Patent Application
20120330607
This invention, as evidenced by the embodiments described and shown herein, relates generally to the linear tapes for conversion of length to circumference and diameter readings, and more particularly to such a tape with computation and display structure to provide digital readings of circumference and diameter of an object.
There are a myriad of uses for linear tapes which can be formed into a circle around the outside or the inside of a circular object to provide readings for circumference or diameter. A pi conversion can be incorporated into a vernier device with permanent markings on the end of the tape that cooperatively aligns with the vernier device to provide visual readings of diameter. Of course, length (circumference) markings can be read directly with the tape in place on or in the object being measured.
It is well known that vernier readings, however precise, are still approximations at the very point of precision. Not only is there some element of interpolation, the number or distance read depends on the eyesight and care of the user.
Embodiments of the present invention removes any imprecision that may result from user error and interpolation of the vernier apparatus by providing precise digital readings of circumference and diameter.
A tape is formed with a machine readable side commencing from near the tail end and extending over a significant length of the tape toward the head end. At the head end is a unit incorporating a reader by which the machine readable tail end passes as the tape is fitted to the surface (external or internal) of the object being measured.
The unit has electronics which convert the readings from the tape to circumference and diameter, in either metric or English units, and provides a precise visual digital reading of the desired measurement in the desired units.
The head end of the device is formed with an opening through which the tail end of the tape passes as it slides along the unit and the distances on the machine readable portion of the tape are converted to the readings desired.
The purposes, features, and advantages of the disclosed device will be more readily perceived from the following detailed description, when read in conjunction with the accompanying drawing, wherein:
With reference now to the drawing, and more particularly to
It should be understood that available electronic readers, whether magnetic, optical, or other types, have the ability to read leading and trailing edges of markings to achieve even higher precisions than what the recorded or programmed increments would directly supply.
Tape 11 includes mounting element or vernier plate 15 connected to one end, the head end, of the tape. Tail end 17 of the tape passes through opening 13 at the head end of the vernier plate. Handle or knob 18 may optionally be provided for the user's convenience in handling the measurement device.
Mounted to vernier plate 15 is digital device 16 which is preferably internally equipped with a computation means which includes the pi formula or pi conversion factor for converting lengths to diameters. Device 16 has a rearward facing conventional magnetic or optical reader element (not shown) coupled internally to relatively simple electronic circuitry in the digital device. Tail end 17 of tape 11 passes over vernier plate 15 and under the digital device so that readable surface 12 faces and passes by the reader element in device 16 at a conventional close distance to enable the surface increments to be sensed by the reader element. Alternatively, digital device 16 may be formed with a slot through which the tape passes, but with the same orientation of surface 12 passing by the reader element.
Devices which provide a digital readout of linear measurements can be obtained from Master-Carr Supply Company in Santa Fe Springs, Calif. An example in the Master-Carr Catalog 116 is the Mitutoyo Electronic Scales. A linear readout device of the type here identified, can be programmed as shown in
When the measurement device described herein is to be employed to measure the circumference or the diameter of an object, tape 11 is applied loosely to the surface of the object, with tail 17 passing through opening 13 and behind digital device 16 so that the machine readable surface 12 is in reading position with respect to the rearward facing reader element in device 16. For initializing purposes, a setup line on the vernier plate is aligned with a setup line on the tape, as will be discussed in greater detail with respect to
Digital device 16 is programmed to perform as now described. After setup has been accomplished, tape 11 is pulled to a desired tension (nominally five pounds for external measurements) so that the tape is snugly against the external surface of the object being measured. The reader element effectively counts the number of increments on tape surface 12 that pass by after initialization and converts that length change to selected readings in digital readout window 23.
To read the circumference and diameter of the object, left button 21 may be depressed a set amount of times. For example, the digital unit may be programmed so that a single depression of button 21 shows the circumference of the object in inches; two depressions may show the diameter of the object in inches; three depressions can show the circumference of the object in metric units; and four depressions of button 21 may show metric diameter of the object. Of course, unit 16 can be programmed to react to any number of depressions to obtain any one of the four possible visual outputs. The readings may be also, or optionally, connected or transmitted to an external device, such as a monitor screen or any other electronic or visual display device. Further, the outputs of the reader element may be connected or transmitted to an external computation means which incorporates the pi formula and provides the selected diameter and circumference readings.
At the conclusion of the reading sequence, the tape may be relaxed and right button 22 is held depressed until the readings in window 23 disappear.
With reference now to
Vernier plate 15 is constructed with handle end 14 having knob 18, spaced from opening 13. Guide plate 25 is secured on the outside surface of plate 15 by any suitable means such as rivets 26. Stand offs, such as one or more washers, may be employed to provide gap 27 through which tape 11 can pass. The head end of tape 11 may be secured to vernier plate 15 by any suitable means.
Between guide plate 25 and digital device 16 appears “setup line” 29, scribed or etched on the outer surface of the guide plate.
As shown in
When alignment is achieved, right button 22 is depressed and held until a line of dashes is displayed in window 23. The tape is then placed around the item to be measured and pulled taught, with five pounds of tension. In window 23 initially appears one of the readings previously identified. Depressing left button 21 serially changes the readings between inches and metric, circumference and diameter. When the desire measurements have been completed, button 22 is again depressed and held until display 23 goes blank.
When not in use, digital device 16 can be programmed to turn off after any desire period of time, typically about five minutes. Actual measurement devices are typically constructed and calibrated in 12 inch increments, for example, 12″ to 24,″ 24″ to 36,″ 36″ to 48,″ 48″ to 60.″ The small diameter device can be 0.75″ to 2,″ or 2″ to 12.″ There are no theoretical size limitations, and examples of practical sizes have been set out here.
The apparatus shown in
Digital device 16 may be battery powered, or could be externally powered. It may have wireless capability, so that an operator can record the readings on a computer, for example. USB port 32 (
It should be noted that the above description relates to using the measurement device to determine external measurements. However, it may also be useful for internal circumference and diameter readings.
