HIGH-CAB-CARRYING LOW SWINGABLE WORKING VEHICLE

Abstract

 A high-cab-carrying low swingable working vehicle using a large-capacity bucket and a cab which are adapted to be attached to the vehicle on a job site in which the height of a vehicle is limited; and capable of completing work within a term of work. Accordingly, a floor (47b) of a swingable frame (47) is provided with an opening (47d) formed by a bore concentric with an axis (48) of swing, a cylindrical member (47a) fixed to an edge portion of this bore and opened in the downward direction, and a lower floor portion (50) fixed to a lower portion of the cylindrical member (47a), the lower floor portion (50) being provided with footsteps (55a, 55b) for an operator (3).

Description

TECHNICAL FIELD

[0001] The present invention relates to a cab-carrying swingable working vehicle with low height, and more particularly to a cab-carrying swingable working vehicle with low height which has crawler belts or wheels and is adapted for operation in a job site where the height of a vehicle is limited.

BACKGROUND ART

[0002] Heretofore, as shown in Fig. 10, a swingable working vehicle, e.g., a hydraulic shovel 100, operating in a structure 1 where the vehicle height is limited to L (about 1.8 to 2.1 m), has footsteps 50 for an operator 3 provided on a swingable frame 47 above (height h) an undercarriage 23 having a vertical dimension C. For a working vehicle provided with a cab 101 for protecting the operator 3, the overall height of the cab 101 is given by the sum of a dimension B required for the operator 3 to perform work while sitting in the cab and a protection gap A left above the operator's head. Other examples imposing a limit L on the vehicle height in a job site are ceilings of galleries in mining, shelves or shelf supports in farms, beams and ceilings of vinyl plastic hothouses and greenhouses, ceilings of buildings, underground passages and water conduits, etc.

[0003] When a working vehicle is employed to perform work within the limit L on the vehicle height, the dimension C of the undercarriage 23 must be made smaller because the dimension B required for the operator 3 to perform work while sitting in the cab is fixed. Therefore, the size of a working attachment 102 is reduced and a working vehicle called a mini-hydraulic shovel is usually employed. In such a mini-hydraulic shovel, the capacity of a bucket 103 is as small as about 0.01 to 0.03 m³.

[0004] Also, as shown in Fig. 11, when a hydraulic shovel 110 equipped with a working attachment 112 including a large-sized bucket 113 is used to increase the working efficiency, a cab 111 interferes with the ceiling of the structure 1 or the like because of a difference La between the overall height of the cab 111 and the limit L of the vehicle height in the structure 1. If the hydraulic shovel 110 is operated with the cab 111 removed, there would occur a risk that the operator's head may hit against the structure 1. From this reason, when employing such a large-sized working vehicle, the vehicle is operated under radio or other remote control with the cab 111 removed and no operator boarding on the vehicle.

[0005] As shown in Fig. 12, a water conduit working machine 120 known as another prior art includes an upper swingable turret 20 mounted on an undercarriage 23 through a swing circle 64, and an operator's seat 123 provided in a lower position 122 on one side 121 of the upper swingable turret 20 (see, e.g., Japanese Unexamined Utility Model Publication No. 63-156238). Further, a boom 124 is tiltably attached to a front portion of the upper swingable turret 20, and a bucket 125 is attached to a fore end of the boom 124. The bucket 125 is attached in a vertically pivotal manner and the operator's seat 123 has substantially an L-shape.

[0006] However, the hydraulic shovels 100, 110 and the water conduit working machine 120 have problems below when operated in a job site where there is a limit L on the vehicle height.

(I) When the cab-carrying mini-hydraulic shovel 100 is employed to excavate earth and sand, the small capacity of the bucket 103 requires it to increase the number of mini-hydraulic shovels 100 used in order to complete scheduled work within a term of the work. Also, in the case of the weak ground, because the mini-hydraulic Shovel 100 has a small minimum height K from the ground (see Fig. 10), the undercarriage 23 with crawler belts causes a slip upon the earth and sand raised due to sinking of the vehicle body, resulting in the reduced working efficiency.

