Source: https://patents.justia.com/patent/20090256280
Timestamp: 2020-07-04 03:46:23
Document Index: 430819622

Matched Legal Cases: ['art 23', 'art 23', 'art 23', 'art 23', 'art 23', 'art 23', 'art 22', 'art 22', 'art 22', 'art 23']

US Patent Application for CRAWLER BELT, CRAWLER UNIT AND METHOD FOR MANUFACTURING CRAWLER BELT Patent Application (Application #20090256280 issued October 15, 2009) - Justia Patents Search
Justia Patents Positioning Or Maintaining Position Of Preform Relative To Mold SurfaceUS Patent Application for CRAWLER BELT, CRAWLER UNIT AND METHOD FOR MANUFACTURING CRAWLER BELT Patent Application (Application #20090256280)
Jun 24, 2009 - TOKYO INSTITUTE OF TECHNOLOGY
Theme To provide a crawler unit having a light-weight and high-strength crawler belt. Means to Solve A crawler belt 20 comprises an endless steel belt 21 (high-tensile-strength belt) and a belt main body 22 made of rubber and attached around an outer periphery of the steel belt 21. The steel belt 21 has engagement holes 21a arranged at even intervals in a circumferential direction thereof. The belt main body 22 has escape recesses 23a formed therein. A wheel 10 has projections 12a arranged at even intervals in a circumferential direction on an outer peripheral surface thereof. The projections 12a are adapted to be engaged with the engagement holes 21a of the steel belt 21 and at the same time to enter the escape recesses 23a of the belt main body 22.
ARTIFACTLESS SUPERELASTIC ALLOY
Brain activity estimation device
This is a divisional of U.S. patent application Ser. No. 10/580,127 filed on May 19, 2006, which is a national phase application of PCT/JP2004/017161 filed on Nov. 18, 2004, which claims priority of JP 2003-390483 filed on Nov. 20, 2003.
The present invention has been made in order to solve the above mentioned problem. According to the present invention, there is provided a crawler belt comprising an endless high-tensile-strength belt (21) and a belt main body (22) made of elastic material and attached to an outer periphery of the high-tensile-strength belt, the high-tensile-strength belt (21) having engagement holes (21a) arranged at even intervals in a circumferential direction thereof, the belt main body (22) having escape recesses (23a) formed at locations corresponding to the engagement holes of the high-tensile-strength belt.
the crawler belt (20) comprises an endless high-tensile-strength belt (21) and a belt main body (22) made of elastic material and attached to an outer periphery of the high-tensile-strength belt, the high-tensile-strength belt (21) having engagement holes (21a) arranged at even intervals in a circumferential direction thereof, the belt main body having escape recesses (23a) formed at locations corresponding to the engagement holes of the high-tensile-strength belt, and wherein
a driving wheel of the plurality of wheels (10) has engagement projections (12a) arranged at even intervals in a circumferential direction on an outer peripheral surface thereof, the engagement projections (12a) being adapted to be engaged with the engagement holes (21a) of the high-tensile-strength belt (21) of the crawler belt (20) and at the same time to enter the escape recesses (23a) of the belt main body (22).
Preferably, outer peripheral surfaces of the plurality of wheels (10) are generally cylindrical surfaces. More preferably, the engagement holes (21a) of the high-tensile-strength belt (21) have a generally circular shape and the engagement projections (12a) of the wheel (10) have a generally semi-spherical shape. This contributes to the reduction of noise.
preparing a first mold (70) having a plurality of mold projections (74a) arranged at even intervals on a molding surface thereof and a second mold (80) having a plurality of lug mold recesses (86) opening at a molding surface thereof;
setting en endless high-tensile-strength belt (21) having engagement holes (21a) arranged at even intervals in a circumferential direction thereof on the first mold (70) by fitting the mold projections (74a) into the engagement holes; and
molding an elastic material between the first mold and the second mold to obtain a belt main body (22) or a part (22′) of the belt main body (22) attached to an outer periphery of at least a part of the high-tensile-strength belt, at the same time forming escape recesses (23a) by allowing the molding projections (74a) of the first mold (70) to press into the elastic material and forming tread lugs (26) by allowing the elastic material to enter the lug mold recesses (86) of the second mold (80).
