The present invention relates generally to an operator cab used for a construction machine and particularly to an operator cab for a construction machine which has an entrance door.
Construction equipment such as a hydraulic mini-shovel comprises an operator cab and a construction machine, which are provided on a vehicle body, so that they are easily turned around for performing construction work. While work is being performed, the door of the operator cab, through which an operator gets into or out of the cab, is usually closed, but it is sometimes kept open.
In a case where the door slides back and forth along a rail, a handle used to open or close the door is provided on a side toward which the door closes (this side is referred to as “front side”) while a lock to maintain the opened and closed conditions of the door is provided on a side toward which the door opens (this side is referred to as “rear side”). To support this design, at the central part of the door, a mechanism is provided to connect the handle and the lock and to engage or disengage the lock to or from a striker. Because of such a complicated design of the door, there are following problems. The door is thick and heavy, so the manufacturing cost of the door is relatively high. Also, because of the mechanism placed at the central part of the door, a window is not available for outside view on the door. Furthermore, as for operability in opening and shutting the door, rollers and a slide rail constituting a slide mechanism present rough movements for the opening and closing of the door. The door just before its complete closure rubs the cab on the front side and moves along the lateral face of the cab on the rear side. This makes not only the feel of the door operation awkward but also makes the seal of the door malfunction, causing leakage.
It is an object of the present invention to provide an operator cab for a construction machine which cab has a door to be opened and closed through a link mechanism that connects pivotally the front side of the door to a cab box and through a slide mechanism that connects the rear side of the door to the cab box.
An operator cab according to the present invention is provided for a construction machine, and the operator cab comprises a cab box, a door, a link member and a slide member. The cab box has an internal cab room and an entrance into the cab room, and the door is attached at the entrance such that the entrance is closed when the door is moved forward, and it is opened when the door is moved rearward. One end of the link member is connected pivotally to the cab box while the other end is connected pivotally to the front end of the door, the link member being capable of freely swinging horizontally. On the other hand, the slide member is connected pivotally to the rear end of the door so as to freely swing horizontally, and the slide member slides in the back-and-forth direction along a slide rail, which is provided externally on the cab box, the slide rail extending in the back-and-forth direction.
As a construction machine to which the present invention relates, there is such a construction machine as a hydraulic mini-shovel 50, whose vehicle body supports an operator cab rotatably as mentioned in the following embodiment.
It is preferable that the link member comprise an upper link member and a lower link member, which are connected pivotally to the upper front end and the lower front end of the door, respectively, the upper and lower link members being capable of freely swinging horizontally. It is also preferable that the lower link member be provided below the floor of the cab box, so that the lower link member never intrudes the cab room. Furthermore, it is preferable that the slide rail be provided approximately at the vertical center of the external surface of the cab box in rear of the entrance, the slide rail extending in the back-and-forth direction.
Moreover, it is preferable that part of the side of the cab box including the door in its closed condition be flat and extend linearly in the back-and-forth direction in a top view.
By constructing the operator cab for a construction machine in a way as described above according to the present invention, a good feel of the door operation, i.e., the opening and closing of the door, is achieved because the movement of the door just before the complete closure is directed inward in a similar way as a prior-art hinged door. This inward movement of the door at the final moment of the closing pushes a seal member, which is provided to seal the door to the cab box, head-on, so the seal member achieves a high endurance and watertightness. Furthermore, the present invention provides an improved safety because the door never drops off from the cab box even if the slide member comes out of the slide rail accidentally, because the front part of the door is supported by the link members.
Also, the link members, which comprise upper and lower link members at the upper and lower ends, respectively, of the door, contribute to the improvement in the feel of the door operation because this arrangement of the link members eliminates any looseness in the support of the front part of the door. Furthermore, as the lower link member is arranged never to enter the cab room, the safety and convenience of the operator getting into and out of the operator cab are not jeopardized. Moreover, the positioning of the slide rail approximately at the vertical center facilitates the smoothness of the door operation.
According to the present invention, the part of the side of the cab box that includes the door extends linearly in a top view. This design enables to provide relatively large widths for the front and the rear of the operator cab and thereby secures a wider space especially at the feet of the operator in the cab room.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only and thus are not limitative of the present invention.
