Tared caliper

Abstract

A tared caliper having a measuring bar with a fixed jaw, a moving frame with a measuring indicator and with a moving jaw, an accurate feed mechanism, a measurement effort device with a calibrated flexible member. The calibrated flexible member in form the non-fixed replaced cylindrical compression spring with effort from 0.5 . . . 3 N to 25 . . . 60 N. The non-fixed replaced cylindrical compression spring coaxial into the rod inside the body by the measurement effort device. The body is connected to a moving frame. The force indicator includes from the marking window on the body and from the force scale on the rod. The rod is connected to an accurate feed mechanism. The rod is pressed to the flexible member.

Claims

1. A tared caliper to measure an object comprising: a measuring bar with a fixed jaw; a moving frame with a moving jaw, the moving frame slides through the measuring bar; a measuring indicator located on the moving frame; an accurate feed mechanism attached to the moving frame; a measurement effort device located between the moving frame and the accurate feed mechanism; wherein the measurement effort device includes: a body connected to the moving frame; a flexible member located inside the body; a rod inside the body, the rod having a first end pressed to the flexible member, a second end connected to the accurate feed mechanism, a scale, and a force indicator, the rod presses the flexible member; the flexible member is a replaced non-fixed compression spring with an effort from 0.5 . . . 3 N to 25 . . . 60 N; the force indicator includes a marked window and a force scale; wherein the flexible member moves sequentially and axially with the scale of the rod; wherein the accurate feed mechanism pushes sequentially and axially the flexible member through the force indicator; wherein the object is pressed by the fixed jaw and the moving jaw by the measurement effort device when the accurate feed mechanism moves.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic representation of the structure of the tared caliper claimed.

(2) FIG. 2 is a schematic representation of the structure of the measurement calibrated effort device of the tared caliper claimed.

DETAILED DESCRIPTION

(3) The subject invention tared caliper consists of a measuring bar 1 with a fixed jaw 2, a moving frame 3 along with a measuring indicator 4 and with a moving jaw 5, attached to an accurate feed mechanism 6; and at the same time it is different from the well-known prior art of the vernier caliper in the fact that a measurement calibrated effort device 7, which ensures an optimal effort during measurements with a vernier caliper, is arranged between the moving frame 3 and accurate feed mechanism 6 (FIG. 1).

(4) The measurement calibrated effort device 7 of the tared caliper is made in the form of body 8 (which is connected to the moving frame 3) with a calibrated flexible member 9 (in the form of metallic or non-metallic elastic spring) and a rod 10 (which is pressed to the flexible member 9 and connected to the accurate feed mechanism 6), at the same time the rod 10 has the scale for indication of the measurement effort, and a force indicator 12 is located in the body 8 for the purpose of control of the measurement effort indication scale when the rod 10 is moving (FIG. 2).

(5) A detail 11 being measured is located between the measuring jaws of the vernier caliper (fixed 2 and moving 5), which detail is pressed by the said measuring jaws 2 and 5 by means of the calibrated effort device 7, when the accurate feed mechanism 6 is moving (FIG. 1).

(6) Taking into account the physical and mechanical specific features and dimensions of the details being measured, the tared caliper provides the possibility of selection of almost any optimal measurement calibrated efforts in accordance with the conditions of use of the tared caliper.

(7) Based on the many-years of the practical experience in production of vernier calipers we recommend to use the following optimal nominal values of efforts P of the calibrated flexible members of the tared caliper:

(8) the effort of 0.5-3 N for the measurement of elastic details making use of measuring jaws having the length up to 40 mm;

(9) the effort of 2-12 N for the measurements of hard details making use of measuring jaws having the length of 40-60 mm or details made of elastic materials by means of measuring jaws having the length of 40-120 mm;

(10) the effort of 10-30 N for the measurements of hard details making use of measuring jaws having the length of 60-160 mm or measurement of elastic details by means of measuring jaws having the length of 100-250 mm;

(11) the effort of 25-60 N for the measurement of hard details with the length of measuring jaws of 250-500 mm.