preparing a lower mold (70) having a plurality of mold projections (74a) arranged at even intervals on an upper surface thereof and an upper mold (80) having a plurality of lug mold recesses (86) opening at an lower surface thereof;
positioning an endless high-tensile-strength belt (21) having engagement holes (21a) arranged at even intervals in a circumferential direction thereof by placing a part of the high-tensile-strength belt (21) on the lower mold (70) and by fitting the mold projections (74a) of the lower mold into the engagement holes of the high-tensile-strength belt;
placing an elastic material on said lower mold and lowering said upper mold to mold a part (22′) of a belt main body (22) on an outer periphery of the high-tensile-strength belt (21) between the upper mold and the lower mold, at the same time forming escape recesses (23a) by allowing the mold projections (74a) of the lower mold (70) to press into the elastic material, and forming tread lugs (26) by allowing the elastic material to enter the lug mold recesses (86) of the upper mold (80); and
Preferably, mold pins (74) are removably inserted into the upper surface of the lower mold (70) and head parts of the mold pins are provided as the mold projections (74a). By this, after molding, the molded part of the belt main body and the high-tensile-strength belt can be removed from the lower mold without substantial resistance, which contributes to significantly improve productivity.
As shown in FIGS. 1 and 2, each of the crawler units 2 comprises wheels 10 in the front and rear, an endless crawler belt 20 trained about the wheels 10 and a pair of side plates 30 rotatably supporting the wheels 10 in the front and rear. The side plate 30 of each of crawler units 2 located on an inner side is attached to the mounting base 1 at the central portion of the side plate 30.
As shown in FIGS. 2 and 4, outer peripheral surface of the each of the wheels 10 is a cylindrical surface. The wheel 10 has semi-spherical engagement projections 12a arranged at even intervals in a circumferential direction at a center in a width direction of the outer peripheral surface thereof. In this embodiment, a diameter of the engagement projection 12a is around 3 millimeters while a width of the wheel 10 is 30 millimeters.
As shown in FIG. 4, the peripheral edge of the side plate 30 has a tapered cross section all around the periphery and its outer face is an inclined surface 30c.
The steel belt 21 is constructed by welding opposite ends of an elongated thin belt of a thickness of from 0.05 to 1.0 millimeters (0.15 millimeters in this embodiment). A width of the steel belt 21 is generally same as that of the wheel 10. The steel belt 21 has circular engagement holes 21a arranged at even intervals (the same interval as that of the engagement projections 12a of the wheel 10) in a circumferential direction at a center in the width direction thereof. A diameter of the engagement holes 21a is the same as or a slightly greater than that of the engagement projections 12a.
As shown in FIGS. 1 and 3, the belt main body 22 integrally includes an endless base part 23 of a width greater than that of the steel belt 21, a shielding brim 24 formed on opposite sides in a width direction of the base part 23 and tread lugs 26 spacedly formed on an outer periphery of the base part 23. The base part 23 has generally semi-spherical escape recesses 23a arranged at center in the width direction thereof, at locations corresponding to the engagement holes 21a of the steel belt 21 to communicate with the engagement halls 21a.
The crawler belt 20 is placed around half of the periphery of the wheels 10 in the front and rear. As shown in FIG. 4, in an area covering half of the periphery of the wheel 10, the steel belt 21 contacts the outer peripheral surface of the wheel 10 directly, the engagement projections 12a of the wheel 10 engaging the engagement holes 21a of the steel belt 21 and at the same time entering the escape recesses 23a of the base part 23.
The crawler belt 20 can be surely prevented from coming off the wheel 10 in a left and right direction since the projections 12a of the wheel 10 fit into the engagement holes 21a of the steel belt 21.
The shielding brim 24 of the belt main body 22 contacts the inclined surface 30c of the side plate 30 at the peripheral edge of the side plate 30 with the shielding brim being elastically deformed. As a result, an inner space surrounded by the crawler belt 20 and the pair of side plates 30 is sealed, thereby preventing foreign substances such as water, sands and dust from entering into the inner space.
The lower mold 70 includes a base section 71 and a molding section 72 having an inverted U-shaped cross-section, which are detachable from each other. The lower mold 70 has a hollow rectangular parallelepiped shape with both ends open. As shown in FIG. 9, the molding section 72 has receiving holes 72a arranged at even intervals in a longitudinal direction on an upper surface thereof. Mold pins 74 are removably received in the receiving holes 72. The mold pin 74 includes a head portion having a semi-spherical shape and being provided as a mold projection 74a. A pair of linear auxiliary mold recesses 73 for molding the shielding brim 24 are formed sandwiching a row of the mold projections 74a on the lower mold 70.
The steel belt 21 is passed through the hollow lower mold 70 and a part of the steel belt 21 is placed on the upper surface of the lower mold 70. At that time, the mold projections 74a of the lower mold 70 are fitted into the engagement holes 21a of the steel belt 21, thereby positioning the steel belt 21.
