1. Field of the Invention
The subject invention relates to oscillography and oscillographs and other recording methods and recorders, to methods and apparatus for supplying wound material from rolls of diminishing diameter and other winding and reeling methods and apparatus, to methods and apparatus for releasably retaining any one of several tubular objects of different lengths, and to combinations of such methods and apparatus.
2. Description of the Prior Art
An advanced type of record medium transport mechanism is disclosed in U.S. Pat. No. 3,216,021. That apparatus appears able to handle reporting medium strips wound on a supply roll and having an information recording surface layer either facing inwardly or outwardly on the supply roll. Also, that apparatus appears capable of winding the recording medium strip, after recordation thereon, on a takeup roller, or then of discharging such recording medium strip from the machine. To this end, that prior-art apparatus has a drive roller with gearing shiftable between different positions, as well as a shiftable front door with roller mount bearings and shiftable takeup roller.
This tends to introduce complexities and limitations in practice. Also, the supply roll in that type of apparatus may unwind too quickly or non-uniformly as a function of diminishing supply roll diameter.
Also, that type of apparatus requires the recording material to be disposed on core with laterally projecting shafts on the supply and takeup sides.
U.S. Pat. Nos. 1,531,705, 3,360,210, 3,497,152 and 3,539,126 propose various winding devices and similar apparatus in which rolls are geared together or mutually engaged to rotate in unison. In practice, such systems often are difficult to realize or are subject to design limitations.
In the prior-art equipment under consideration, there also exists a need for more convenient and effective supply roll mounting systems for accommodating supply rolls located on tubular supports of different lengths.
In more general terms, there exists a need for methods and apparatus for releasably retaining any one of several tubular objects of different lengths.
In this respect, an early proposal according to U.S. Pat. No. 1,683,876 employs conical cable drum retaining members which are rotatably mounted on a pair of spaced standards. In practice, there existed the drawback that at least an entire standard had to be moved to accommodate cable drums of different widths. To somewhat alleviate this problem, the proposal according to U.S. Pat. No. 3,955,770 mounts the coil-supporting assemblies on tracks for sliding movement toward and away from each other. The proposal according to U.S. Pat. No. 1,702,971 employs flat paddles for supporting bolts of cloth preparatory to and during unwinding operations. One of the paddles is rotatably mounted on a standard which, together with a tubular track extending parallel to an axis through the paddles, is attached to the floor. The other paddle is rotatably mounted on a standard which, in turn, is supported on a tubular carriage riding in the mentioned tubular track. A spring has opposite ends attached to, and extends through the tubular track and carriage; biasing the carriage into the tubular track. A locking device arrests the motion of the carriage relative to the tubular track at any one of several incremental positions in order to permit an accommodation of bolts of cloth of different widths. In so arresting the motion of the carriage, the locking device also renders the mentioned spring ineffective from exercising a biasing function on the cloth retaining paddles.
In practice, the latter drawback coupled with an only step-wise adjustability of the distance between the paddles would render that prior-art system unsuitable for releasably retaining tubular members or supply rolls of different lengths.
An infinitely adjustable spacing between supply roll retention members appears possible in the system disclosed in U.S. Pat. No. 3,104,073. However, the use of a tool and the carrying out of set screw releasing and tightening operations are then required for each change in supply roll width.
A later proposal according to U.S. Pat. No. 3,941,320 appears only suitable for clamping tubular supply roll supports of a given length.
A proposal according to U.S. Pat. No. 3,792,825 uses spring clamps acting on the outside of a supply roll for retaining same in a chart drive system. That principle appears to be rather limited to the handling of perforated paper rolls. The latter patent also proposes the use of pads as braking devices. Again, there appears to be a design limitation to particular chart roll materials.
A more universally applicable tension regulator has been proposed in U.S. Pat. No. 1,676,797 wherein a roller rests on the outside of the supply roll to sense its diminishing diameter during unwinding of the material from the supply roll. That sensing roller is rotatably mounted in an arm which is spring biased to maintain the sensing roller in contact with the supply roll. That arm also transmits the motion of the sensing roller along a circular trajectory through the axis of rotation of the supply roll to a friction head or button that rides on a circular friction surface rotating with the supply roll.
The subsequent U.S. Pat. No. 3,720,385 alludes to drawbacks in the latter prior-art tensioning system and, in turn, proposes to do away with the need for a spring bias of the roll diameter sensor by placing cylindrical sensing means as well as corresponding brake means at loci beyond points of tangency between a circle of a diameter of the effective braking disk diameter and a tanential line passing through the pivot point of follower arms to which the sensing and braking means are attached.
In practice, the latter proposal, in turn, has the drawback of operating only in one sense of rotation of the supply roll. This is a particular disadvantage if supply rolls containing a recording material having an information recording surface layer facing inwardly and supply rolls containing a recording medium having a recording surface layer facing outwardly are to be employed alternatively in the particular system. Moreover, the sensing rolls or cylindrical members of prior-art tension regulators often have eventuated the formation of bumps or other warped conditions in the supply roll.