(12) The measuring indicator 4 of the tared caliper (FIG. 1) can be made as one of three existing options:

(13) with analogue indication with the use of line scales and vernier scales (similarly to the vernier calipers of ShC ( ) type)

(14) with analogue indication with the use of dial (indicator) scale (similarly to the vernier calipers of ShCK ( ) type);

(15) with digital indication (similarly to the vernier calipers of ShCC ( ) type).

(16) The measurements with the use of the subject tared caliper are performed in the following order:

(17) the corresponding (optimal to the vernier caliper measurement conditions) replaceable flexible member 9 with the optimal calibrated effort P, which takes into account the above mentioned recommendations, is installed in the calibrated effort device 7 (FIG. 1, FIG. 2);

(18) detail 11 is pressed to the fixed measuring jaw 2 (FIG. 1);

(19) the moving measuring jaw 5 by means of the accurate feed mechanism 6 (through the calibrated effort device 7, connected to the moving frame 3 and said measuring jaw 5) is gradually approached to the detail 11 (measuring indicator 4 of the vernier caliper confirms the considerable reduction of gap between measuring jaws 2 and 5) until detail 11 is grasped to the minimum extent between the measuring jaws 2 and 5; in this case the force indicator 12 of the calibrated effort device 7 indicates the absence of load on the detail 11 in the initial position of the vernier caliper (FIG. 1, FIG. 2);

(20) in case of further grasping of the detail 11 being measured between the measuring jaws 2 and 5 (by means of the accurate feed mechanism 6 through the calibrated effort device 7) the approaching of the measuring jaws 2 and 5 is slowing down (only for several hundredth of millimeters); in this case the measurement effort of detail 11 is increasing apidly between the measuring jaws 2 and 5, achieving gradually the optimal calibrated effort P (FIG. 1);

(21) the moment of achieving the optimal effort of vernier caliper measurement is controlled by means of the force indicator 12 of the calibrated measurement effort device 7, the same ensures the exact value of the actual size of the detail 11 (FIG. 1, FIG. 2).

(22) In case of performing the repeated (duplicate) measurement the following shall be performed:

(23) the accurate feed mechanism 6 is withdrawn to the position of initial contact of the measuring jaws 2 and 5 with the detail 11 (with zero measurement effort) (FIG. 1);

(24) the loads of flexible member 9 are repeated by means of the accurate feed mechanism 6 with making of transfers (FIG. 2);

(25) in case of measuring the detail 11, which is different from the previous one (in terms of size or its physical and chemical properties), the measuring jaws 2 and 5 are opened beyond the dimensions of the detail 11, and after that the above mentioned transfers are repeated (FIG. 1).

(26) According to the claims of invention tared caliper the applicant prepared two operative embodiments of the vernier caliper of two standard sizes (ShCC ( )-150 and ShCC ( )-1000) in accordance with the subject invention tared caliper and of the conventional design according to Ukrainian State Standards DSTU 166: 2009 /2/, the comparative metrological control in the certified calibrating laboratory of Private Scientific and Research Company MIKROTECH, refer to the table.

(27) TABLE-US-00001 TABLE Range of measurements, Measurement error, mm mm/Length of measuring Measurement Non-classified/classified jaws, mm effort, N Invention Prior art /2/ Invention Prior art /2/ Invention Prior art /2/ Non-classified Classified Non-classified Classified (0-150)/40 (0-150)/40 Rated 8.0 Not rated 0.20 0.10 0.050 0.025 (0-1000)/150 (0-1000)/150 Rated 20.0 Not rated 0.70 0.50 0.100 0.065

(28) The comparative analysis of two standard sizes of the calibrated caliper with the existing prior arts /1/, as provided in the table, has fully proved the advantages of the proposed invention in terms of the measurement accuracy improvement and reduction of the measurement errors for the measurement, which are different in their ranges and length of the measurement jaws.

(29) As a result of the metrological control of the subject invention tared caliper and existing prior arts /1/ the possibility of the practical implementation, absolute technical and economic advantages of the invention tared caliper are confirmed.

(30) The subject invention tared caliper implements the advantages in the best way and eliminates the main disadvantage with respect to the entire group of the beam-type measuring tools.