Information
-
Patent Grant
-
6591946
-
Patent Number
6,591,946
-
Date Filed
Thursday, October 11, 200122 years ago
-
Date Issued
Tuesday, July 15, 200321 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Ellis; Christopher P.
- Tran; Thuy V.
Agents
- MacMillan, Sobanski & Todd, LLC
-
CPC
-
US Classifications
Field of Search
US
- 187 313
- 187 319
- 187 330
- 187 331
- 187 335
- 049 116
- 049 120
-
International Classifications
-
Abstract
A door locking system for retrofit installation on an automatic sliding two-panel door of an elevator car prohibits opening and closing of the door from the interior of the car when between two floors. The door locking system includes a hook retainer mounted on one side of the door opening. A locking pawl is mounted to a panel of the door on the opposite side of the opening for selectably engaging the hook retainer. A cable is coupled to a drive mechanism and to the locking pawl for disengaging the locking pawl from the hook retainer when at a floor stop. A flexible cable housing slidably retains the cable and defines a path length between the drive mechanism and the locking pawl. A path length adjuster mechanism is connected between two sections of the cable housing for manually adjusting the path length. A hold-down is mounted to the door to retain the cable housing in close proximity to the door while permitting movement parallel with the door in response to adjustment of the path length.
Description
BACKGROUND OF THE INVENTION
The present invention relates in general to elevator doors, and, more specifically, to an adjustable control cable for a door restrictor.
Automatic door systems on elevators must meet a requirement that elevator passengers be unable to open the car door from inside when the elevator car is beyond the door opening zone of a floor. Since regulations associated with this requirement are not very old, there remain very many elevator installations currently without a mechanism to prevent such opening. The door systems of such elevator installations must now be adapted to the present regulations, presenting the problem of updating nonconforming door systems with the smallest possible intrusion into the existing construction while minimizing additional parts and cost.
One solution is shown in U.S. Pat. No. 5,377,785 which is incorporated herein by reference. This patent shows a door locking system for retrofit installation on an automatic sliding door of an elevator car. At floor stops, the car door is coupled via cams and couplings with the hoistway door and is opened and closed together therewith. The locking system prohibits opening of the elevator door from the inside of the car when the car is between two floors (i.e., outside the door opening zone of a floor) by means of a rocker mechanism affixed to a fixed or movable cam of a clutch and coupling mechanism of the door. The rocker mechanism is tilted by coupler brackets of the hoistway door during normal operation of the door within the door opening zone. A cable wire connected between the rocker mechanism and a locking pawl disengages the locking pawl from a hook retainer to mechanically free the door for opening. The rocker mechanism is not actuatable outside of the door opening zone. The locking pawl is kept in a mechanically interlocked position by a compression spring when the rocker mechanism is not actuated, thereby preventing the door from opening.
The cable wire passes through a sheath or housing which creates a certain path length between the rocker mechanism and the locking pawl. For reliability of the locking system, cable stresses need to be kept low. Due to the arrangement of the cable wire, sheath, and locking pawl, actuation of the locking pawl causes the cable wire to bend. A single door locking system often goes through as many as one million locking/unlocking cycles in one year. The repeated sharp bending of the cable wire at a pinch point can lead to premature failure of the cable wire. Cable failure could mean that a door could stay locked even with the elevator car in the door opening zone. Therefore, kinking or potential pinching of the cable wire anywhere between the securing points at its ends should be avoided. Besides setting a path length and constraining the cable wire, the housing protects the cable wire from damage or kinking.
A retainer retains one end of the cable wire at the rocker mechanism. The locking pawl includes an adjusting bolt extending from one end of the pawl arm which retains an eye ring at the other end of the cable wire. Accurate actuation of the pawl mechanism depends on accurate control of the path length determined by the length of the sheath and the actual length of cable wire between the rocker mechanism and the locking pawl. The adjusting bolt on the locking pawl can be retracted or extended to change the effective length of the pawl arm and consequently the leverage of the locking pawl. However, the adjustment has little effect on the effective length of the cable wire. Therefore, variations in individual dimensions or changes (e.g., stretching) over time cannot be well compensated.
