1 2
task. More importantly, once a pole of proper length
DEVICE CAPABLE OF POSITIVE EXTENSION has been assembled, it continues to suffer from the dis
AND RETRACTION USING A CASADING FORCE advantage described above relating to the limitation on
TRANSFER the length of the stroke.
5 A possible solution is to form a pole made up of a
FIELD AND BACKGROUND OF THE number of interconnected members which are able to
INVENTION move relative to one another and thereby alternately
The present invention relates to a device which is lengthen and shorten the pole. Such a pole may use
useful for efficiently extending and retracting a wide hydraulic or pneumatic means, not unlike those used in
variety of tools and, more particularly, to a device made 10 a variety of winches, for example, the system used to
up of a plurality of interacting members which can be position a basket carrying an electrical repairman suffi
easily extended and retracted so as to place in the de- ciently near a transformer as to allow the repairman to
sired location a tool or other instrumentality attached to work on the transformer. However, such systems are
the device. heavy and mechanically complicated and are thus not
It is often desirable to be able to place and cause to 15 suitable for a simple hand-held pole for use in properly
operate a tool or other instrumentality (hereinafter locating a relatively light tool.
"tool") at a location which is more distant than can be There is thus a widely recognized need for, and it comfortably be reached by extending one's arm with would be highly advantageous to have, an extendiblethe tool therein. For example, when one wishes to retractable device which can be actively and positively change an incandescent light bulb located in a ceiling 20 extended and retracted, as desired by the user, with the which is ten feet tall, it is necessary to grab and rotate device oriented at any angle, to which a tool could be the light bulb. To this end one might climb on a ladder attached and which could be easily used to rapidly vary and use one's hand to replace the bulb. Alternatively, the length of the ^ during the performance Qf a parone could obviate the need to use a ladder by using a ticular task sufficiently long pole which had a tool at its end .which 25
was capable of grabbing and rotating the bulb. In this SUMMARY OF THE INVENTION
case, the operator would remain standing safely on the According to the present invention there is provided
ground while replacing the light bulb and would carry ^ extendible-retractable device, comprising: (a) a first
outthe operation through the use of the long pole memb ^ & ... the
While a pole as described is useful m certain appl.ca- 30 m
tion, it is not free from shortcomings. Primarily, it is . . '>' .. . c , „
known that, unlike the case of replacing a light bulb P°stenor P?*10* of the second member, the first flexi
described above, in many operations the location at blf sector **mg constrained by and being movable
which the operation is to take place is not at a fixed relative to » location of the first member; and (d) a
distance from the user but varies either discretely or 35 f^oad flexible connector attached to a posterior por
continually during the operation. tlon of the second member, the second flexible connec
For example, if one wished to paint the ten-foot tall tor bem8 constrained by and being movable relative to
walls and the ceiling of a room with a paint roller, a second location of the first member, the second loca
means must be at hand for locating the roller at every tlon bemg posterior of the first location, the first flexible
point on the walls and ceiling. Furthermore, the loca- 40 connector and the second flexible connector being cou
tion of the roller varies instantaneously during each Pled t0 each other so that the first flexible connector,
painting stroke, regardless of the position of the painter. the second flexible connector and the second member
One option is to use a hand-held roller and make use of 311 move simultaneously.
a ladder or scaffolding to reach the top portions of the According to further features in preferred embodi
walls and the ceiling. Another alternative is to mount 45 ments of the invention described below, there is further
the roller on a sufficiently long pole which will allow provided: (e) a third member movable relative to the
the top portions of the walls and the ceiling to be first member and the second member; (f) a third flexible
reached with the painter remaining standing on the connector attached to a posterior portion of the third
floor without requiring the use of a ladder. member, the third flexible connector being constrained
One disadvantage of this technique is that the length 50 by and being movable relative to a first location of the of a stroke is limited by the distance through which the second member, the third flexible connector being atpainter's arms can move, i.e., if the painter is able to tached to a first attachment location of the first member translate the pole a distance of three feet, the paint so that anteriorly-directed motion of the second memstroke on the wall will be limited to three feet. ber results in anteriorly-directed motion of the third
A further disadvantage of this technique is that the 55 member; and (g) a fourth flexible connector attached to
pole is of fixed length and may therefore be of limited a posterior portion of the third member, the fourth
use in other applications. Thus, a five foot pole which flexible connector being constrained by and being mov
may be useful in painting a room having ten-foot high able relative to a second location of the second member,
walls and ceiling, may be largely inadequate in painting the second location being posterior of the first location,
a room having fifteen-foot high walls and ceiling. 60 the fourth flexible connector being attached to a second
To partially overcome the latter disadvantage and to attachment location of the first member so that posteri
thereby increase its versatility, it is possible to form the orly-directed motion of the second member results in
pole from a number of detachable modules. In this way posteriorly-directed motion of the third member,
modules could be added or removed before each use so According to still further features in the described
as to produce a pole with overall length which is ade- 65 preferred embodiments the members are nested to
quate for the intended task. While the modularization of gether and are approximately cylindrical in shape, al
the pole overcomes certain difficulties, it remains a though the members may not be nested but rather may
tedious chore to add or remove modules before each be arranged next to each other.