At the time of the molding, a part of the base part 23 is molded with the mold recess 81, a part of the shielding brim 24 is molded with the auxiliary mold recess 73, the escape recess 23 is molded by allowing the mold projection 74a to press into the rubber material and the tread lug 26 is molded by allowing the rubber material to enter the lug mold recess 86. A part of the rubber material protruded from an upper opening of the lug mold recess 86 is removed with a spatula, etc.
After the molding is done as described above, the upper mold 80 is lifted. Then as shown in FIG. 10, the steel belt 21 is peeled off the lower mold 70. Since the molding of the rubber as described above involves contraction, the mold projection 74a is attached strongly to the rubber, and therefore the mold pin 74 is removed from the lower mold 70 together with the steel belt 21 and the part 22′ of the belt main body 22.
Next, the mold pin 74 is removed from the steel belt 21 and the part 22′ of the belt main body 22 as shown in FIG. 11. Since the mold pin 74 is separate from the lower mold 70, the mold pin 74 can be easily detached from the escape recess 23a of the part 22′. The productivity is improved compared to a case where mold projections are integrally formed with the lower mold.
Other embodiments of the present invention are described below referring to FIGS. 12 to 17. Same numbers are used for the components corresponding to those of the first embodiment and a detailed description thereof is omitted.
A third embodiment as shown in FIG. 13 is identical to the second embodiment except the following: the steel belt 21 is embedded in the base part 23 of the belt main body 22 and a thin rubber layer 29 is formed on an inner periphery of the steel belt 21. The rubber layer 29 has an inner peripheral surface corresponding to the outer peripheral surface of the wheel 10. When the wheel 10 is made of metal, the rubber layer 29 serves to prevent abrasion caused by metal-to-metal contact between the steel belt 21 and the wheel 10.
In a fourth embodiment as shown in FIGS. 14 to 16, the wheel 10 is made of resin, etc. and its outer peripheral surface is a cylindrical surface. Engagement pins 12 made of metal are embedded and arranged at even intervals in a circumferential direction at a center in the width direction of the outer peripheral surface of the wheel 10. A head part of the engagement pin 12 having a semi-spherical shape projects from the outer peripheral surface of the wheel 10 and is provided as an engagement projection 12a.
As shown in FIG. 16, the side plate 30 comprises a metal plate 31 and a pair of seal members 32. As shown in FIG. 15, the metal plate 31 has a front and rear end edges 31a, each having a semi-circular shape corresponding to a shape of a peripheral edge of the front and rear wheels 10, respectively. The front and rear end edges 31a are, as shown in FIG. 15, cut away from inside to be reduced in thickness.
As shown in FIG. 16, the seal member 32 is detachably attached to an upper and lower parts of the peripheral edges of the metal plate 31, the upper and lower parts having a linear shape. To be more specific, the seal member 32 is made of rubber material having smaller elastic coefficient than the belt main body 22 of the crawler belt 20 to be described later. The seal member 32 is attached to a bracket 33 having a linear shape with a L-shaped cross section by vulcanization bonding, etc. and the bracket 33 is removably fixed to upper and lower parts of the peripheral edge of the side plate 30 with a screw 34. The seal member 32 includes a thin raised wall 32a.
In the part of the crawler belt 20 which is placed around the wheels 10 in the front and rear, the edge of the shielding brim 24 contacts the end edges 31a in the front and rear of the side plate 30. In the other part of the crawler belt 20 which is placed between the wheels 10 in the front and rear, the edge of the shielding brim 24′ contacts the raised wall 32a of the seal member 32. As a result, the inner space surrounded by the crawler belt 20 and the pair of side plates 30 is sealed, thereby preventing foreign substances such as water, sands and dust from entering into the inner space.
In the part of the crawler belt 20 which is placed around half of the periphery of the wheels 10, the crawler belt 20 is bent, and therefore, the shielding brim 24′ is warped away from the end edge 31a of the side plate 30. But the edge of the shielding brim 24′ can contact the end edge 31a securely despite the warping because the edge of the shielding brim 24′ is elastically deformed as it contacts the end edge 31a of the side plate 30. When the shielding brim 24′ of the crawler belt 20 contacts the seal member 32 at the upper and lower parts of the peripheral edge of the side plate 30, the seal member 32 is deformed more greatly than the shielding brim 24′ because the seal member 32 has smaller elastic coefficient and is thinner than the shielding brim 24′. This permits the seal member 32 and the shielding brim 24′ to be maintained in contact with each other even when the crawler belt 20 flaps in an area not restrained by the wheels 10 because the seal member 32 is deformed following the flapping of the belt 20. The seal member 32 is coated with Teflon®, etc., which serves to reduce friction between the seal member 32 and the shielding brim 24′.
