Note: Descriptions are shown in the official language in which they were submitted.
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PIa!~TI~I(; COLLAPSIBLE CFIAIVE CAB
~IEL~ ~F THE 1NVENTtt~f~
The present invention generally relates to a pivoting collapsible operator's
cab for a crane, or the Pike. More particularly, it relates to a crane cab
having a variable geometry which can be expanded or refracted through
nesting of the bottom part under the top part of the cab as the top part
rotates about a pivot axis placed in a generally centre! location within the
cab.
BACIC~f~~UNCf ~F THE I~lilEf~Tl~I\l
Mobile material handfir~g machines are commor~pface in forestry and other
commercial industries. The operating contrals for these machines are
generally located in an area which provides maximum visibility of the
working area of the machine and are usually enclosed in a cab for the
operator's safety and comfort. However, due to the size of the handling
machine and the need to keep the overall size of the machine to a
minimum so as to permit travel over public roads or~ other transport means,
the space allocated for an operator's cab is firnited. These requirements
have created the need for collapsible cabs.
In prior art, coflapsibie cabs have followed two principal trends ire their
overall design. The first type of design uses a telescopic configuratian
whereby the bottom portion of the cab nests itself under the top portion
during a retraction of the cab structL~re. This design results in a
significant
reduction of the cab volume in its retracted state. i~owever, it also results
in a need for a complex set of mechanisms with multiple failure and contact
points in the case of a generally cubic cab design, as the mechanisms
must ensure that the four corners of the two retracting portions nest
properly one within another.
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The second general type of design which can reduce the effective height of
a cab involves a hinge mechanism. ~lnited States Patent No. 3,431,016
granted to Mundt-Petersen et al. discloses a method of reducing the profile
of a handling machine by means or' an operator's cab that pivots about a
horizontal hinge from a vertical position to an inclined position. This design
simplifies the retraction mechanism. ~ lowever, ~~ny volume savings in the
reduction of the effective height of the cab are compromised by a ia.rger
effective width of the cab in its inclined position.
Additionally, collapsible cab designs often result in cab access door
concepts which can only be opened or closed in two separate steps: first a
top portion of the door must be opened, Then the bottom portion.
Retraction mechanism designs often prevent the door portions of the cab
from becoming fully integrated and being opened or closed in a single step.
Thus, there is still presently a need for an improved cab design that is
collapsible during transporfi. The design must combine the benefits of a
nested and a hinged configuration in the control ~of the variable geomef,ry of
the cab, while avoiding the disadvantages inherent to these configurations.
Furthermore, there is a need for a collapsible cab door design which can
become fully integrated in its expanded configuration, to simplify the
opening or closing thereof.
S~JMIVIAi~Y ~F THE IN1~E~JTICJ
An object of the present invention is to propose: a crane cab that satisfies
the above mentioned needs.
The invention also has for its object to provide a pivoting collapsible cab
with a deployable str ucture which is sealed with the remaining cab
structure to inhibit the entrance of dust and other foreign debris in both
expanded cab and retracted cab positions.
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A further object is to provide a cab door design which fully integrates k~oth
top and bottom portions of the door with the cab in its expanded
configuration to permit ripening or closing of the door in a single step.
According to the present invention, that object is achieved with cab design
having a variable georr;etry which can be expanded or retracted through
nesting of the bottom portion under the top portion of the cab as the tap
portion rotates about a pivot axis placed in a generally centre! location
within the cab.
More particularly, 'the pr went invention provides a collapsible cab suitable
for use in mobile material handling machines. The cab comprises a top
portion, a bottom portion, a pivoting axis about which the top portion
rotates with respect to the bottom portion and an actuator to drive the top
portion between the expanded and retracted cab positions. The pivoting
axis is characterized in that it is located in a generally central location
within the cab. In this hinged design, the bottom portion nests itself under
the top portion in the retracted position. Consequently, the cab volume is
reduced significantly while benefiting from the simplicity of the rotation of
the top portion of the cab about a single rotation axis.
In accordance with a pr eferred aspect of the invention, the top and bottom
portions each comprise a respective access door. f n the expanded cab
position, a latching mechanism links the top door to the bottom door,
resulting iii a single access door unit which can be opened or closed
through actuation of a single opening mechanism located on the bottom
door.
The latching mechanism comprises a pivoting tine (orated on the top door
which receives a corresponding latch pin on the bottom door once the cab
is in its expanded configuration. Through interaction with the latch pir~, the
pivoting tine rotates in a manner such that a door release plate-shaped
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stopper on the bottom door becomes blocked ire between an edge of the
pivoting tine and an external part of the top door. The top door cannot be
opened independently from the bottom door with the door release stop
surface in this position.
A release mechanism is available to allow a separate opening of the top
door with respect to the bottom door. The door release stop surfac;e is
pivotally connected to a locking Lever which can be actuated by an operator
inside the cab. The operator can move the locking lever in a manner vu~hich
rotates the door stopper away from its position between the pivoting tine
and external part of the tap door. This rotation releases the constraint on
the top door which thereby becomes free to be opened separately from the
bottom door.