(II) When the hydraulic shovel 110 having the large-capacity bucket 113 and hence a great capability is employed to complete scheduled work within a term of the work, the cab 111 interferes with the structure 1 or the like which imposes a limit L on the vehicle height. If the cab 111 is removed to prevent such an interference, there would occur a risk that the operator's head may hit against the overhead structure 1 or the like while the operator is sitting to operate the vehicle. Further, when the hydraulic shovel is operated with no cab, the operator is prohibited from boarding on the vehicle from the safety point of view.

(III) When a working vehicle is operated under radio or other remote control with the cab 111 removed, a great deal of skill is required to perform excavation of earth and sand by delicately manipulating the bucket 113 in such work as digging or setting corners. Also, in this remote control method, because of the operator not boarding on the vehicle, the operator often cannot view the position where the bucket tip is digging, and hence encounters a difficulty in operation. As a result, the operator tends to feel much fatigued and cannot continue work for a long time, leading to a reduction in working efficiency.

DISCLOSURE OF THE INVENTION

[0007] The present invention has been accomplished to solve the above-mentioned problems in the prior art, and its first object is to provide a cab-carrying swingable working vehicle with low height which allows an operator to board thereon, has a large-sized working attachment including a large-capacity bucket, and is capable of completing work within a term of the work in a job site, e.g., in the above-mentioned structure 1, where there is a limit L on the vehicle height.

[0008] A second object is to provide a cab-carrying swingable working vehicle with low height which allows an operator to board thereon and makes the operator feel less fatigued even when the operator continues excavation of earth and sand for such work as digging or setting corners by delicately manipulating a bucket.

[0009] A first aspect of the cab-carrying swingable working vehicle with low height according to the present invention resides in a swingable working vehicle comprising an undercarriage having crawler belts or wheels, and an upper swingable turret swingably supported on the undercarriage by a swing circle, the upper swingable turret mounting thereon a drive source such as an engine, a cab for protecting an operator, tanks, controls, a working attachment etc., wherein a floor of a swingable frame for the upper swingable turret is provided with an open space formed jointly by a bore concentric with an axis of swing of the swingable frame, a cylindrical member fixed to a peripheral edge of the bore and being open downward, and a lower floor portion fixed to a lower portion of the cylindrical member and positioned at a level lower than an upper surface of the undercarriage, the lower floor portion being located at a level allowing an operator to rest feet on the lower floor portion. Also, an operator's seat floor comprising a substantially box-shaped member being open upward and provided with footsteps for the operator, and a cab floor including a seat attached thereto in a position substantially the same as or lower than the level of the floor may be disposed in the open space, the footsteps and the seat being swingable about the axis of swing.

[0010] The arrangement may be such that a cylindrical recess being open upward and concentric with the axis of swing is formed in a center frame of the undercarriage, and the swing circle is disposed between the cylindrical recess and the lower floor portion of the cylindrical member fitting into the cylindrical recess, the cylindrical member being swingably coupled to the undercarriage. Also, the swing circle may be made up of a swing circle outer race attached to the lower floor portion and a swing circle inner race attached to the cylindrical recess, and the cylindrical member may include therein a swing motor provided with a pinion, the swing circle inner race being meshed with the pinion. Further, the fixing of the cylindrical member to the peripheral edge of the bore may be effected by attaching a cylindrical member having an upper flange at an upper end of the cylindrical member to the peripheral edge of the bore.

[0011] A second aspect of the cab-carrying swingable working vehicle with low height resides in a swingable working vehicle comprising an undercarriage having crawler belts or wheels, and an upper swingable turret swingably supported on the undercarriage by a swing circle, the upper swingable turret mounting thereon a drive source such as an engine, a cab for protecting an operator, tanks, controls, a working attachment, etc., wherein a floor of a swingable frame for the upper swingable turret has an opening formed therein to encircle an axis of swing of the swingable frame in concentric relation, and a substantially box-shaped member having a lower floor portion at the bottom and being open upward is fixed to the underside of an edge of the opening, thereby defining an open space, the lower floor portion being positioned at a level lower than an upper surface of the undercarriage, and the lower floor portion being provided with footsteps for an operator. Further, a cab floor connected to the substantially box-shaped member and including a seat attached thereto in a position substantially the same as or lower than the level of the floor may be formed in the floor.

