GB1583504A

GB1583504A - Measuring gauge

Info

Publication number: GB1583504A
Application number: GB2403177A
Authority: GB
Original assignee: Tesa SARL
Current assignee: Tesa SARL
Priority date: 1976-07-15
Filing date: 1977-06-08
Publication date: 1981-01-28
Also published as: BR7704212A; SE7708166L; SE423454B; FR2358637B1; FR2358637A1; IN148185B; JPS5311052A; IT1116765B; DE2727757B2; DE2727757A1; CH594874A5; DE2727757C3

Description

(54) MEASURING GAUGE (71i We, TTSA S.A. of 38 Rue Bugnon, 1020 Renens, Switzerland; a company organized under the laws of the State of Vaud, Switzerland, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:: The present invention relates to a measuring gauge comprising a fixing member adapted to be secured to a gauge support, a measuring element provided with a measuring contact adapted to be pressed by an elastic member onto an object to be measured, at least one guiding element being provided for enabling the relative displacement of the fixing element with respect to the measuring element, and a measuring transducer adapted to translate the said relative displacement of these twq,elements into measuring signals proportional to their displacement from their position on the line of action of the gauge.

Such gauges are already known which, mounted on appropriate supports such as 'V' supports, column supports or magnetic supports or framework mountings for multiple measurements, are used directly for the measuring and the control of the thickness or of the diameter of precision parts as well as to control their flatness, or the constancy of their thickness.

The precision and the small width of gauges of this type, in particular modern electronic gauges, renders them particularly useful for taking multiple measurements on parts of small dimensions, and whenever the space free for measuring is relatively limited, as for example for the control of the dimensions of a part in the course of manufacture on a machine tool.

However, the length of such gauges, in which the fixing element and the measuring element are disposed successively on the line of action of the gauge, means that they cannot be used directly for measurements such as the inner diameter of blind holes, particularly when this diameter is smaller than the length of the gauge.

For all these internal measurements one has recourse to gauges for internal measurements in which the radial displacement of the measuring contacts converted into an axial displacement which is measurable and proportional, as for example in cone-shaped gauges or those having oblique contacts.

Known gauges of the type described can therefore not be used for both internal and external measurements.

According to the present invention there is provided a measuring gauge comprising feeler supporting means including a first element and a second element disposed opposite each other respectively on both sides of an imaginary line parallel to the direction of measurement of the gauge, at least one guiding means to operatively connect to each other said first and second elements and allow relative movement thereof parallel to said imaginary line, spring means to oppose said movement of said first and second elements parallel to said imaginary line, a measuring transducer means operatively connected to said first and second elements for translating said relative movement into measurement signals proportional thereto, and identical mounting means on the free periphery of each-said first and second elements to allow respective connection thereof with a gauge support, or a measuring feeler, or an identical gauge the arrangement being such that a feeler fixedly attached to one of said elements may be biased by said spring means against a workpiece in one direction when the supporting means is fixedly connected by the mounting means of the other of said elements but is not so biased when the supporting means is connected by the mounting means of said one element.

Also according to the present invention there is provided a measuring gauge comprising feeler supporting means including a first element and a second element, said second element disposed opposite said first element whereby each of said first and second elements has a part of its peripheral surface facing the other element and the rest of its peripheral surface free, at least one guiding means to operatively connect to each other said first and second elements and allow relative movement thereof in parallel directions, spring means to oppose said movement of said first and second elements in opposite directions in said parallel directions, a measuring transducer means operatively connected to said first and second elements for translating said relative movement into measurement signals proportional thereto, and identical mounting means on said free peripheral surface of each of said first and second elements to selectively allow respective connection thereof with a gauge support, a measuring feeler, or an identical gauge, the arrangement being such that a feeler fixedly attached to one of said elements may be biased by said spring means against a workpiece in one direction when the supporting means is fixedly connected by the mounting means of the other of said elements but is not so biased when the supporting means is connected by the mounting means of the other of said elements but is not so biased when the supporting means is connected by the mounting means of said one element.

