Recorders – Writers – Receiver and marker movable
Patent
1988-10-27
1991-05-28
Fuller, Benjamin R.
Recorders
Writers
Receiver and marker movable
G01D 1516
Patent
active
050198386
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates generally to planar chart recorders of the rotary type and charts for these. More specifically, this invention relates to portable chart recorders.
BACKGROUND OF THE INVENTION
Recorders of parameters such as temperature or humidity or both are well known. Typically, a recorder is provided with one or more pens that are directly coupled by suitable links to sensors. A replaceable planar circular chart is used which is mounted for rotation about an axis on a surface of the recorder under one or several pens. The recorder can be entirely mechanically driven, such as with a spring-wound motor to rotate the chart and with the stylus or pen mounted on, for example, a coiled, bimetallic temperature sensor that causes the pen to move along part of a circular path to record a temperature trace on the chart.
Because the pen motion is along a curved path, the chart bears time lines that are correspondingly curved. In this manner, parameter values can be read from a recorded trace, though with some level of difficulty due to the non-linear appearance of the reference time lines. When several different parameters are to be recorded on the same chart, the different traces, though usually of different colors to enhance their visual separation, are off-set in time with respect to each other. This is due to the different pivot arm lengths associated with the pens. As a result, the combination of curved time lines and time off-set between different traces makes these multiple trace charts more cumbersome to analyze.
In practical applications, it is important that recorders can operate reliably in the absence of electrical power. It is important, for example, for insurance purposes to know what the temperature and humidity conditions are in a computer room after a power failure has occurred. Also, when food is transported in a frozen state, it is desirable to have a record of temperature conditions within the transport.
Portability of a flat chart recorder, therefore, is an important characteristic. Fully mechanical recorders are portable but normally do not have sufficiently long operating cycles for many applications. Battery operated flat chart recorders often have practical time limits that are below desirable operating periods. Mechanically moved pens also tend to be inaccurate as well as difficult to provide compensation for.
FIELD OF THE INVENTION
With a rotational planar chart recorder in accordance with the invention a long-term portable operation is achieved while accommodating one or several parameter measurements. Multiple parameters can be recorded in a visually clear manner that is convenient to analyze. Long duration portable battery operations can be achieved of the order of twenty-eight day cycles while using electronically positioned pens.
This is achieved with one form for a chart recorder in accordance with the invention by employing a trace recording pen that moves parallel to a radius along a line that is substantially a straight radial path relative to the axis of rotation of the chart. The chart is provided with concentric circles representing parameter values and with straight radial time lines. As a result, multiple pen traces are particularly conveniently read and interpolated.
As described herein for one preferred form of the invention, a pair of pens are used. The pens can form ink traces or be heat elements or any other type of marker. Each pen is supported by an arm which is moved by an electrically powered actuator that is aligned to operate in parallel to the desired radial travel paths of the pens. The pen actuators are located on opposite sides of the travel paths and each operatively engages an arm. The arms extend towards each other so that their respectively-supported pens are placed in time proximity to one another relative to the rotation of the chart. In this manner, each pen can form a trace that uses the full scale of the chart without interference with the other pen. Yet different traces substantially relate to the same time as v
REFERENCES:
patent: 910630 (1909-01-01), Young
patent: 999412 (1911-08-01), Speer
patent: 1720148 (1929-07-01), Rodanet
patent: 3084014 (1963-04-01), Molloy
patent: 3914773 (1975-10-01), Harrower
patent: 4186404 (1980-01-01), Guyot
patent: 4212016 (1980-07-01), Ruhl
patent: 4337471 (1982-06-01), Hubbard
Leeds & Northrup, "Micromax Model R Recorder", 8/1934.
"Temperature Humidity Recorder" sales literature in Temperature Measurement Handbook and Encyclopedia.
"Strip Chart Recorders" sales literature in Temperature Measurement Handbook and Encyclopedia.
Crimmins James P.
McKinley William E.
Russell Robert G.
Fuller Benjamin R.
Hosmer Bruce E.
Omega Engineering Inc.
Tran Huan
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