Illumination – Self powered lamp – Generator power source
Reexamination Certificate
1999-04-29
2001-08-21
Husar, Stephen (Department: 2875)
Illumination
Self powered lamp
Generator power source
C362S431000, C362S403000, C362S385000, C362S414000, C362S259000, C362S238000, C362S233000, C362S171000
Reexamination Certificate
active
06276811
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a projector mainly used as illumination of road construction or the like in the nighttime, particularly to a telescopic structure of a telescopic post (hereinafter, may simply be referred to as “post”) erected on a carriage.
2. Description of the Prior Art
Conventionally, there has been known a projector in which a telescopic post is erected on a carriage mounted with a generator and a required number of illumination devices are mounted at an upper portion of the telescopic post (for example, refer to JP-A-7-331926).
Further, there is generally known a telescopic post constituting a projector of this kind. As shown by, for example,
FIG. 9
in which a base pipe post
100
fixed vertically on an upper face of a carriage, not illustrated, is successively inserted with ascendably and descendably a plurality of middle pipe posts
101
and
102
having inner diameters successively reduced relative to the base pipe post, a first pulley
103
is attached to an upper portion of an inner face of the base pipe post
100
, a second pulley
104
is attached to an upper portion of an inner face of the middle pipe post
101
at a lower stage, respectively, the first pulley
103
is hung with a first wire
105
one end of which is connected to a lower portion of the middle pipe post
101
at the lower stage and other end of which is fixed to a hoisting drum of a winch
107
whereas the second pulley
104
is hung with a second wire
106
one end of which is fixed to a lower portion of the middle pipe post
102
at an upper stage and other end of which is fixed to an upper portion of the base pipe post
100
.
According to the telescopic post, the middle pipe posts
101
and
102
are ascended to extend by reeling in the wire
105
by manually or electrically turning the winch
107
whereas the middle pipe posts
101
and
102
are descended to contract by reeling out the wire
105
by which the height of the illumination devices attached at an upper end of the middle pipe post
102
can pertinently be adjusted.
However, according to the projector using the telescopic post, all of weight of the middle pipe posts
101
and
102
as well as the illumination devices attached to the upper end, attachment metal pieces thereof and so on is exerted on the wire
105
reeled by the winch
107
and when, for example, the illumination devices are two lamps, the total load exceeds 10 kg. Hence, normally, a force required for reeling operation is alleviated by a speed reducing mechanism built in the winch
107
, however, on the other side, there poses a problem in which the extracting and retracting speed of the post is retarded.
Further, in order to reduce the load, it is conceivable to make the respective middle pipe posts
101
and
102
slender and provide vertical grooves slidable by the pulleys
103
and
104
at the side faces of the pipe posts
101
and
102
. However, in that case, there is a concern of deteriorating the strength of the post. Further, the vertical grooves are exposed in a state where the post is extended and accordingly, not only the outlook is deteriorated but also rain water, dust or the like is liable to invade the inside of the post which gives rise to a concern of causing failure or contamination.
In the meantime, the applicant has previously proposed a telescopic post using a gas damper in place of a winch, mentioned above, in order to considerably promote an operability in extracting and retracting the telescopic post, mentioned above (refer to JP-A-8-184217).
According to the telescopic post, as shown by
FIG. 8
, a base pipe post
110
is inserted successively ascendably and descendably with a plurality of, in this case, two of middle pipe posts
111
and
112
at a lower stage and at an upper stage having inner diameters successively reduced relative to the base pipe post
110
, a gas damper
114
is built in the base pipe post
110
such that a side of extracting and retracting a rod
113
is directed downwardly, the gas damper
114
is erected at inside of the base pipe post
110
by fixing a rod tip portion
115
to an inner bottom portion of the base pipe post
110
and a first pulley
116
is installed above the gas damper
114
. The first pulley
116
is hung with a first wire
117
one end of which is fixed to a lower portion of the base pipe post
110
and other end of which is fixed to a lower portion of the middle pipe post
111
at the lower stage, whereas a second pulley
118
is arranged at an upper inner portion of the middle pipe post
111
at the lower stage and the second pulley
118
is hung with a second wire
119
one end of which is fixed to a lower portion of the middle pipe post
112
at the upper stage and other end of which is fixed to a lower portion of the base pipe post
110
.
According to the telescopic post, elastic force of the gas damper
114
in a contracted state is set to be substantially equal to load applied on the first pulley
116
in the telescopic post in a contracted state. By operating upwardly and downwardly a handle
120
installed at the middle pipe post
111
the post can be extended and contracted swiftly by utilizing the elastic force of the gas damper
114
without carrying out operation of reeling in and reeling out the wires. Further, the operation for extending and contracting the post can be carried out by small force utilizing effectively the spring force of the gas damper.
According to the telescopic post described above, in addition to the fact that the plurality of middle pipe posts can be moved upwardly and downwardly by utilizing the spring force of the gas damper, by containing the gas damper and the pulleys at hollow inner portions of the respective pipe posts, the respective pipe posts are made slender without providing notches and the weight can be reduced while ensuring the strength of the post. As a result, there is achieved an advantage in which extraction and retraction of the post can swiftly be carried out by simple moving up and down operation. Further, there is achieved a significant effect in which the outlook is excellent and there is no concern of invading of rain water, dust or the like to inside of the post since the ascending mechanism is not exposed to outside. However, there remain a few points of improvement in dealing with a mode of use shown below.
That is, according to the conventional gas damper type telescopic post, in the contracted state, the load applied on the gas damper and the elastic force of the gas damper are balanced, the balance is collapsed by moving up the handle
120
by an operator, the post is extended by the elastic force of the gas damper and the post is contracted by moving down the handle
120
against the elastic force. However, when a telescopic post having a multiple stage structure of four stages or more is formed in order to install the illumination devices at a higher location, the extending and contracting operation by moving up and down the handle
120
becomes difficult.
Further, according to the telescopic post having the multiple stage structure, a gas damper having a larger stroke is used and accordingly, sufficient consideration is needed in view of safety.
SUMMARY OF THE INVENTION
The present invention has been carried out in view of the above-described conventional situation and it is an object of the present invention to provide a telescopic post which can extremely easily deal with a multiple stage structure, can set an illumination device at a higher location, can give sufficient consideration also in safety and excellent in operability in addition to effects provided by the conventional gas damper type telescopic post proposed by the applicant.
In order to achieve the above-described problem, according to a first feature of the present invention, there is provided a projector in which a telescopic post having a required number of illumination devices is erected on a carriage and the telescopic post is formed such that at least one middle pipe post having a succe
Taguchi Masayuki
Yoshimori Tokujin
Alavi Ali
Darby & Darby
Green Service Co., Ltd.
Husar Stephen
LandOfFree
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