A non-restrictive description of a preferred embodiment of the invention will
now be given with reference to the appended drawings.
~f~IEF C~ES~R~PTI~I~ ~IF TWE L~ ll~IIVC~S
Figure 1 is a perspective view of a cab .according to a preferred
embodiment of the invention, in a cab retracted position.
Figure ~ is another perspective view of the cab of figure 1, in a cab
expanded position.
Figure ~ is a further perspective view of the cab of figure 1, in a cab
expanded position showing the cab access doors open.
Figure ~ is an exploded view of the door latching mechanism according to
a preferred embodimer7t of the invention, viewecl from a first angle.
Figure 5 is an additianal exploded view of the doer latching mechanism of
figure 4, viewed from another angle.
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Figures 6a to 6c show a perspective view of thcr interaction between the
door latching mechanism components of figure 1 as the cab reaches an
extended configuration.
Figures 7a to 7c show ~~ perspective view showing an actuation of the top
5 door release mechanism according to a preferred E3mbodiment of the
invention.
~ES~RIPTiOIV ~F FREFERRE~ ENfS~~INIENTS
Referring to any one of figures 1 to 3, a pivoting collapsible crane cab (10)
according to a first preferred embodiment of the invention comprises a top
portion {12) and a bottom portion (14). The cab (10) has a variable
geometry which can be expanded or retracted through nesting of the
bottom portion (14) under the top portion (12) of the cab (10) as the top
portion (12) rotates about a pivot axis (16) placed in a generally central
location within the volume of the cab (10).
Referring to figure 1, the bottom portion (14) is nested under the top portion
(12) in the retracted position. /fin actuator (17), as shown in figure 2, can
drive the cab (10) from the retracted configuration sho,Nn in figure 1 to the
expanded configuration shown in figure 2, whereby the top portion {12) has
been rotated about the pivot axis {10) away from its rested configur<~tion
over the bottom portion (14).
Figure 3 shows the cab {10) in the expanded configuration. The top
portion {12) and bottom portion (14) each comprises respectively a top
door (15) and a bottom door {20), which are matable to each other irr the
expanded configur ation to form a single door unit for access to the interior
of the cab (10).
The top door (15) and bottom door {20) are (irked ire the cab expanded
configuration in order to be opened or closed as a single door unit. The
bottom door (20} comprises a single opening and locking mechanism (40)
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used to open or lock the single door unit. The linkage between the top
door (18) and bottom door (20) is provided by a door latching mechanism
(22) located at the interFace between the top door (18) and the bottom door
(20), on the inner side thereof with respect to the cab (10).
Referring to either figure 4 or figure 5, the door latching mechanism (22)
comprises a pivoting tine (24) on the top door (18) which receives a
corresponding latch pin (26) on the bottom door (20}, when the cab (10) is
in its expanded configuration. The pivoting tine (24) comprises a plate-
shaped portion (23), two fork teeth (25) extending from the plate-shaped
portion (23) with an opening to receive the latch pin (2~), and a pivot point
(27) about which the pivoting tine (24) rotates during interaction between
the pivoting tine (24) and the latch pin (26).
Figures 6a to 6c Show the interaction between the door latching
mechanism (22) components as the top portion (12) reaches its end of
travel when it is pivoted from the retracted position to the expanded
position. The dour latching mechanism (22) components only come into
contact between each other in the final stages of the movement of the top
portion (12) to the expanded configuration. Through contact with the latch
pin (26}, the pivoting tine (24) is forced to rotate in a manner such that a
door release plate-shaped stopper (30} on the bottom door (20} becomes
blocked in between the pivoting tine (24) and an external part (34) of the
top door (18). The top door (18) cannot be opened independently from the
bottom door (14) with the door stopper (30) in this position.
Referring to figures 7a to 7c, the plate-shaped stopper (30) is pivetable
between a locked position, as in figure 7a, where it is blocked between the
pivoting tine (24) and the external part of the top door (18), and a released
position, as in figure ~7c, where it is away from its position between the
pivoting tine (24) and external part (34) of the tap door (12). The latching
mechanism (22) also comprises a biasing means for urging the stopper
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(30) to its Locked position, and a release mechanism (36) operable from
inside the cab (10) to bring the stopper (30) to its released position.
The release mechanism (30) is available to allow a separate opening of the
top door (12) with respect to the bottom door (14). Preferably. the release
mechanism (38) comprises a spring-loaded loc~kirzg fever (28) which is
operatively connected to the stopper (30) and can be actuated by an
operator inside the cab (10). As shown in figures ~a to 7c, the operator
can move the locking lever (28) in a manner which rotates the stopper (30)
to its released position. This rotation chang~as the orientation of the
stopper (30) which was acting as a Constraint on opening of the top door
(12). Without the constraint, the top door (12) becomes free to be opened
separately from the bottom door (14).
Although the present invention has been explained hereinabove by way of
a preferred embodiment thereof, it should be understood that the invention
is not limited to this precise embodiment and that various changes and
modifications may be effected therein without departing from the scope or
spirit of the invention.