[0012] The arrangement may be such that a cylindrical recess being open upward and concentric with the axis of swing is formed in a center frame of the undercarriage, and a swing circle made up of a swing circle inner race attached to an upper end of the cylindrical recess and a swing circle outer race attached to the underside of the swingable frame outwardly of an outermost edge of the substantially box-shaped member, the swingable frame being swingably coupled to the undercarriage. Also, a sing motor provided with a pinion may be disposed on the swingable frame, and the swing circle inner race is meshed with the pinion.

[0013] The above first and second aspects may additionally include the following arrangements. A front floor portion may be provided in the floor of the swingable frame forwardly of the open space, and an upper footstep may be provided on the front floor portion. Also, travel control members may be installed inside the substantially box-shaped member. Further, working attachment control members may be installed on the left and right sides of the seat or on the lower floor portion, and a travel control member may be installed on the front floor portion of the floor forwardly of the open space.

[0014] With the first and second aspects thus constituted, since the footsteps and the seat for the operator are provided at a level lower than conventional, the ceiling height of the cab can be reduced and the overall height of the vehicle can be also reduced so as to meet a limit L on the vehicle height. Even when operating the vehicle under a limit L on the vehicle height, the operator can view the digging point of a bucket of the working attachment while sitting in a normal working posture. In addition, with the cylindrical member fitted into the cylindrical recess, it is possible to further lower the level of the lower floor portion and increase a space around the legs of the operator correspondingly.

[0015] In the arrangement that the upper flange of the cylindrical member is attached to the peripheral edge of the bore in the swingable frame, the swingable frame and the cylindrical member can be machined as separate parts independently of each other and, therefore, the present invention is applicable to a large-sized working vehicle as well. In the arrangement including the upper footstep provided on the front floor portion, the operator can select one of the upper footstep and the footstep on the lower floor portion depending on work situations. Also, in the arrangement that the swing circle is provided below the lower floor portion, the footsteps can be disposed in a proper position within the area in which the operator can smoothly perform operation by the legs. Further, in the arrangement that the swing circle is provided outwardly of the substantially box-shaped member, the footsteps on the lower floor portion can be positioned at an even lower level corresponding to the thickness of the swing circle.

[0016] Moreover, by providing the travel control members inside the substantially box-shaped member, a space around the operator's arms is increased to permit smooth operation to perform work. Additionally, by providing the travel control member and the working attachment control members respectively on the front floor portion and the lower floor portion, it is easier for the operator to select the control lever location depending on work to be performed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 

Fig. 1 is a side view of a cab-carrying swingable working vehicle with low height according to a first embodiment of the present invention, the vehicle having crawler belts,

Fig. 2 is a sectional view taken along line II-II in Fig. 1,

Fig. 3 is a partial vertical sectional view of the cab-carrying swingable working vehicle with low height according to the first embodiment,

Fig. 4 is a partial vertical sectional view of a cab-carrying swingable working vehicle with low height according to a second embodiment of the present invention, the vehicle having crawler belts,

Fig. 5 is a side view of a cab-carrying swingable working vehicle with low height according to a third embodiment of the present invention, the vehicle having wheels,

Fig. 6 is a partial vertical sectional view of the cab-carrying swingable working vehicle with low height according to the third embodiment,

Fig. 7 is a partial vertical sectional view of a cab-carrying swingable working vehicle with low height according to a fourth embodiment of the present invention, the vehicle having crawler belts,

Fig. 8 is a sectional view taken along line VIII-VIII in Fig. 7,

Fig. 9 is a partial vertical sectional view of main part of a cylindrical member, the view showing another example of a cylindrical member in Fig. 7,

Fig. 10 is a side view of a min-hydraulic shovel according to the prior art,

Fig. 11 is a side view of a standard hydraulic shovel according to the prior art, and

Fig. 12 is a side view of a water conduit working vehicle according to the prior art.