Further according to the present invention there is provided a measuring gauge comprising feeler supporting means including a first element and a second element, said second eleemnt disposed opposite said first element whereby each of said first and second elements has a part of its peripheral surface facing the other element and the rest of its peripheral surface outwardly free; a first mounting means on said outwardly free peripheral surface on said first element for selective connection thereof to a measuring feeler, a gauge support, or an identical gauge, a second mounting means on said outwardly free peripheral surface of said second element for selective connection thereof to a measuring feeler, a gauge support, or an identical gauge, said second mounting means being identical to said first mounting means, at least one guiding means to operatively connect to each other said first and second elements and allow relative movement thereof in parallel opposite directions, spring means to oppose said movement of said first and second elements in said parallel opposite directions and a measuring transducer operatively connected to said first and second elements for translating said relative movement into measurement signals proportional thereto, the arrangement being such that a feeler fixedly attached to one of said elements may be biased by said spring means against a workpiece in one direction when the supporting means is fixedly connected by the mounting means of the other of said elements but is not so biased when the supporting means is connected by the mounting means of said one element.

Thus either of the two elements can be used either as a gauge element or as a fixed element and the direction of measurement of the gauge is thus reversible by simply turning the gauge through 1800 parallel to the line of action.

The present invention will be described further, by way of example, with reference to the accompanying drawings in which : - Fig. 1 is a longitudinal section of a conventional gauge; Fig. 2 is a diagram illustrating the principle of operation of the gauge of Fig. 1; Figs. 3 and 4 represent schematically an elevation of a gauge in accordance with the invention; Figs. 5, 7 and 9 are elevations of variations in the mounting for external measurement; and Figs. 6, 8 and 10 are longitudinal views of variations in the mounting for internal measurements.

The known gauge shown in Figure 1 is an electronic gauge comprising a fixing element 1 in the form of a cylindrical tube adapted to be secured to a gauge support represented here by a hatch zone 2, and a feeler element 3 in the form of a cylindrical rod mounted coaxially therewith and equipped with a gauge contact 4.

The feeler element 3 is longitudinally slidably mounted in the fixing element r by means of a guiding element such as a ball bearing 5, ensuring the minimum of mechanical friction.

A resilient member, here a compression spring 6 is mounted concentrically with the feeler element 3, between the contact 4 and the end of the fixing element 1. This spring 6 urges the measuring contact 4 on to the object to be measured and is calibrated so as to produce the desired feeler pressure.

On certain gauges, this feeler pressure is obtained by elastic membranes by means of which the feeler element 3 is suspended in the fixing element 1.

A bellows 7 for protection against dust and swarf is generally fixed between the fixing element 1 and the feeler element 3.

The relative displacement between the fixing element 1 and the feeler element 3 is converted into a measurement signal pro portional to the displacement of the gauge by an inductive measuring transducer comprising two coils 8 and 9 forming part of a measuring bridge, mounted in the fixing element 1. The inductance of the coils 8 and 9 is modified by the displacement of an iron core 10, formed as an extension of the feeler element 3 within the coils 8 and 9.

An electric lead 11 carries the output from the measuring bridge to a processing circuit (not shown) of known type in which the voltage differences in the two coils 8 and are amplified and transmitted to an indi cator apparatus. A schematic diagram (Fig.

2) of this known gauge shows that, in this type of gauge, the fixing element 1 repre sented by the white rectangle, and the feeler element 3 represented by the hatched rectangle, can be considered as being mounted one behind the other along a line of action X of the gauge which passes through the contact 4.

On figure 2, the sensing direction deter mined by the spring 6 (Fig. 1) is repre sented by the arrow F in full lines, and the reaction of this spring on the support 2 of the gauge, transmitted via the fixing element 1, is represented by the arrow f in broken lines.