SUMMARY OF THE INVENTION
The present invention has the advantage of making fine adjustments in the disengagement of the locking pawl with a small number of inexpensive parts and reducing stress to the cable.
One aspect of the invention provides a door locking system for retrofit installation on an automatic sliding two-panel door of an elevator car which, at floor stops, is coupled with a hoistway door and is opened and closed together therewith. The locking system prohibits opening and closing of the door from the interior of the car when between two floors, that is, beyond a door opening zone of a floor. A locking pawl is mounted to a panel of the door. A hook retainer is mounted to be adjacent to the locking pawl when the door is closed so that the locking pawl is selectably engaged with the hook retainer. A drive mechanism has an unactivated position when the elevator car is between two floors and is movable to an activated position in response to the elevator car being located in the door opening zone. A cable coupled to the drive mechanism and to the locking pawl for disengaging the locking pawl from the hook retainer when the drive mechanism moves from the unactivated position to the activated position. A flexible cable housing slidably retains the cable and defines a path length between the drive mechanism and the locking pawl. A path length adjuster mechanism is connected between two sections of the cable housing for manually adjusting the path length. A hold-down is mounted to the door to retain the cable housing in close proximity to the door while permitting movement parallel with the door in response to adjustment of the path length.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a front view of an automatic elevator car door with a retrofit door lock system of the present invention;
FIG. 2
is a front view of an adjuster mechanism of the present invention;
FIG. 3
is a side view of the adjuster mechanism of
FIG. 2
;
FIG. 4
is a front view of a hold-down bracket for the cable housing of the present invention;
FIG. 5
is a side view of the hold-down bracket of
FIG. 4
;
FIG. 6
is a front view of a locking pawl of the present invention; and
FIG. 7
is an exploded perspective view of an alternative embodiment of the locking pawl.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1
shows a centrally opening elevator sliding door with a left door leaf or half
10
and a right door leaf or half
11
. Both door halves
10
and
11
are hung or suspended with rollers
12
which travel on a rail
13
and are opened and closed via a non-illustrated door drive system. Mounted on the left door half or leaf is the clutch and coupling system which is basically comprised of a fixed cam
8
, a movable cam
9
and a cam actuator
14
. The door locking mechanism installed on this automatic door includes a hook retainer
15
attached at the upper left of the right door half
11
, a locking pawl
16
attached at the upper right of the left door half
10
and shown in a locking position, a drawing wire sheath or cable housing
17
which is attached to the left door half
10
with clips or shackles
18
, a drawing wire or cable
20
movable within housing
17
and a whip, balance or rocker mechanism
21
which is mounted on movable cam
9
and which activates cable
20
. Rocker mechanism
21
includes an inclined surface or facet
22
on both its upper and lower ends.
Although a center-opening two-panel door is shown, the present invention can also be used with side-opening single-panel doors by mounting the hook retainer at a fixed location on the elevator cab.
The present invention achieves an ability to make fine adjustments in the displacement of locking pawl
16
during activation by means of a path length adjuster mechanism
23
and a hold-down bracket
24
. These components achieve a variable path length while avoiding additional sources of stress for cable
20
. In addition, an improved configuration of locking pawl
16
further reduces stress on cable
20
.
Referring to
FIGS. 2 and 3
, cable housing
17
is separated into two sections
25
and
26
and path length adjuster mechanism
23
is inserted between them. A U-bracket
27
has a cylindrically-shaped housing guide
28
on one leg of bracket
27
for fixedly retaining section
25
of cable housing
17
. The leg has a hole (not shown) big enough for cable
20
to pass through. At the opposite leg of bracket
27
, a threaded passage or nut
32
is fixedly mounted (e.g., welded) to receive a threaded barrel
30
. An adjusting head
31
at one end of threaded barrel
30
receives housing section
26
. Barrel
30
has a longitudinal bore through which cable
20
passes. Preferably, bracket
27
is mounted to door
10
.