Now, preferred embodiments according to the present invention are described in reference to the drawings. Before an operator cab according to the present invention is described, a hydraulic mini-shovel 50 as an example of construction machine that incorporates an operator cab is described in reference to
Now, the construction of a door 2 as a first embodiment, which is attached to the operator cab 53, is described in reference to
As mentioned above, the upper and lower link members 3 and 4, which constitute the link mechanism 20, one ends (fixed ends 3a and 4a) are connected pivotally to the cab box 1 so as to swing freely while the other ends (3b and 4b) are connected pivotally to the upper and lower front ends of the door 2 so as to swing freely as shown in
As mentioned above, the slide mechanism 30 comprises a slide rail 5, which extends in the back-and-forth direction behind the entrance 15 and approximately at the vertical center of the entrance 15 outside the cab box 1, and a slide member 6, which is attached to the door 2 and slides along the slide rail 5, as shown in
In a condition where the slide member 6 is attached to slide along the slide rail 5, the guide rollers 6c, which are positioned in the rail groove 5a of the slide rail 5, roll and slide along the rail groove 5a, and the center roller 6d rolls and slides along the lower side 5b of the groove of the slide rail 5. Because the outward end of the upper side of the slide rail 5 is bent downward, defining the rail groove 5a, as mentioned above, the guide rollers 6c never go out of the rail groove 5a, so they securely guide the sliding of the slide member 6 along the rail groove 5a. Also, because the rocker 6b of the slide member 6 can swing with respect to the bumper 6a, the door 2 swiveling the rocker 6b can slide even though the slide rail 5 is bent as shown in
At the front part of the door 2, a closed door lock 7 is provided to keep the closed condition of the door 2, and the closed door lock 7 is engaged with a closed door striker 8, which is provided at the part of the cab box 1 facing the closed door 2 (at the front of the entrance 15) as shown in
The cab box 1 is provided with an opened door stopper 11, which fits with the bumper 6a at the rear part of the door 2 when the door is opened, keeping the opened condition of the door, and with a closed door stopper 12, which fits with the bumper 6a at the rear part of the door 2 when the door is closed, keeping the closed condition of the door. The opened door stopper 11 comprises a bracket 11b, which is mounted in rear of the slide rail 5, and a protruding part 11a, which is mounted on the bracket 11b and extends (in the back-and-forth direction) approximately in parallel with the slide rail 5 as shown in
In a case of a prior-art door whose front and rear slide, a tab tail (a part of a mechanism in which a convex is inserted into a concave for fixation) is provided at the front part of the door for fixing the opened door, and a mating part is provided on (a center pillar part of) the cab box. In this case, because clumsy brackets for mounting the tab tail are required at the front upper and lower ends of the door, the brackets obstruct the view and impair the safety. Moreover, because stoppers are mounted on the rear external side of the cab box, protruding outward, this design is not good in appearance and safety. On the other hand, in the embodiment according to the present invention, only the opened door stopper 11, which is for fixing the rear part of the door, is provided externally along the rear part of the slide rail 5. The closed door stopper 12, the bumper 6a and the like are provided inside the door 2, so they are not visible from the outside. As a result, the operator cab according to the present invention provides improvements in appearance (external design) and safety and in the range of vision.
At the front part of the door 2, a handle 13 is provided for opening and closing the door 2 from the inside and outside of the cab box 1. The handle 13 is used to release the engagement between the closed door lock 7 and the closed door striker 8 for opening the door 2 or to release the engagement between the opened door lock 9 and the opened door striker 10 for closing the door 2. Because the mechanism used for opening and closing the door 2 is provided integrally at the front part of the door 2 (approximately at the vertical center in
As shown in
As shown in
In this embodiment, as the door 2 is supported by the link mechanism 20, the door 2, which is retained by the link mechanism 20, will not come off from the cab box 1 even if the slide member 6 comes out of the slide rail 5. In this way, the present invention provides an improved safety.
There is a clearance between the slide rail 5 and the guide rollers 6c and center roller 6d of slide member 6 for these rollers to rotate, and the rocker 6b, which retains the guide rollers 6c and the center roller 6d, swings with respect to the bumper 6a. The clearance and the swing cause the rear part of the door 2 to be a little shaky during the opening and closing. However, the door 2 is secured without looseness when the opened door stopper 11 and the closed door stopper 12 engage with the bumper 6a of the slide member 6 to fix the door 2, respectively when the door 2 is opened and when it is closed as mentioned above. Furthermore, because the fitting recesses 6e and 6f that fit with the stoppers 11 and 12 for fixing the door 2 are provided not as separate parts but as part of the bumper 6a of the slide member 6, the side of the cab box 1 is smooth without protrusions that may impair the external look of the operator cab.