BEST MODE FOR CARRYING OUT THE INVENTION

[0018] Preferable embodiments of a cab-carrying swingable working vehicle with low height according to the present invention will be described in detail with reference to the accompanying drawings.

[0019] A first embodiment will be described with reference to Figs. 1 to 3.

[0020] In Fig. 1, a cab-carrying swingable working vehicle 2 mainly comprises a crawler belt type undercarriage 23 and an upper swingable turret 20. The cab-carrying swingable working vehicle 2 is adapted to be operated in a job site where there is a limit L on the vehicle height, e.g., in the structure 1, or where the ground is weak in addition to such a dimensional limit, as stated above in connection with the prior art.

[0021] The crawler belt type undercarriage 23 has track frames 30 on each of which are assembled an idler 31, a carrier roller 32, a center frame 33, track rollers 34, and a final drive 35. The undercarriage 23 can travel over an uneven ground often existing in a job site by driving crawler belts 37 on both the left and right sides which are meshed with sprockets 36. Incidentally, G.L denotes a ground level on which the working vehicle performs excavation.

[0022] The upper swingable turret 20 is made up of a drive source 24 comprising an engine or the like, a cab 25 for protecting an operator, tanks, controls, a working attachment 26, etc., as well as a swingable frame 47. The swingable frame 47 is supported on the center frame 33 and swingably mounted to a swing circle 64 (see Fig. 3).

[0023] The working attachment 26 comprises a boom 40, an arm 41, links 42 and a bucket 43 which are pivotally connected to each other by respective pins 46. The working attachment 26 also includes a boom cylinder (not shown), an arm cylinder 44 and a bucket cylinder 45 which are driven by a hydraulic source, thereby excavating earth and sand. In Fig. 1, the bucket indicated by 43a represents a position at which a digging stroke is completed, 43b represents an earth carrying position, 43c represents an earth discharging position, and 43e represents a digging point, respectively. Thus, the working vehicle can freely perform excavation work within the dimension under the limit L on the vehicle height by using the bucket 43. Note that the working attachment 26 may be a conventional working attachment including, e.g., the large-sized bucket 43.

[0024] In Fig. 2, a floor 47b of the swingable frame 47 has formed therein a circular bore concentric with an axis 48 of swing of the swingable frame 47. A cylindrical member 47a being open downward is fixed to a peripheral edge of the cylindrical bore and a lower floor portion 50 is fixed to a lower portion of the cylindrical member 47a, the cylindrical member 47a and the lower floor portion 50 providing an outermost edge 50a. In other words, the cylindrical member 47a and the lower floor portion 50 jointly define an open space 47d. The cylindrical member 47a is positioned inwardly of the left and right crawler belts 37 to be out of interference with the crawler belts 37. The cylindrical member 47a is swingable 360 degrees on the center frame 33 about the axis 48 of swing of the swingable frame 47.

[0025] The cab 25 is mounted over the floor 47b of the swingable frame 47 having the aforesaid circular bore formed therein, with a cab floor 49 provided in the cab 25. The cab floor 49 is attached to the floor 47b and the lower floor portion 50 while leaving a gap enough to prevent its interference with the tops of both a swivel joint 60 for introducing a fluid from the upper swingable turret 20 to the undercarriage 23 and a swing motor 61 for swinging the upper swingable turret 20. If the swivel joint 60 and the swing motor 61 are so flat as to leave a gap relative to the cab floor 49, the cab floor 49 may be at a level coplanar with or below that of the floor 47b.

[0026] Disposed in the cab 25 is a seat 51 on the cab floor 49 near the axis 48 of swing. Working attachment control members 53a, 53b including working attachment levers 52a, 52b, etc. are disposed on the left and right sides of the seat 51, respectively. Also, disposed on the lower floor portion 50 are travel control members 54a, 54b such as travel levers for driving the left and right crawler belts 37, the travel control members 54a, 54b being connected to tread pedals 55a, 55b depressed by the operator's feet, respectively. Outwardly of the tread pedals 55a, 55b, there are provided respectively footsteps 56a, 56b on which the feet of the operator 3 are rested when the travel operation is not performed. The travel control members 54a, 54b, the footsteps 56a, 56b, etc. are provided on the lower floor portion 50 defining the bottom of a substantially box-shaped member 47e (see Figs. 2 and 3).

