What is claimed is:
1. A running power transmission mechanism for a vehicle for transmitting drive power from a driving source to steering and steered wheels, which are respectively disposed closer to first and second sides of the vehicle in a fore and aft direction thereof, comprising:
a main-transmission device having a steering-wheel drive output shaft for outputting to the steering wheels drive power, which is synchronized with drive power outputted to the steered wheels;
steering-wheel speed change device for non-stepwisely changing the speed of drive power inputted via the steering-wheel drive output shaft and outputting the drive power to the steering wheels, in which said steering-wheel speed change device is switchable between a standard transmission state, which outputs power enabling the steering wheels to have an average peripheral speed substantially equal to an average peripheral speed of the steered wheels, and a higher speed transmission state, which outputs power enabling the steering wheels to have an average peripheral speed higher than an average peripheral speed of the steered wheels;
said steering-wheel speed change device including:
non-stepwise speed change unit having an output shaft and an output adjusting member so as to output through said output shaft power with its speed non-stepwisely changed based upon an operational state of the output adjusting member, which is operated according to a steering angle of the steering wheels; and
a planetary differential unit having first, second and third elements, the first and second elements designed to respectively receive power from the steering-wheel drive output shaft and power from the output shaft of the non-stepwise speed change unit, and the third element designed to output power therefrom to the steering wheels.
2. A running power transmission mechanism according to claim 1, wherein said non-stepwise speed change unit further includes an input shaft for receiving a part of power from the steering-wheel drive output shaft, and said first element of the planetary differential unit is designed to receive the residual part of the power from the steering-wheel drive output shaft.
3. A running power transmission mechanism according to claim 2, wherein a transmission device is further provided to couple the steering-wheel drive output shaft with the input shaft of the non-stepwise speed change unit, and said transmission device has a clutch member, which is engaged and disengaged to selectively transmit power to said input shaft.
4. A running power transmission mechanism according to claim 2, wherein said non-stepwise speed change unit is an HST, which includes a hydraulic pump body driven by said input shaft, and a hydraulic motor body that is fluidly connected with said hydraulic pump body so as to output through said output shaft power with its speed non-stepwisely changed in cooperation with said hydraulic pump body, and said HST includes a bypass valve in a hydraulic passage for fluid connection between said hydraulic pump body and said hydraulic motor body.
5. A running power transmission mechanism according to claim 1, wherein said output adjusting member is operated so that an average peripheral speed of the steering wheels is increased and a rate of increase in said average peripheral speed of the steering wheels relative to a displacement of the steering angle of the steering wheels is accelerated, as the steering angle of the steering wheels is enlarged.
6. A running power transmission mechanism according to claim 1, wherein said main-transmission device is an HST, which includes a main-input shaft operatively connected with the driving source, a hydraulic pump body driven by said main-input shaft, and a hydraulic motor body that is fluidly connected with said hydraulic pump body so as to output through said steering-wheel drive output shaft power with its speed non-stepwisely changed in cooperation with said hydraulic pump body.
7. A running power transmission mechanism according to claim 1, wherein said steering-wheel speed change device is detachably attached to said main-transmission device.
8. A running power transmission mechanism according to claim 1, wherein said non-stepwise speed change unit further includes an input shaft for receiving constant power from said driving source, and said output adjusting member is controlled based upon the steering angle and the average peripheral speed of the steering wheels, and the rotational direction and the average peripheral speed of the steered wheels so that the steering wheels and the steered wheels are rotated in synchronization with each other when the steering wheels are in a straight travelling state, and the speed of the steering wheels is increased as the steering angle of the steering wheels is enlarged when the steering wheels are in a turning state.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A bracelet assembly for moving sensor modules around a pipe, comprising:
a frame adapted for installation around the pipe;
supports adapted to receive the sensor modules;
a sliding arrangement slideably mounted onto the frame and guiding a displacement of the supports in periphery of the pipe, the sliding arrangement comprising attachments spaced apart from one another and receiving the supports in periphery of the pipe;
a first driving means for controllably driving the sliding arrangement and thereby displacing the supports in periphery of the pipe at desired operating positions;
biasing means for biasing the sensor modules against the pipe;
wheel arrangements distributed around the frame and projecting therefrom for engagement with the pipe and displacement of the frame along an axial direction of the pipe; and
a second driving means for controllably driving the wheels in rotation and thereby displacing the frame along the axial direction of the pipe at a desired operating position.
