prevent jamming of mutually displaceable plunger means caused by corrosion, dirt, when covered with ice, etc., and make sure that an immediate actuation of the locking mechanism takes place after a certain angular velocity of a rotary component has been exceeded. This is of outmost importance in safety brake mechanism at elevators in which great gravitation forces are involved.
• the invention has a special application to relatively light personal elevators, e.g. such elevators used to lift a person carried by a wheel chair along stairs. It is hereby very important to keep the construction light and simple to minimize the gravitation forces acting onto the structure. To eliminate the risk of having the locking mechanism stuck in a not active position, the device is divided in several independable and mutally actuable details.
• Yet another object of the present invention is to obtain a technique being easy to apply to existing units and arrangements as the same time as an inspection and a control of the function of the locking mechanism shall be easily carried out.
• Another object of the present invention is to obtain a technique which besides rapid and safe activation of the locking mechanism at the same time is capable to activate a limit switch to switch off the current to the engine of the elevator.
• a break mechanism connected to the anvil can be activated and thus immediately perfore a braking action onto the elevator.
• Fig. la is diagrammatic side view of a rotary body, at the peri ⁇ phery of which two plunger elements are radially displaceable
• Fig. lb shows a plunger element in an extended position towards an anvil and activated by centrifugal forces
• Fig. 2 shows a plan view of the embodiment according to fig. lb
• Fig. 3 is a side view of a second embodiment of the invention wherin three plunger elements have been shown in a rotary body which is disposed excentrically in a recess and towards which lower periphery locking rods slide during the influence of the gravitation and centrifugal forces and where a stop is arranged at the upper portion of the recess, towards which any of the three locking rods can be brought to an engagement,
• Fig. 4 is a sideview of a third embodiment of the invention where a limited moveable breaking mechanism is arranged in connection to a stop actuated by any of the two radially displaceable plunger elements, and where
• Fig. 5 is a section along line 4 - 4 according to fig. 3.
• fig. 1 a diagrammatic side view of a locking mechanism including a rotary detail 1 with two diametrically opposed recesses is shown.
• locking rod means in the shape of two plunger elements 3 being radially displaceable.
• the one plunger element 3 has in fig. lb been shown during bearing on a stop 4.
• the plunger element 3 has a cylindrical section - see fig. 2 - but other sections are possible too.
• a further breaking mechanism can be activated in a way to be described in connection to the embodiment according to fig. 3 and 4.
• the locking rod means 3' comprises three plunger elements 3'a, 3'b and 3'c. Instedad of restricting the radial displacement of the plunger elements 3 by a stop acting onto the rotary detail 1', which is the case in the embodiment according to fig. 1, here the plunger element is sliding against an excentric surface in a body A' surrounding the rotary detail. When exceeding the angular velocity, which give rise to a centrifugal force exceeding the action of the gravitation, the plunger elements will come to a direct contact towards the stop 4'.
• rotary detail 1" is shown as a separate unit being in turn rigidly connectable to that part rotating as a consequense of the displacement of the elevator.
• the plunger element 3" is substantially the same as being shown ir connection to fig. 1.
• the stop 4" is located on a restricted turnable stopping device 5, 6 in an activated position being brought to bear on the flange surface 7, i.e. a stationary portion against which the lifting device can be stopped.
• a dis ⁇ connecting activator means 8 which in a relative displacement of the stopping device and the rotary detail 1', i.e. when releasing the locking mechanism, will disconnect the arm 9 of the switch 10.
• a spring 11 will hold the stopping device turned from engagement with the flange surface, whereby instead a wheel 15 will run against the flange surface 7.
• a bearing 13 between the rotary detail 1" and the stopp ⁇ ing device 5, 6 is shown.
• the guiding by spring pins 12a and 12b of the plunger elements 3"a and 3"b in the rotary detail 1" is also shown.
• the rotary detail 1" is secured by a bolt 14 at e.g. the axis of a sprocket gear (not shown).
• Several follower pins may be arranged to transmit torque between the gear (not shown) and the plunger element under influence of the centrifugal forces.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Braking Arrangements (AREA)
• Centrifugal Separators (AREA)
• Turning (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20389481

Family Applications (1)

Country Status (3)

Cited By (4)

Citations (3)

• 1993
  • 1993-04-04 SE SE9301129A patent/SE500997C2/sv unknown
• 1994
  • 1994-04-04 AU AU64406/94A patent/AU6440694A/en not_active Abandoned
  • 1994-04-04 WO PCT/SE1994/000301 patent/WO1994022756A1/en active Application Filing

Patent Citations (3)

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