[0027] In Fig. 3, the swivel joint 60 is mounted coaxially with the axis 48 of swing on the center frame 33 having a cylindrical recess 33a, and supplies a fluid to a travel motor incorporated in the final drive 35 (Fig. 1). The swing motor 61 is mounted on the swingable frame 47 and fixed thereto by bolts 62.

[0028] The swing circle 64 is made up of a swing circle inner race 65 (hereinafter referred to as an inner race 65), a swing circle outer race 66 (hereinafter referred to as an outer race 66), and a ball bearing 67. The inner race 65 is meshed with a pinion 63 attached to an axial end of the swing motor 61. The outer race 66 is secured to the lower floor portion 50 of the cylindrical member 47a by bolts 68, and the inner race 65 is secured to the bottom of the cylindrical recess 33a of the center frame 33 by bolts 68.

[0029] A seal 69 is secured to an upper enf of the cylindrical recess 33a so that the cylindrical member 47a can be rotated while earth and sand are prevented from entering the gap between the cylindrical recess 33a and the rotating cylindrical member 47a.

[0030] In this embodiment, as described above, since the open space 47d is formed by providing the lower floor portion 50 at a level one step lower than the cab floor 49 and the footsteps 56a, 56b are provided on the bottom (i.e., the lower floor portion 50) of the substantially box-shaped member 47e, the seat 51 can be disposed in a lower position. It is therefore possible to reduce the height of the cab 25 and realize a cab-carrying swingable working vehicle with low height. In other words, since the vehicle height can be reduced even with the large-capacity bucket 43 mounted, it is possible to employ a working vehicle carrying the cab 25, which is preferable from the safety point of view, in a job site where there is a limit L on the vehicle height, and to improve the working efficiency. As a result, scheduled work can be safely completed within a term of the work.

[0031] Further, as shown in Fig. 1 or 3, the operator 3 in a normal working posture sitting in the cab can view, from a level of eyes 3b, the digging point 43e of the bucket 43 of the working attachment 26. Accordingly, while visually checking situations, the operator 3 can perform operations of turning to the left, turning to the right, arm digging and arm dumping by manipulating the working attachment lever 52a on the left side, and operations of boom-up, boom-down, bucket dumping and bucket digging by manipulating the working attachment lever 52b on the right side. Upon the operator 3 treading the travel pedals 55a, 55b by legs 3a, the combined operation of any of the above operations and movement of the working vehicle can be easily effected. In addition, even when excavating earth and sand by delicately manipulating a bucket, e.g., in such work as digging or setting corners, the operator 3 boarding on the vehicle can view the digging point 43e and hence perform the delicate operation with ease. As a result, the operator 3 feels less fatigued and can continue work for a long time, and the working efficiency is improved.

[0032] Next, a second embodiment of the cab-carrying swingable working vehicle with low height according to the present invention will be described with reference to the drawing as to points differing from the first embodiment.

[0033] In Fig. 4, an opening encircling the axis 48 of swing in concentric relation is formed in the floor 47b of the swingable frame 47, and a substantially box-shaped member 47e having a lower floor portion 50 at the bottom and being open upward is fixed to the underside of an edge of the opening, thereby defining an open space 47d. The substantially box-shaped member 47e is similarly constructed to that in the first embodiment; namely, the lower floor portion 50 is positioned below the upper surface of the undercarriage 23 and the footsteps 56a, 56b (see Fig. 2) for the operator 3 are disposed on the lower floor portion 50. Note that the cylindrical member 47a is not provided in this embodiment. A swing circle 64 has an inner diameter selected to be out of interference with an outermost edge 50a of the substantially box-shaped member 47e during swing of the swingable frame 47. Further, an outer race 66 is attached to the underside of the swingable frame 47 in a portion 49b outwardly of the an aforesaid bore, and an inner race 65 is attached to upper edge of the cylindrical recess 33a of the center frame 33.

