Note: Descriptions are shown in the official language in which they were submitted.
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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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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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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
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block carrying a bracket 13 is slideable, this block
i being the means whereby the lever is coupled to a link
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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
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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
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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
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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
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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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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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