The overall path length between the driving end of cable
20
at the rocker mechanism (or equivalently any other driving mechanism such as a cam driven lever or plunger) and the driven end of cable
20
at locking pawl
16
includes the length of housing sections
25
and
26
and the distance between them (which is occupied by path length adjuster mechanism
23
). The length of path length adjuster mechanism
23
includes a fixed length of bracket
27
and a variable distance D between bracket
27
and the abutment of housing section
26
with adjusting head
31
. Preferably, adjusting hear
31
includes a recess
37
where housing section
26
abuts with adjusting head
31
.
Adjusting head
31
has a faceted outer surface (e.g., for grasping by a wrench) to facilitate turning of threaded barrel
30
to slowly increase or decrease length D depending upon the direction in which threaded barrel
30
is turned. Recess
37
loosely holds housing section
26
so that threaded barrel
30
can turn freely. Since other portions of the cable path are fixed, changes in length D cause an inverse change in the length of free cable between the open end of housing section
25
and locking pawl
16
. Thus, the engaged/disengaged positioning of locking pawl
16
can be calibrated during either installation or maintenance by manipulating adjusting head
31
.
Since the path length between the driving end of cable
20
and bracket
27
is variable, housing section
26
must have at least a portion that can move or shift to accommodate changes in path length. Therefore, the lower portion of the housing loop is loosely retained by hold-down bracket
24
as shown in
FIGS. 4 and 5
so that housing section
26
can shift vertically in a plane parallel with the door, but it cannot move perpendicularly to the door and consequently interfere with objects in the hoistway.
Bracket
24
includes flat mounting sections
33
joined to door
10
by screws
34
. A pair of transverse sections
35
are connected by a vertical section
36
and have a length just slightly greater than the outside diameter of housing section
26
so that the housing can freely move in a vertical direction. Bracket
24
is positioned on door
10
to provide a range of upward and downward movement corresponding to the adjustment range of threaded barrel
30
. When adjusting head
31
is turned for increasing insertion into bracket
27
(e.g., clockwise), then cable housing section
26
shifts upward as indicated by arrow A in
FIG. 4
, reducing the path length and allowing the hook on one end of locking pawl
16
to move farther into hook retainer
15
. On the other hand, when threaded barrel
30
is retracted from bracket
27
, then path length is increased, housing section moves downward in the direction of arrow B, and the hook on locking pawl
16
moves away from hook retainer
15
.
Locking pawl
16
is shown in greater detail in FIG.
6
and includes a lever arm
40
and a base
41
mounted to door
10
by bolts or screws
50
. Lever arm
40
has a locking hook
42
at one distal end and has a pivot hole
43
receiving a pivot pin
44
mounted on base
41
. Lever arm
40
can be retained on pivot pin
44
by staking or by a screw and rotating washer, for example.
Cable
20
exits housing section
25
and is routed over a curved bearing surface
45
formed as a ridge protruding from lever arm
40
. Cable
20
is secured to lever arm
40
by a locking washer
46
and screw
47
beyond the end of bearing surface
45
to ensure that cable
20
is supported against bearing surface
45
at all times.
In a preferred embodiment, bearing surface
45
and the end termination of cable housing section
25
are mounted such that cable
20
exits housing
25
in direct alignment with bearing surface
45
. Furthermore, the curvature of bearing surface
45
is designed to keep cable
20
coming straight out of housing section
25
at all rotational positions of lever arm
40
. In other words, as bearing surface
45
rotates, a tangent to the curved surface at the point where cable
20
lifts off of curved surface
45
is always vertical and stays substantially aligned with the termination of housing section
25
. For example, if the center of curvature coincides with the axis of rotation (i.e., pivot pin
44
), then the curvature would be an arc of a circle. For a more compact design, the center of curvature can be moved away from pivot pin
44
resulting in a more elliptical curvature of bearing surface
45
as shown in FIG.
6
. In either case, stress in cable
20
is greatly reduced and reliability is increased since there is no kinking of cable
20
at any point.
Lever arm
40
is biased against the action of cable
20
and into a position where locking hook is pulled downward into the hook retainer by an extension spring
51
. One end of spring
51
is captured in a hole
52
in lever arm
40
and the other end of spring
51
grasps a peg
53
projecting from base
41
. A torsion spring or other placements of an extension spring or a compression spring could also be used.