[0034] In this embodiment thus constructed, the lower floor portion 50 is located at a level one step lower than the cab floor 49 by a larger distance corresponding to the thickness of the swing circle 64. Therefore, the footsteps 56a, 56b (see Fig. 2) on the lower floor portion 50 can be located in an even lower position, and a large-capacity working vehicle mounting a larger-sized working attachment and having a larger minimum height K from the ground can be realized for practical use. As an alternative, a cab-carrying swingable working vehicle with low height can be employed even in a job site imposing a severer limit L on the vehicle height.

[0035] Next, a third embodiment of the cab-carrying swingable working vehicle with low height according to the present invention will be described with reference to the drawings. In this embodiment, the crawler belt type undercarriage 23 is replaced by a wheel type undercarriage.

[0036] In Fig. 5, a cab-carrying swingable working vehicle 2 with low height, which has wheels, comprises a wheel type undercarriage 70 and an upper swingable turret 20. The working vehicle 2 of this embodiment is adapted, as with the foregoing one, to be operated in a job site where there is a limit L on the vehicle height, e.g., in the structure 1, or where the ground is weak in addition to such a dimensional limit.

[0037] The wheel type undercarriage 70 includes a frame 73 from which a front axle 77 and a rear axle 76 are suspended. Wheels 71 are attached to left and right ends of each of the front axle 77 and the rear axle 76. In the illustrated embodiment, the wheels are each provided as a dual wheel as indicated by 71, 72 in Fig. 6, but may be each a single wheel. Front fenders 74 and rear fenders 75 serving as mudguards for the front and rear wheels 71 are assembled to the frame 73.

[0038] The upper swingable turret 20 is made up of a drive source 24 comprising an engine or the like, a cab 25, tanks, controls, a working attachment 26, etc., as well as a swingable frame 47. The swingable frame 47 is swingably mounted to a swing circle 64 (see Fig. 6) which is supported on the frame 73. The construction of the working attachment 26, respective operating positions of a bucket 43 such as a position 43a at which a digging stroke is completed, and free operability within a limit L on the vehicle height are the same as in the first embodiment.

[0039] In Fig. 6, a swivel joint 60 is mounted coaxially with a axis 48 of swing of the swingable frame 47 on the frame 73 having a cylindrical recess 33a, and supplies a fluid to travel devices (not shown) incorporated in the front axle 77 and the rear axle 76.

[0040] As with the first embodiment, the swingable frame 47 includes a cylindrical member 47a fixed to a floor 47b and a lower floor portion 50 is fixed to a lower portion of the cylindrical member 47a, the cylindrical member 47a and the lower floor portion 50 providing an outermost edge 50a. The lower floor portion 50 is positioned below respective tops of the wheels 71. Further,, the lower floor portion 50 and the cylindrical member 47a are positioned inwardly of the left and right wheels 71 and constructed to be out of interference with the wheels 71. The cylindrical member 47a, etc. are swingable 360 degrees in the cylindrical recess 33a about the axis 48 of swing.

[0041] A swing motor 61 is mounted on the lower floor portion 50 and fixed thereto by bolts 62. An outer race 66 and an inner race 65 of the swing circle 64 are secured to the lower floor portion 50 and the bottom of the cylindrical recess 33a by bolts 68, respectively. The arrangement and operation of a seal 69 and the attachment of the cab 25 are the same as in the first embodiment.

[0042] As described above, since the open space 47d is formed by providing the lower floor portion 50 at a level one step lower than the tops of the wheels 71, a sufficient space for operation is ensured around feet and legs 3a of the operator 3 while the operator is sitting within the cab 25 in a normal working posture. Also, as with the first embodiment, the operator can perform any desired operation by manipulating working attachment levers 52a, 52b on the left and right sides, while viewing a digging point 43e of the bucket 43. Further, the operator 3 can drive and brake the working vehicle by depressing accelerator and brake pedals 55 for travel control by the legs 3a, resulting in that the combined operation can be easily effected.

[0043] Next, a fourth embodiment of the cab-carrying swingable working vehicle with low height according to the present invention will be described with reference to the drawing. In this embodiment, part of the upper swingable turret is modified in comparison with the first embodiment and hence only points differing from the first embodiment will be described below.

