GB2038006A - Apparatus for checking and adjusting a machine screw-driver - Google Patents

Apparatus for checking and adjusting a machine screw-driver Download PDF

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Publication number
GB2038006A
GB2038006A GB7943221A GB7943221A GB2038006A GB 2038006 A GB2038006 A GB 2038006A GB 7943221 A GB7943221 A GB 7943221A GB 7943221 A GB7943221 A GB 7943221A GB 2038006 A GB2038006 A GB 2038006A
Authority
GB
United Kingdom
Prior art keywords
driver
brake
screw
friction
pressure
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB7943221A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Daimler Benz AG
Original Assignee
Daimler Benz AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Daimler Benz AG filed Critical Daimler Benz AG
Publication of GB2038006A publication Critical patent/GB2038006A/en
Withdrawn legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
    • G01L5/24—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes for determining value of torque or twisting moment for tightening a nut or other member which is similarly stressed
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
    • G01L25/00—Testing or calibrating of apparatus for measuring force, torque, work, mechanical power, or mechanical efficiency
    • G01L25/003—Testing or calibrating of apparatus for measuring force, torque, work, mechanical power, or mechanical efficiency for measuring torque

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Braking Arrangements (AREA)
  • Details Of Spanners, Wrenches, And Screw Drivers And Accessories (AREA)

Abstract

In apparatus for checking and adjusting a machine screw-driver 4 to a predetermined tightening torque comprising a device loadable with a reproducable torque and a torque- measuring element 9, between the screw-driver and the loading device, for indicating the torque applied, the loading device is constructed as a friction brake with friction elements which can be applied hydraulically and a hydraulic arrangement is provided which permits of a reproducable pressure rise, which is adjustable with respect to its maximum value and/or pressure/time gradient, for the hydraulic loading of the friction elements. Preferably the brake is a disc brake 2 with brake saddle 7. The hydraulic loading of the friction elements may be effected by way of a pressure cylinder 8 loadable by a compressed-air cylinder 11 in which the effective pressure is controllable with respect to maximum value and/or rise in relation to time. <IMAGE>