The schematic diagram (Fig. 3) of the gauge in accordance with the invention differs from that of the known gauge illustrated in Fig. 2 by the fact that the fixing element 1 and the feeler element 3 are not mounted along the line of action X of the gauge, but are mounted parallel to this and suitably equally spaced with respect to one another, either side of an imaginary line Y parallel to the line of action X of the gauge. ' The line of action X has not been shown on this figure, since the measuring contact 4 through which it passes is not shown and the measuring contact 4 could occupy any desired position around the gauge, as will be shown later.

,The two elements 1 'and 3 of the gauge which can be of similar or different shape are provided on their free periphery with fixing members3 which can be of any sort appropriate to their connection with a gauge support or a measuring contact. The fixing member 13 represented schematically here' is a dove-tail slide.

Thus mounted and equipped, each gauge element 1 and 3 can be used as desired as a fixed element or as a feeler element.

Simple rotation through 18(9" of the feeler around the imaginary line Y and parallel to its line of action has the effect of changing the direction of feeling of the gauge, as shown in Fig. 4.

With respect to the support 2, from Fig.

4 it can be seen that the feeler element, which, in Fig. 3, operated freely for the measurement in the direction of the arrow F, is now immobilised, and it is the fixing element 1, which, in its new reversed free position, can operate for sensing in the opposite' direction indicated by the arrow ,+.

In Fig. 3, the measuring contact would be provided on the feeler element 3, whilst in Fig. 4, the measuring contact would be provided on the'fixing element 1 which now effectively becomes the feeler element.

The positioning of the measuring contact on the element 1 or 3 would be selected for each case, and could also be in alignment with the imaginary line Y, spaced from this or displaced laterally as will be discussed later.

The connection between the fixing element and the feeler element could be of any suitable nature and would comprise at least one member to operatively connect said elements to each other and to allow for their relative movement for example, parallel to said imaginary line, and may include leaf springs, guides or interengaging pins and sockets. The measuring transducer could be electronic, mechanical, pneumatic or optical, and could be either integrally' formed with the feeler element, or provided as a discrete component connected to the two elements. The elastic member providing the feeler pressure or measuring force can be directly connected to the two elements or can even be replaced by an elastic element provided in the measuring transducer. It could also be adjustable if desired.

This reversibility facility of the elements and of the direction of measurement of the gauge in accordance with the invention per mis its use not only for internal measurement but also for external measurement and this advantage is illustrated in Figs. 5 to 10.

In Fig. 5 the gauge is shown equipped with two measuring contacts, one contact 14 mounted on the element 3 and a contact 15 mounted oti the element 1. The contact 15 is of a form' appropriate to measuring on the line of action X of the feeler passing through the other contact 14 and parallel to the imaginary line Y.

The direction of the feeler action of each element is the same as is indicated by the set of arrows F and f on Figs. 3 and 4.

Thus, it can be seen that the gauge may be used for making external measurements of a part 16, the two contacts 14 and 15 being pushed one towards the other.

'Fig. 6 shows the same mounting but after the reversal, with the contact 14 being fixed on the element 1 and the contact 15 on the element 3, which permits internal measurements of a part 17 to be taken, the two contacts 14 and 15 being displaced away from each bther.

This arrangement of the gauge with two contacts is advantageous for the measurement in situ of small parts, for example in the course of manufacture.

For larger parts, the same effect can be obtained by fixing the gauge on a gauge support'18 comprising a fixed contact 19, as shown in Fig. 7 and 8, or alternatively on a support comprising an abutment or an abutment anvil for the part of the object to be inëasured.

Further, two gauges (1-3, 1'-3', respectively) can be mounted opposite each other in reversed positions on a common support 20 as shown in Figs. 9 and 10. This configuration also offers the additional advantage of doubling the total useful range of measurement of the gauge.

Finally, one can mount two gauges together but with their lines of action at 900 with respect to each other, so that one could thus obtain measurements along two co-ordinates.