[0044] In Figs. 7 and 8, a cylindrical member 87a concentric with the axis 48 of swing is fixed to the floor 47b of the swingable frame 47 so as to extend downward. A cylindrical member 88a having a lower floor portion 50 fixed thereto is attached at its upper flange 88b to a lower flange 87b of the cylindrical member 87a. An open space 47d is thereby defined below the floor 47b. The cylindrical member 88a is swingably fitted in the cylindrical recess 33a of the center frame 33.

[0045] On a front floor portion 47c of the floor 47b forwardly of the open space 47d, there are disposed a travel control member 54 such as a travel control lever on the left side and an upper footstep 56 on the right side, respectively. The travel control member 54 in this embodiment comprises two stick levers. On the lower floor portion 50 inwardly of and near the axis 48 of swing, there are disposed a bucket type seat 51a, footsteps 56a, 56b, and working attachment control members 53a, 53b including working attachment levers 52a, 52b, etc. The seat 51a is positioned on the cab panel 49 above the swing motor 61.

[0046] Further, as with the foregoing embodiment, the lower floor portion 50 and the cylindrical member 88a providing a lower floor portion outermost edge 50a are positioned inwardly of the left and right crawler belts 37 to be out of interference with the crawler belts 37, and are swingable 360 degrees in the cylindrical recess 33a. Additionally, the cab floor 49 may be positioned, as with the foregoing embodiment, at a level coplanar with or below that of the floor 47b of the swingable frame 47.

[0047] The cylindrical members 87a, 88a may be modified to be replaced by the cylindrical member 88a as shown in Fig. 9. More specifically, the cylindrical member 88a in Fig. 9 is extended upward from the upper end of the cylindrical member 88a in Fig. 7 corresponding to the height of the cylindrical member 87a, and is directly attached at its upper flange 88b to the underside of the floor 47b. This attachment can be made by any conventional method such as fastening by bolts or the like and permanent securing by welding or the like.

[0048] The above fourth embodiment also allows the operator 3 to perform work under visual checking similarly to the foregoing embodiments. Also, since the operator 3 can select the footstep 56b on the lower floor portion 50 or the upper footstep 56 depending on work situations, the operator is less fatigued during operation. Further, since the travel control member 54 is disposed on the front floor portion 47c and the working attachment control members 52a, 52b are disposed on the lower floor portion 50, it is easier for the operator to select the control lever location depending on work to be performed. In addition, the use of the cylindrical member 88a shown in Fig. 9 enables the cylindrical member 88a and the swingable frame 47 to be machined separately from each other, which is particularly effective in a large-sized working vehicle.

INDUSTRIAL APPLICABILITY

[0049] The present invention is usefully practiced as a cab-carrying swingable working vehicle with low height which allows an operator to board on the vehicle, can mount a large-capacity bucket thereon, and is capable of completing scheduled work within a term of the work in a job site, e.g., in a structure, where the height of a vehicle is limited, and which makes the operator feel less fatigued even when the operator continues excavation of earth and sand for such work as digging or setting corners by delicately manipulating a bucket.

Claims

1. A cab-carrying swingable working vehicle with low height comprising an undercarriage (23) having crawler belts (37) or wheels (71), and an upper swingable turret (20) swingably supported on said undercarriage (23) by a swing circle (64), said upper swingable turret (20) mounting thereon a drive source (24) such as an engine, a cab for protecting an operator, tanks, controls, a working attachment (26), etc., wherein:
   a floor (47b) of a swingable frame (47) for said upper swingable turret (20) is provided with an open space (47d) formed jointly by a bore concentric with an axis (48) of swing of said swingable frame (47), a cylindrical member (47a) fixed to a peripheral edge of said bore and being open downward, and a lower floor portion (50) fixed to a lower portion of said cylindrical member (47a) and positioned at a level lower than an upper surface of said undercarriage (23), said lower floor portion (50) being located at a level allowing an operator (3) to rest feet on said lower floor portion (50).