Now, the movement of the door 2, which is constructed as described above, is described in reference to
As shown in
As for the shape of the operator cab 53 (cab box 1), the part 1a of the side of the cab box 1 where the door 2 is attached on the cab box 1 extends linearly in the back-and-forth direction in a plan view as shown in
In a case where the door 2 is made larger and heavier, the upper and lower link members 3 and 4, which constitute the link mechanism 20, are strengthened with rollers 16, which are provided to carry the weight of the door 2 as shown in
In the above described embodiment, the bumper 6a of the slide member 6 is provided with fitting recesses 6e and 6f, with which the protruding parts 11a and 12a of the stoppers 11 and 12 are engaged. However, instead, the stoppers 11 and 12 may be provided with fitting recesses, and the bumper 6a may be provided with protruding parts, which can fit with these fitting recesses.
In the first embodiment, the front part of the door 2 is supported by the link mechanism 20 while the rear part is supported by the slide mechanism 30. However, it is possible that both the front and rear of the door be supported either by a link mechanism or by a slide mechanism alone, so each of such cases is described in the following, where components identical to those of the first embodiment are indicated by the same numerals to leave out redundant explanation.
At first, as a second embodiment, a case where both the front and rear parts of the door 2 are supported by a link mechanism 120 is described in reference to
At the rear pat of the door 2, provided is a bumper 106 designed to engage with the stopper 11, which is provided at the rear pat of the cab box 1, when the door 2 is opened, and by this engagement, the door 2 is kept in its opened condition. Also, the bumper 106 is designed to engage with the stopper 12, which is provided approximately at the central part of the cab box 1, when the door 2 is closed, and by this engagement, the door 2 is kept in its closed condition. The bumper 106 has the same shape as the bumper 6a of the slide member 6 in the first embodiment.
Also, in the second embodiment, when the door 2 is closed as shown in
As described above, even though the door 2 is supported only by the link mechanism 120, because the handle 13, the closed door lock 7 and the opened door lock 9 are provided in concentration at the front part of the door 2, the construction of the door 2 is relatively simple. Therefore, it is possible to make the door 2 thin or to make the door 2 with a pipe frame. Furthermore, the door 2 can be provided with a window 14 at the central part of the door 2.
As shown in
As a third embodiment, a case where both the front and rear parts of the door 2 are supported only by slide mechanisms 30, 230 and 240 is described in reference to
The upper slide mechanism 230 comprises an upper slide rail 203, which is attached on the cab box 1 along the upper side of the entrance of the cab box 1, and an upper slide member 303, which slides along the upper slide rail 203. The lower slide mechanism 240 comprises a lower slide rail 204, which is attached on the cab box 1 along the lower side of the entrance, and a lower slide member 304, which slides along the lower slide rail 204.
Also, in the third embodiment, when the door 2 is closed as shown in
As a result, even though the door 2 is supported only by the slide mechanisms 30, 230 and 240, because the handle 13, the closed door lock 7 and the opened door lock 9 are provided in concentration at the front part of the door 2, the construction of the door 2 is relatively simple. Therefore, it is possible to make the door 2 thin or to make it with a pipe frame. Furthermore, the door 2 can be provided with a window 14 at the central part of the door 2.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
This application claims the priority of Japanese Patent Application No. 2004-135878 filed Apr. 30, 2004, which is incorporated herein by reference.
Number | Date | Country | Kind |
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2004-135878 | Apr 2004 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
5564774 | Shinsen | Oct 1996 | A |
6477806 | Asada et al. | Nov 2002 | B1 |
6793268 | Faubert et al. | Sep 2004 | B1 |
7040687 | Ishibashi et al. | May 2006 | B2 |
Number | Date | Country |
---|---|---|
1277607 | Jan 2003 | EP |
2797656 | Feb 2001 | FR |
2328712 | Mar 1999 | GB |
04353129 | Dec 1992 | JP |
Number | Date | Country | |
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20050242624 A1 | Nov 2005 | US |