GB2056663A - Dual head measuring apparatus - Google Patents

Abstract

A dual head measuring apparatus particularly for measuring carpets comprises measuring wheels 8, 15 connected in parallel with a counter or printer through a two way switch, each measuring wheel being connected (by flexible couplings 7,14) in series with transducers 6,13 for supplying electric impulses to the meter, alternatively connected by the switch to one or other of the measuring wheels. <IMAGE>

Description

SPECIFICATION improvements in measuring apparatus This invention relates to improvements in measur ing apparatus; Apparatus has been proposed to which the mate rial to be measured is passed between a measuring wheel and a pressure roller, the pressure roller being spring-loaded to maintain.the material in contact with the measuring wheel. The measuring wheel transmits the measurement to a meter which indi- cates the length which has passed through the apparatus and means may be prdvided for giving a signal after a predetermined length has been mea sured.

When measuring carpets the measuring wheel must engage the back of the fabric with the pressure roller contacting the pile surface. A 'pile up' and a 'Pile down' apparatus has had to be employed, one unit dealing with the measuring of carpets rolled with the 'pile up' and the other for carpets roller with the 'pile down'.

The object of the invention is a dual head appar atus which will measure the carpet rolled in a 'pile up' or 'pile down' condition and can be switched from one unit to the other according to the form in which the carpet has been rolled.

According to the invention a dual head measuring apparatus, particularly for measuring carpets com prises a circuit containing two measuring wheels connected in parallel with a counter or printer meter through a two way switch, each measuring wheel being connected in series with a transducer for supplying electric impulses to the motor alternative ly connected by the switch to one or other of the measuring wheels.

The invention will be described with reference to the accompanying drawings: Figure 1 is a side elevation of the measuring apparatus; Figure 2 is a side elevation of part of Figure 1 to a larger scale; Figure 3 is a section line 3-3 Figure 1; Figure4 is a circuit diagram; The apparatus consists of two castings, one casting being in the form of an arm 1 and the other in the form of a base 2 bolted together to provide a unit. A bracket 3 is connected to the arm 1 by a pivot pin 3a the pivoted bracket being in the form of a platform.

A measuring wheel 8 mounted on a shaft 9 is carried in bearings 5 on the bracket 3. The shaft 9 is coupled through a flexible coupling 7 to a transducer 6.

The bracket and plateform assembly is spring loaded by two springs 10 adjustable by screws 11 passing through the arm 1. A plate 12 is mounted on the base 2 carrying a tranducer 14 and a shaft 14a mounted in bearings 5a supporting a second measuring wheel 15, the measuring wheels 8,15 being kept in pressure contact by the springs 10.

The wirings from the transducers 6, 13 are con nected to a terminal block 6, carried on the underside of the base 2, the leads from a control console being also connected to the terminal block 16.

z In operation the transducers 6, 13 convert the revolutions of the driving shaft 9 or 14a into pulses, the transducers 6, being geared internally to provide a ratio of25 pulses for each revolution of the shaft.

The numerals 1 M377 and M.C3401 P refer to the part numbers of the integrated circuit employed.

mounted on the platform, is a transducer 6 and a flexible coupling 7 cOnnects the transducer 6 to a 'defined circumference measuring wheel 8 via a shaft 9.

Mounted on the base plate is a transducer 13 Figure 1. Afiexible coupling 14 Figure 1 connects the transducer 13 through bal races to a measuring wheel 15. The two measuring wheels 8 and 15 are now pressed together th rough spring tension.

thewirings from the transducers 6,13 are connected to a'terminal block 6, carried on the underside dtthe base 2, the leads from a control console being 'also connected to the terminal block 16.

In operatio.nthe transducers 6,13 convert the revolutions ofthe driving shaft 9 or 14a into pulses, the transducers, 6, 13 being geared internally,to provide a ratio of 25 pulses for each revolution of the shaft.

For example, if the circumference.of each measuring wheel 8,15 is 25cms, the transducer emits one pulse for one cm travel of the measuring wheel.

The output pulses'from the transducers are em ployed to drive an electronic counteriprinter housed in the console.