WHAT WE CLAIM IS:- 1. A measuring gauge comprising feeler supporting means including a first element and a second element disposed opposite each other respectively on both sides of an imaginary line parallel to the direction of measurement of the gauge, at least one guiding means to operatively connect to each other said first and second elements and allow relative movement thereof parallel to said imaginary line, spring means to oppose said movement of said first and second elements parallel to said imaginary line, a measuring transducer means operatively connected to said first and second elements for translating said relative movement into measurement signals proportional thereto, and identical mounting means on the free periphery of each said first and second elements to allow respective connection thereof with a gauge support, or a measuring feeler, or an identical gauge, the arrangement being such that a feeler fixedly attached to one of said clements may be biased by said spring means against a workpiece in one direction when the supporting means is fixedly connected by the mounting means of the other of said elements but is not so biased when the supporting means is connected by the mounting means of said one element.

2. A measuring gauge comprising feeler supporting means including a first element and a second element, said second element disposed opposite said first element whereby each of said first and second elements has a part of its peripheral surface facing the other element and the rest of its peripheral surface free, at least one guiding means to operatively connect to each other said first and second elements and allow relative movement thereof in parallel directions, spring means to oppose said movement of said first and second elements in opposite directions in said parallel directions, a measuring transducer means operatively connected to said first and second elements for translating said relative movement into measurement signals proportional thereto, and identical mounting means on said free peripheral surface of each of said first and second elements to selectively allow respective connection thereof with a gauge support, a measuring feeler, or an identical gauge, the arrangement being such that a feeler fixedly attached to one of said elements may be biased by said spring means against a workpiece in one direction when the supporting means is fixedly connected by the mounting means of the other of said elements but is not so biased when the supporting means is connected by the mounting means of said one element.

3. A measuring gauge comprising feeler supporting means including a first element and a second element, said second element disposed opposite said first element whereby each of said first and second elements has a part of its peripheral surface facing the other element and the rest of its peripheral surface outwardly free; a first mounting means on said outwardly free peripheral surface of said first element for selective connection thereof to a measuring feeler, a gauge support, or an identical gauge, a second mounting means on said outwardly free peripheral surface of said second element for selective connection thereof to a measuring feeler, a gauge support, or an identical gauge, said second mounting means being identical to said first mounting means, at least one guiding means to operatively connect to each other said first and second elements and allow relative movement thereof in parallel opposite directions, spring means to oppose said movement of said first and second elements in said parallel opposite directions and a measuring transducer operatively connected to said first and second elements for translating said relative movement into measurement signals proportional thereto, the arrangement being such that a feeler fixedly attached to one of said elements may be biased by said spring means against a workpiece in one direction when the supporting means is fixedly connected by the mounting means of the other of said elements but is not so biased when the supporting means is connected by the mounting means of said one element.

4. A measuring gauge substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. Further, two gauges (1-3, 1'-3', respectively) can be mounted opposite each other in reversed positions on a common support 20 as shown in Figs. 9 and 10. This configuration also offers the additional advantage of doubling the total useful range of measurement of the gauge. Finally, one can mount two gauges together but with their lines of action at 900 with respect to each other, so that one could thus obtain measurements along two co-ordinates. WHAT WE CLAIM IS:-

1. A measuring gauge comprising feeler supporting means including a first element and a second element disposed opposite each other respectively on both sides of an imaginary line parallel to the direction of measurement of the gauge, at least one guiding means to operatively connect to each other said first and second elements and allow relative movement thereof parallel to said imaginary line, spring means to oppose said movement of said first and second elements parallel to said imaginary line, a measuring transducer means operatively connected to said first and second elements for translating said relative movement into measurement signals proportional thereto, and identical mounting means on the free periphery of each said first and second elements to allow respective connection thereof with a gauge support, or a measuring feeler, or an identical gauge, the arrangement being such that a feeler fixedly attached to one of said clements may be biased by said spring means against a workpiece in one direction when the supporting means is fixedly connected by the mounting means of the other of said elements but is not so biased when the supporting means is connected by the mounting means of said one element.