The lower mold 70 and the upper mold 80 as shown in FIG. 17 are used to mold the crawler belt 20 according to the fourth embodiment of the present invention. In this embodiment, a pair of auxiliary mold recesses 82 having a linear shape are formed along opposite sides of the mold recess 81 of the upper mold 80. The auxiliary mold recess 82 has a cross-section corresponding to the shield brim 24′. The molds 70 and 80 are used in the same manner as in the first embodiment as described above.
FIG. 1 is a perspective view of a crawler structure of a robot having a pair of left and right crawler units according to a first embodiment of the present invention.
FIG. 2 is a side view of the crawler unit.
FIG. 3 is a longitudinal sectional view of a crawler belt used in the crawler unit with a thickness of a steel belt exaggerated.
FIG. 4 is a longitudinal sectional view of the crawler belt in a state of being placed around a wheel.
FIG. 5 is a side view of the crawler belt.
FIG. 6 is a plan view of the crawler belt.
FIG. 7 is a schematic view of tread lugs of the crawler belt as they are gripping rubble.
FIG. 8 is a perspective view of equipment used for manufacturing the crawler belt.
FIG. 9 is an enlarged longitudinal view of a main part of the equipment showing a belt main body of the crawler belt being molded.
FIG. 10 is an enlarged longitudinal view of a main part of the equipment showing a molded part of the belt main body and the steel belt being removed from a lower mold.
FIG. 11 is an enlarged longitudinal view of a main part of the equipment showing a mold pin being removed form a molded part of the belt main body and the steel belt.
FIG. 12 is a longitudinal sectional view of a crawler unit according to a second embodiment of the present invention.
FIG. 13 is a longitudinal sectional view of a crawler unit according to a third embodiment of the present invention.
FIG. 14 is an enlarged longitudinal sectional view of a crawler belt according to a fourth embodiment of the present invention.
FIG. 15 is a longitudinal sectional view showing a seal structure between the crawler belt and an end edge of a side plate according to the fourth embodiment of the present invention.
FIG. 16 is a longitudinal sectional view showing a seal structure between the crawler belt and a middle part of the side plate according to the fourth embodiment of the present invention.
FIG. 17 is a perspective view of equipment used for manufacturing the crawler belt according to the fourth embodiment of the present invention.
12a engagement projection
74a mold projection
preparing a first mold having a plurality of mold projections arranged at even intervals on a molding surface thereof and a second mold having a plurality of lug mold recesses opening at a molding surface thereof;
setting an endless high-tensile-strength belt having engagement holes arranged at even intervals in a circumferential direction thereof on said first mold with said mold projections fitted into said engagement holes; and
molding an elastic material between said first mold and said second mold to obtain a belt main body or a part of said belt main body attached to an outer periphery of at least a part of said high-tensile-strength belt, at the same time forming escape recesses by allowing said molding projections of said first mold to press into said elastic material and forming tread lugs by allowing said elastic material to enter said lug mold recesses of said second mold.
preparing a lower mold having a plurality of mold projections arranged at even intervals on an upper surface thereof and an upper mold having a plurality of lug mold recesses opening at an lower surface thereof;
positioning an endless high-tensile-strength belt having engagement holes arranged at even intervals in a circumferential direction thereof by placing a part of said high-tensile-strength belt on said lower mold and by fitting said mold projections of said lower mold into said engagement holes of said high-tensile-strength belt;
placing an elastic material on said lower mold and lowering said upper mold to mold a part of a belt main body on an outer periphery of said high-tensile-strength belt between said upper mold and said lower mold, at the same time forming escape recesses by allowing said mold projections of said lower mold to press into said elastic material and forming tread lugs by allowing said elastic material to enter said lug mold recesses of said upper mold; and
molding said endless belt main body all around the periphery of said high-tensile-strength belt by moving said high-tensile-strength belt to place a new part of said high-tensile-strength belt on said lower mold, said new part adjoining said part where said part of said belt main body was molded, molding another part of said belt main body on said new part of said high-tensile-strength belt in the foregoing way, and by repeating the procedure.
9. A method for manufacturing a crawler belt according to claim 8, wherein mold pins are removably inserted into said upper surface of said lower mold and head parts of said mold pins are provided as said mold projections.
Patent Grant number: 8658073
Applicants: TOKYO INSTITUTE OF TECHNOLOGY (Tokyo), TOPY KOGYO KABUSHIKI KAISHA (Tokyo)
Inventors: Shigeo Hirose (Tokyo), Shingo Tsukui (Toyohashi-shi)
Application Number: 12/491,054
Current U.S. Class: Positioning Or Maintaining Position Of Preform Relative To Mold Surface (264/275)
International Classification: B29C 41/28 (20060101);