Conveyors: power-driven – Conveyor or accessory therefor specialized to convey people – By stairway having steps forming an endless member
Reexamination Certificate
1999-10-20
2001-06-05
Valenza, Joseph E. (Department: 3651)
Conveyors: power-driven
Conveyor or accessory therefor specialized to convey people
By stairway having steps forming an endless member
Reexamination Certificate
active
06241071
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a tread unit on which persons step for passenger conveyor systems such as escalators and moving walks. More particularly, the invention relates to a tread unit of a passenger conveyor, which is made of fiber reinforced plastic, and to a passenger conveyor system constructed by coupling a plurality of such tread units.
BACKGROUND ART
Aluminum die castings and steels are generally used as materials for each member of a tread and a riser that constitute a tread unit of a passenger conveyor such as an escalator. In recent years, tread units using fiber reinforced plastic (FRP) have also been proposed.
FIG. 13
shows a conventional tread unit of an escalator disclosed in Japanese Patent Application Laid-open No. Hei 7-330266, and
FIG. 14
shows a tread unit of an escalator disclosed in WO 95/23758 using fiber reinforced plastic. In
FIG. 13
, reference numeral
101
denotes a tread,
102
denotes a reinforcing rib,
103
denotes a riser, and
106
denotes a bracket. This tread unit is made solely of aluminum die castings. Further, in
FIG. 14
, reference numerals
102
a
and
102
b
denote reinforcing ribs. This tread unit is made solely of fiber reinforced plastic.
Also, in Japanese Utility Model Application Laid-open No. Hei 6-8372, a sectional view of a tread of a passenger conveyor is shown and it discloses that the surface of the tread is provided with a film made of quartz sand thereby facilitating and reducing costs of non-slip processing. Further, in Japanese Patent Application Laid-open No. Sho 63-139808, it is disclosed that steel wires and rubber belts reinforced by woven fabrics are used as a conveying body.
As described above, most of the conventional tread units of passenger conveyors such as escalators are made of aluminum die castings, with some made of steel. In the case of using aluminum die castings, reinforcing members made of steel are arranged at the lower portion of the tread in order to ensure a prescribed rigidity. Accordingly, weight of the tread unit is increased, and from this arises problems such that the size of the escalator drive unit and the braking force are increased. Furthermore, conventional tread units have another problem in regards to the wear resistance treatment given to the surface of their treads. Since the surface of aluminum die castings provides only poor bond, flaking results, and this leads to defects in reliability and the aesthetic design of the tread unit. Further, in the fiber reinforced plastic proposed in
FIG. 14
, since short fibers that are several centimeters long or so are used as reinforcement, rigidity and strength are not adequate, and thus an extremely complicated reinforcing rib structure is required at the lower portion of the tread. From this arises still other problems in that structural defects easily occur due to poor wetting of resins, nonuniform distribution of reinforcement and the inclusion of voids and the like during the molding process at the time of manufacture, and the weight of the unit is increased. Also, these problems have caused increased production costs as well. Further, for conveyor belts used for conveying people, the cleats of the tread are only made of rubber, and thus their rigidity is low. As a result, people do not ride stably on such belts.
The present invention has been made to overcome the aforementioned problems. Therefore, an object of the present invention is to obtain a tread unit made of fiber reinforced plastics (hereinafter referred to as an “FRP tread unit”) and a passenger conveyor system using such an FRP tread unit, which ensures adequate rigidity and strength using reinforcements made of continuous long fibers, which allows a highly reliable surface treatment to be given, and in which diversified aesthetic designs and reductions in weight can be implemented.
DISCLOSURE OF THE INVENTION
According to a first aspect of the present invention, there is provided a tread unit of a passenger conveyor comprising: a tread portion onto which load is applied and which has a cleat portion on an obverse surface thereof; a reinforcing portion provided on a reverse surface of the tread for reinforcing the tread; and a riser portion having a cleat portion on a front surface thereof and being formed so as to project downward from one end of the tread portion, wherein at least one of the tread portion and the riser portion is made of fiber reinforced plastic which is reinforced by a reinforcement made of knitted continuous long fibers. According to this construction, a three dimensional knitted fabric, a hollow woven fabric, or a multi-axial braid is used as a molding substrate, and thus the reinforcement made of a continuous long fiber can be oriented efficiently in any direction. Hence, a tread unit can be designed with the specific rigidity and specific strength of the whole unit adequately improved.
According to a second aspect of the present invention, in the tread unit of the first aspect of the invention, at least one of the tread portion and the riser portion is made of fiber reinforced plastic which is reinforced by a reinforcement made of continuous long fibers knitted in three dimensions in accordance with a pitch of the cleat portion. According to this construction, a tread unit can be designed with the specific rigidity and specific strength of the whole unit adequately improved.
According to a third aspect of the present invention, in the tread unit of the first aspect of the invention, the cleat portion of the tread portion or the riser portion is provided with wear resistant means and friction characteristic control means. According to this construction, the surface of the reinforced fiber is provided with a surface treated layer in which wear resistance and coefficient of friction are controlled, and thus there will be no impairment of the aesthetic design due to flaking.
According to a fourth aspect of the present invention, in the tread unit of the first aspect of the invention, the reinforcing portion is made of resin which is reinforced by a reinforcement made of a plurality of continuous long fibers. According to this construction, the reinforcing portion can be made light, and its strength can be improved easily.
According to a fifth aspect of the present invention, in the tread unit of the fourth aspect of the invention, a matrix resin of the reinforcement of the reinforcing portion is an elastic body. According to this construction, a stable ride will be provided.
According to a sixth aspect of the present invention, in the tread unit of the fourth aspect of the invention, the reinforcing portion is further provided with noise insulation means. According to this construction, a tread unit having high noise insulation effect can be provided easily.
According to a seventh aspect of the present invention, in the tread unit of the fourth aspect of the invention, at least two of the tread portion, the reinforcing portion and the riser portion which are constructed of fiber reinforced materials are sutured together with fibers. According to this construction, a tread unit can be manufactured easily.
According to an eighth aspect of the present invention, in the tread unit of the first or the fourth aspect of the invention, the fibers of the reinforcement or thematrix resin of the fiber reinforced plastic are colored. According to this construction, a desired indication and expression can be given to a tread unit.
A passenger conveyor system of the present invention comprises a plurality of the tread units of a passenger conveyor as recited in any one of the first to eighth aspects, the tread units being coupled to one another. According to this construction, the weight of the whole system can be reduced, and its aesthetic design can be improved.
REFERENCES:
patent: 2085076 (1937-06-01), Dunlop
patent: 2152795 (1939-04-01), Dunlop
patent: 2214580 (1940-09-01), Dunlop
patent: 5350049 (1994-09-01), Ahls et al.
patent: 5358089 (1994-10-01), Riedel
patent: 6039167 (2000-03-01), Vellinga
patent: 60-151881 (1985-10-01), None
paten
Haruta Yasumasa
Hiroshima Noboru
Honda Toshihisa
Murayama Kunihiko
Noshita Akira
Leydig , Voit & Mayer, Ltd.
Mitsubishi Denki & Kabushiki Kaisha
Valenza Joseph E.
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