2. A cab-carrying swingable working vehicle with low height according to Claim 1, wherein an operator's seat floor comprising a substantially box-shaped member (47e) being open upward and provided with footsteps (56a, 56b) for the operator (3), and a cab floor (49) including a seat (51) attached thereto in a position substantially the same as or lower than the level of said floor (47b) is disposed in said open space (47d), said footsteps (56a, 56b) and said seat (51) being swingable about said axis (48) of swing.

3. A cab-carrying swingable working vehicle with low height according to Claim 1 or 2, wherein a cylindrical recess (33a) being open upward and concentric with said axis (48) of swing is formed in a center frame (33) of said undercarriage (23), and said swing circle (64) is disposed between said cylindrical recess (33a) and the lower floor portion (50) of said cylindrical member (47a) fitting into said cylindrical recess (33a),
   said cylindrical member (47a) being swingably coupled to said undercarriage (23).

4. A cab-carrying swingable working vehicle with low height according to Claim 3, wherein said swing circle (64) is made up of a swing circle outer race (66) attached to said lower floor portion (50) and a swing circle inner race (65) attached to said cylindrical recess (33a), and said cylindrical member (47a) includes therein a swing motor (61) provided with a pinion (63),
   said swing circle inner race (65) being meshed with said pinion (63).

5. A cab-carrying swingable working vehicle with low height according to Claim 1, wherein the fixing of said cylindrical member (47a) to the peripheral edge of said bore is effected by attaching a cylindrical member (88a) having an upper flange (88b) at an upper end of said cylindrical member (88a) to the peripheral edge of said bore.

6. A cab-carrying swingable working vehicle with low height comprising an undercarriage (23) having crawler belts (37) or wheels (71), and an upper swingable turret (20) swingably supported on said undercarriage (23) by a swing circle (64), said upper swingable turret (20) mounting thereon a drive source (24) such as an engine, a cab for protecting an operator, tanks, controls, a working attachment (26), etc., wherein:
   a floor (47b) of said swingable frame (47) for said upper swingable turret (20) has an opening formed in to encircle an axis (48) of swing of said swingable frame (47) in concentric relation, and a substantially box-shaped member (47e) having a lower floor portion (50) at the bottom and being open upward is fixed to the underside of an edge of said opening, thereby defining an open space (47d),
   said lower floor portion (50) being positioned at a level lower than an upper surface of said undercarriage (23), and said lower floor portion (50) being provided with footsteps (56a, 56b) for an operator (3).

7. A cab-carrying swingable working vehicle with low height according to Claim 6, wherein a cab floor (49) connected to said substantially box-shaped member (47e) and including a seat (51) attached thereto in a position substantially the same as or lower than the level of said floor (47b) is formed in said floor (47b).

8. A cab-carrying swingable working vehicle with low height according to Claim 6 or 7, wherein a cylindrical recess (33a) being open upward and concentric with said axis (48) of swing is formed in a center frame (33) of said undercarriage (23), and a swing circle (64) made up of a swing circle inner race (65) attached to an upper end of said cylindrical recess (33a) and a swing circle outer race (66) attached to the underside of said swingable frame (47) outwardly of an outermost edge (50a) of said substantially box-shaped member (47e),
   said swingable frame (47) being swingably coupled to said undercarriage (23).

9. A cab-carrying swingable working vehicle with low height according to Claim 8, wherein a swing motor (61) provided with a pinion (63) is disposed on said swingable frame (47), and said swing circle inner race (65) is meshed with said pinion (63).

10. A cab-carrying swingable working vehicle with low height according to Claim 2 or 6, wherein a front floor portion (47c) is provided in the floor (47b) of said swingable frame (47) forwardly of said open space (47d), and an upper footstep (56) is provided on said front floor portion (47c).

11. A cab-carrying swingable working vehicle with low height according to Claim 2 or 7, wherein travel control members (54a, 54b) are installed inside said substantially box-shaped member (47e).

12. A cab-carrying swingable working vehicle with low height according to Claim 2 or 7, wherein working attachment control members (52a, 52b) are installed on the left and right sides of said seat (51) or on said lower floor portion (50), and a travel control member (54) is installed on the front floor portion (47c) of said floor (47b) forwardly of said open space (47d).

Drawing