FIG. 7
shows an alternative embodiment of locking pawl
16
. The bearing surface is provide by a guide plate
55
which is mounted between lever arm
40
and a retainer plate
56
using a pair of bolts
57
. Retainer plate
56
extends axially beyond guide plate
55
to keep cable
20
from slipping off of the bearing surface.
In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.
Claims
- 1. A door locking system for retrofit installation on an automatic sliding two-panel door of an elevator car which, at floor stops, is coupled with a hoistway door and is opened and closed together therewith, wherein said locking system prohibits opening and closing of said door from the interior of said car when between two floors, that is, beyond a door opening zone of a floor, said door locking system including:a locking pawl mounted to one panel of said door; a hook retainer mounted to be adjacent to said locking pawl when said door is closed, said locking pawl being selectably engaged with said hook retainer; a drive mechanism having an unactivated position when said elevator car is between two floors and movable to an activated position in response to said elevator car being located in said door opening zone; a cable coupled to said drive mechanism and to said locking pawl for disengaging said locking pawl from said hook retainer when said drive mechanism moves from said unactivated position to said activated position; a flexible cable housing slidably retaining said cable and defining a path length between said drive mechanism and said locking pawl; a path length adjuster mechanism connected between two sections of said cable housing for manually adjusting said path length; and a hold-down mounted to said door to retain said cable housing in close proximity to said door while permitting movement parallel with said door in response to adjustment of said path length.
- 2. The door locking system of claim 1 wherein said locking pawl is comprised of:a pivot pin; a locking hook; a curved bearing surface for receiving said cable; a cable fastener for retaining an end of said cable such that said cable bears against said curved bearing surface; and a biaser for urging said locking hook into engagement with said hook retainer.
- 3. The door locking system of claim 2 wherein said cable bears against said curved bearing surface at all times.
- 4. The door locking system of claim 2 wherein said cable housing has a termination substantially directly aligned with a tangent at a near end of said curved bearing surface.
- 5. The door locking system of claim 4 wherein said curved bearing surface is shaped such that as said locking pawl moves between being engaged and disengaged, a tangent to said curved bearing surface at each point where said cable lifts off of said curved bearing surface during said movement stays substantially aligned with said termination of said cable housing.
- 6. The door locking system of claim 2 wherein said biaser is comprised of a spring.
- 7. The door locking system of claim 1 wherein said hold-down is comprised of a bracket.
- 8. The door locking system of claim 1 wherein said hold-down is mounted over said cable housing between said drive mechanism and said path length adjuster mechanism.
- 9. The door locking system of claim 1 wherein said path length adjuster mechanism is comprised of:a threaded barrel having an interior bore receiving said cable and having a collar receiving one of said sections of said cable housing; and an adjustment bracket receiving the other one of said sections of said cable housing at one end and receiving said threaded barrel in a threaded passage at an opposite end.
- 10. A door locking system for retrofit installation on an automatic sliding two-panel door of an elevator car which, at floor stops, is coupled with a hoistway door and is opened and closed together therewith, wherein said locking system prohibits opening and closing of said door from the interior of said car when between two floors, that is, beyond a door opening zone of a floor, said door locking system including:a locking pawl mounted to one panel of said door; a hook retainer mounted to be adjacent to said locking pawl when said door is closed, said locking pawl being selectably engaged with said hook retainer; a drive mechanism having an unactivated position when said elevator car is between two floors and movable to an activated position in response to said elevator car being located in said door opening zone; a cable coupled to said drive mechanism and to said locking pawl for disengaging said locking pawl from said hook retainer when said drive mechanism moves from said unactivated position to said activated position; a flexible cable housing slidably retaining said cable and defining a path length between said drive mechanism and said locking pawl; and wherein said locking pawl is comprised of: a pivot pin; a locking hook; a curved bearing surface for receiving said cable; a cable fastener for retaining an end of said cable such that said cable bears against said curved bearing surface; and a biaser for urging said locking hook into engagement with said hook retainer.
US Referenced Citations (8)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0 634 353 |
Jan 1985 |
EP |