Test instrument for determining the shear modulus of elastomeric materials

Claim 3

A monitoring device as set forth in claim 3 wherein said comparison circuits include a card reader operative to preset said upper and lower voltage limits in accordance with the punched data on a card for use with said card reader.

Claim 4

A monitoring device as set forth in claim 4 wherein said visual indicator means includes a printer for registering the numerical value of said output signal.

Claim 5

An instrument for testing a characteristic of a material which varies with time from the start of an operation on the material, said characteristic having upper and lower limits of acceptability which vary with time, program means having stored therein the upper and lower limits of acceptability for said characteristic at a particular time from the start of said operation and the time from the start of the operation at which the characteristic of said material is to be within said limits, signal means providing a first signal which varies in accordance with said characteristic, circuit means connected to said signal means for signaling when said signal is above a presettable upper level and when it is below a presettable lower level, said circuit means comprising means responsive to said program means for setting said levels and control means actuatable in response to a timing signal to render said circuit means effective to compare an input signal with said levels and to indicate its relationship thereto, means connecting said signal means to said circuit means whereby said first signal is applied as said input signal to said circuit means, timing means for providing said timing signal a predetermined time after being actuated by an actuating signal, said timing meanS including means responsive to said program to determine the time interval between said actuating signal and the timing signal, means connecting said timing means to actuate said control means, and initiating means for supplying said actuating signal to said timing means at the start of said operation.

Claim 6

In an instrument as defined in claim 6 wherein said circuit means comprises first and second voltage level detectors, each being actuated in response to a voltage above a respective predetermined level, said first voltage detector being actuated when said first signal has a voltage magnitude corresponding to the lower limit and said second voltage detector being actuated when said output signal has a higher magnitude corresponding to said upper limit.

Claim 7

In a testing instrument as defined in claim 7 wherein said circuit means comprises means responsive to said program means for applying preselected portions of said first signal which are different to said voltage detectors.

Claim 8

In a testing instrument as defined in claim 6 wherein said signal means comprises a voltage dividing circuit, reference potential means connected across said voltage dividing circuit, said voltage dividing circuit including adjustable means providing a voltage output which is a portion of said reference potential across said voltage dividing circuit, and means to vary said adjustable means in accordance with said characteristic, said voltage output constituting said first signal.

Claim 9

In a testing instrument as defined in claim 9 wherein said means in said circuit means responsive to said program means comprises means settable in response to said program to apply a first selected portion of said output voltage to one of said voltage detectors and a second preselected portion of said output voltage to said second voltage detector.

Claim 10

In a testing instrument for indicating whether or not the heat curing characteristics of an elastomer is within preselected limits comprising a motor operable to effect the testing of a sample of the material, means for creating an electrical output signal that is dependent on the viscosity of the material being tested, the viscosity and said electrical output signal normally varying with time from the start of testing and the acceptable limits for said signal varying with time, a plurality of comparison circuits, each comparison circuit having presettable upper and lower limits, respective means for actuating said comparison circuits to compare said electrical output signal with the preset limits for the circuit, program means for storing data indicating upper and lower limits for said signal at predetermined times with respect to the initiation of the curing operation and data indicating the time that the signal is to be within the stored limits, each of said comparison circuits comprising means responsive to said program means for setting the respective limits for the signal for a particular time, respective timing means for actuating each of said comparison circuits, each of said timing means including means set in response to said program means to set the timing means to provide a timing signal for the corresponding comparison circuit at a predetermined time after receiving an actuating signal, and means responsive to the start of the testing operation for applying an actuating signal to each of said timing means, and means for applying the timing signal from each of the said timing means to the respective comparison circuit to actuate the latter.

Claim 11

In a testing instrument as defined in claim 11 wherein each of said comparison circuits comprises first and second voltage detectors each having a fixed threshold level, and means responsive to said program means to apply different preselected portions of said electrical output signal to said voltage detectors.

Claim 12

An instrument for testing the characteristics of a material from a curve at preselected points on such a curve comprising: means for creating an output signal that is proportional to torque forcEs as a function of time and thermal cure of a material, a comparison circuit having preset limits of acceptability, said comparison circuit having a read circuit and a voltage detector circuit, said comparison circuit includes an upper and lower set potentiometer connected between said output signal and said voltage detector circuit, each of said set potentiometers having a plurality of resistances connected in series, time control means operative to actuate said comparison circuit at preset time intervals for comparing said output signal with said preset limits, said time control means being a time base generator in series with a capacitor and a unijunction transistor operative to actuate said read circuit, said time base generator having a plurality of resistances connected in series and subject to being shorted out by a plurality of contacts being operative selectively by a prepunched card which selects the combination of said contacts which preselects the number of said resistances in series to provide a preselected time interval to actuate said read circuit, said voltage detector means operative upon actuation of said read circuit to compare said output signal with said upper and lower set potentiometers, and visual display means responsive to the comparison by said voltage detector means of said output signal with said preset limits of said upper and lower set potentiometers to indicate whether said output signal is within said limits at said preset time intervals.