2. The bracelet assembly according to claim 1, wherein the sliding arrangement comprises a slideable member to which the supports are attached, and a guide member extending on the frame and slideably receiving the slideable member for sliding along a predetermined sliding range of the peripheral course.
3. The bracelet assembly according to claim 2, wherein:
the frame has a circular shape and a pair of circular members spaced apart from each other, the guide member being provided on one of the circular members;
the slideable member has a hoop shape and extends between the circular members; and
one of the guide member and the slideable member having elongated grooves extending concentrically with respect to the peripheral course, the other of the guide member and the slideable member having pins engaging in the grooves.
4. The bracelet assembly according to claim 3, wherein:
the slideable member has a pair of curved arms spaced from one another and extending between the circular members of the frame, the pins projecting from the curved arms, the grooves extending on opposite sides of the circular arms and facing one another.
5. The bracelet assembly according to claim 4, wherein:
each of the supports comprises an elongated connecting rod mounted to the curved arms and extending substantially transversally between the curved arms, the connecting rod has opposed ends projecting from the curved arms and engaging in the grooves.
6. The bracelet assembly according to claim 3, wherein:
the slideable member has an elongated rack extending along a length thereof; and
the first driving means has a driving pinion mounted onto the frame and engaging with the rack so that the pinion and the rack form a rack-and-pinion gear operable for producing a reciprocating motion of the sensor modules along the peripheral course.
7. The bracelet assembly according to claim 1, wherein:
the sensor modules comprise ultrasonic transducers and wedges having bottom surfaces matching an outer peripheral surface of the pipe and surfaces receiving the transducers at a predetermined angle with respect to the peripheral surface of the pipe, the wedges being pivotally attached to the supports.
8. The bracelet assembly according to claim 7, wherein each sensor module comprises two wedge and ultrasonic transducers assemblies pivotably mounted next to each other along the peripheral course around the pipe.
9. The bracelet assembly according to claim 7, wherein each support comprises a pair of arms operatively connected to the sliding arrangement and between which one of the sensor modules is pivotally mounted.
10. The bracelet assembly according to claim 8, wherein each support comprises a pair of arms operatively connected to the sliding arrangement and between which the two wedge and ultrasonic transducer assemblies are pivotally mounted.
11. The bracelet assembly according to claim 10, wherein the biasing means comprises a return spring element extending between each wedge of the two wedge and ultrasonic transducer assemblies at a lower level than a pivot point of the wedges.
12. The bracelet assembly according to claim 1, wherein the supports respectively comprise reciprocating arrangements coupled to the first driving means and guided by the sliding arrangement for oscillation along the peripheral course.
13. The bracelet assembly according to claim 12, wherein:
the first driving means comprises rotating shafts mounted in the frame; and
the supports have ends provided with connecting rods pivotably attached to the rotating shafts and producing reciprocating motions of the supports.
14. The bracelet assembly according to claim 2, wherein:
the slideable member extends on a front side of the frame around the pipe; and
the supports project from the slideable member away from the front side of the frame.
15. The bracelet assembly according to claim 14, wherein:
each support comprises a mounting bracket removably mounted to the slideable member; and
the slideable member has receiving surfaces extending along a length thereof, the mounting brackets being fastened to the receiving surfaces.
16. The bracelet assembly according to claim 15, wherein the receiving surfaces are extending on a front side of the slideable member around the pipe.
17. The bracelet assembly according to claim 14, wherein:
the supports comprise pair of arms pivotally mounted to the mounting brackets and between which the sensor modules extend; and
the biasing means comprises torsion springs extending between the mounting brackets and the pair of arms.
18. The bracelet assembly according to claim 1, wherein the wheel arrangements comprise magnetized wheels.