The transducerS may also have a built in sensing device to detect change in direction of the rotation of the shaft to provide adding or subtracting pulses to the electronic counter.

The material being measured passes through the throat of the unit over a guide plate 20 and between the measuring wheels 8, 15 and when the material is travelling in the direction of the arrow A a switch 52 is moved to a position Al so that count pulses from output A3 leads the count pulses for output B3 by 900.

This makes the counter add upwards. If the material is travelling in the direction of the arrow B the switch 52 is moved to the position B1 and the counter will receive count pulses from output A lagging behind the output pulses from output A3 lagging behind the count pulses from output B3 by 900. Then causes the counter to su b'tract or count downwards.

If, in the first instance, the materials travelling with the pile uppermost measurements are recorded from the measuring wheel 15 with the switch 52 in the appropriate position Figure 4, and pulses are transmitted to the counter from the transducer 13.

When the material is travelling pile down the switch 52 is placed in the pile down position and measurements are recorded from the measuring wheel 8 with pulses transmitted from transducer 6 to the counter.

Only one transducer is in circuit at any time.

A photo cell arrangement 17 Figure 1 detects when the material.is present in the unit and allows the counting circuit to operate, when the material runs out of the unit the count circuit is immediately broken, thus preventing count pulses occuring in the event of the measuring wheels spinning when the material leaves the measuring head occuring in the event of the measuring wheels spinning when the material leaves the measuring head.

Each transducer 6, 13 has a slotted disc which interrupts an infra-red light beam, which is then detected by two infra-red detectors. Each detector is physically separated so the infra-red beam received by one detector is phase displaced to provide suitable signals from the electronic circuits to determine direction sensing. The number of slots in the optical disc, gear ratio and circumference of the measurement wheel determines either imperial or metric measurement and the degree of accuracy/ increments required.

The 12V supply is regulated by IC3 to provide a highly stable 9V rail for IC1 and infra-red emitter D2.

Current through D2 is limited by R2 setting the infra-red light output. The processing electronics is duplicated for each infra-red detector TR1 and TR2.

TR1 receives the interrupted infra-red beam which causes current through it to vary so producing a varying input to the current amplifier IC1, a R1 and R2 act as current limiting resistors/RF suppression filters. VR1 applies negative feedback to optimise the operating level at this stage.

This signal then feeds the next stage IC1 b which acts as a schmitt trigger (R5,R6, R9 sets the biasing and hysterysis at IC1 b) to "clean up" the signal. IC2e provides a sufficiently low impedance drive for connection to the external counting electronics.

SW1 a and b provide direction change depending on the direction of counting required with reference to the direction of rotation of the measuring wheel.

D1 gives protection against reverse supply and overvoltage protection. C5 and C4 provide supply rail decupling whilst C1, C2 and C3 suppress electrical interference which could produce false counts.

The output signals from A and B are two square wave signals 90 phase displaced which are necessark for determining count pulses and direction sensing.

Claims (1)

1. A dual head measuring apparatus particularly for measuring carpets comprising a circuit containing two measuring wheels connected in parallel with a counter or printer motor through a two way switch, each measuring wheel being connected in series with a transducer for supplying electric impuises to the motor alternatively connected by the switch to one or other of the measuring wheels.

2. A dual head measuring apparatus as in Claim 1, in which the transducer has a built in sensing device to detect change in direction of the rotation of the shaft.

3. A dual head measuring apparatus as in Claim 2, the transducer has a slotted disc to interrupt an infra-red beam for detection by two infra-red detectors.

4. A dual head measuring apparatus substantially as described with reference to the accompanying drawings.

New claims or amendments to claims filed on 30 Dec.1980 Superseded claims 1 New or amended claims:

1. A dual head measuring apparatus for measuring the length of pile up or pile down rolled carpets comprising two circuits connected in parallel and each containing a wheel and a sensing device to detect the direction of rotation of the measuring wheel and a transducerfor supplying electric pulses to the circuit a switch to connect each circuit alternatively in series with a counter or printing motor to transpose the pulses into units of length, according to which wheel is in contact with the side of the carpet remote from the pile.