Description

SPECIFICATION Apparatus for checking and adjusting a machine screw-driver The invention relates to apparatus, for checking and adjusting a machine screw-driver to a predetermined tightening torque, comprising a loading device, loadable with a reproducable torque, for the screw-driver and with a torquemeasuring element, between the screw-driver and loading device, for indicating the torque applied by the screw-driver.
An arrangement for the adjustment of a machine screw-driver is known in which a pack of disc springs is compressed by way of a screw spindle, until the screw-driver has reached the desired torque and a toothed clutch disengages.
The torque applied is indicated by means of a transducer. In another known arrangement, a spring disc is compressed by means of a screw spindle, the spring deflection being ascertained and indicated in m-kg.
These arrangements, however, have the disadvantage that the values obtained are dependent on several parameters, such as friction values for the spindle, spring characteristics and so forth and are consequently inexact.
The present invention seeks to provide a meaningful apparatus, consisting of known machine elements with known dimensions, which permits of precise checking and adjustment of a machine screw-driver by virtue of given constant comparison values which are variable in dependence upon the particular loading.
To this end, the loading device is constructed as a friction brake with friction elements which can be applied hydraulicly and a hydraulic arrangement is provided which permits of a reproducable pressure rise, which is adjustable with respect to its maximum value, for the hydraulic loading of the friction elements.
By friction elements actuated hydraulicly with predetermined pressure, an always reproducable maximum friction va!ue in the brake is achieved, so that the same friction value is available; at the same magnitude, as starting point for every checking or adjusting operation. Consequently, different values cannot be obtained and utilised for comparison measurement.
According to a further development of the invention, the hydraulic arrangement may be so constructed that the pressure rise is adjustable with respect to the pressure/time gradient. The initial or comparison value can then be varied according to the loading and adjusted for from very hard to very soft screwing operations.
The friction brake may be constructed as a disc brake with a brake saddle of the nature of a motorcar disc brake.
Finally, the hydraulic loading of the friction elements of the brake may be effected by way of a pressure cylinder, loadable by a compressed-air cylinder, of the nature of a motor-car master brake cylinder, the effective pressure in the compressedair cylinder being controllable with respect to maximum value and/or pressure rise in relation to time.
One embodiment of the invention will now be more fully described by way of example with reference to the accompanying diagrammatic drawing, which shows apparatus for checking, setting and adjusting a machine screw-driver.
The apparatus illustrated comprises a friction brake 2, similar to a motor-car disc brake, which is mounted on a table 1 and whose rotatable shaft 3 has, at one end, a ratchet-tooth clutch part (not shown) for engagement with a complementary part of the tool of a machine screw-driver to be checked. The shaft 3 is received in a bearing 5 which also receives the screw-driver 4. The screwdriver 4 is driven pneumaticly, for example by way of a feed duct 6, and transmits rotary motion through the clutch parts to the friction brake 2. A brake saddle 7 of known kind held over the brake disc 2 is hydraulicly loaded from a known master brake cylinder 8 and acts to apply the friction brake 2 with increasing pressure until the ratchet teeth of the screw-driver spring out of engagement or the clutch disengages.A transducer 9 or measured-value pick-up device mounted on the driving shaft 3 and operating with extensometer strips monitors the torsion, thus produced, of the shaft 3 and transmits the measured maximum value to a measured-value store 10, on which the measured torque can be read off in m-kg.
Advantageously, the brake cylinder 8 is loaded by a compressed-air cylinder 11 in which the rate of pressure rise is controllable by switches 12, 13 depending upon whether soft or hard screwing is required.
The rate of the pressure rise may be controllable with respect to maximum value and/or rise in relation to time.
The apparatus may comprise further units or components, such as a control manometer 14, a manometer 15 for the control pressure and a hand controller 16 for the screw-driver, as well as a switch 1 7 for inward control and, inter alia, a switch 1 8 for "screw-driver in".
1. Apparatus for checking and adjusting a machine screw-driver to a predetermined tightening torque comprising a loading device, loadable with a reproducable torque, for the screw-driver and a torque-measuring element, between the screw-driver and the loading device, for indicating the torque applied by the screwdriver, wherein the loading device is constructed as a friction brake with friction elements which can be applied hydraulicly and a hydraulic arrangement is provided which permits of a reproducable pressure rise, which is adjustable with respect to its maximum value, for the hydraulic loading of the friction elements.
2. Apparatus according to claim 1, wherein the hydraulic arrangement is so constructed that the pressure rise is adjustable with respect to the pressure/time gradient.
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Apparatus for checking and adjusting a machine screw-driver The invention relates to apparatus, for checking and adjusting a machine screw-driver to a predetermined tightening torque, comprising a loading device, loadable with a reproducable torque, for the screw-driver and with a torquemeasuring element, between the screw-driver and loading device, for indicating the torque applied by the screw-driver. An arrangement for the adjustment of a machine screw-driver is known in which a pack of disc springs is compressed by way of a screw spindle, until the screw-driver has reached the desired torque and a toothed clutch disengages. The torque applied is indicated by means of a transducer. In another known arrangement, a spring disc is compressed by means of a screw spindle, the spring deflection being ascertained and indicated in m-kg. These arrangements, however, have the disadvantage that the values obtained are dependent on several parameters, such as friction values for the spindle, spring characteristics and so forth and are consequently inexact. The present invention seeks to provide a meaningful apparatus, consisting of known machine elements with known dimensions, which permits of precise checking and adjustment of a machine screw-driver by virtue of given constant comparison values which are variable in dependence upon the particular loading. To this end, the loading device is constructed as a friction brake with friction elements which can be applied hydraulicly and a hydraulic arrangement is provided which permits of a reproducable pressure rise, which is adjustable with respect to its maximum value, for the hydraulic loading of the friction elements. By friction elements actuated hydraulicly with predetermined pressure, an always reproducable maximum friction va!ue in the brake is achieved, so that the same friction value is available; at the same magnitude, as starting point for every checking or adjusting operation. Consequently, different values cannot be obtained and utilised for comparison measurement. According to a further development of the invention, the hydraulic arrangement may be so constructed that the pressure rise is adjustable with respect to the pressure/time gradient. The initial or comparison value can then be varied according to the loading and adjusted for from very hard to very soft screwing operations. The friction brake may be constructed as a disc brake with a brake saddle of the nature of a motorcar disc brake. Finally, the hydraulic loading of the friction elements of the brake may be effected by way of a pressure cylinder, loadable by a compressed-air cylinder, of the nature of a motor-car master brake cylinder, the effective pressure in the compressedair cylinder being controllable with respect to maximum value and/or pressure rise in relation to time. One embodiment of the invention will now be more fully described by way of example with reference to the accompanying diagrammatic drawing, which shows apparatus for checking, setting and adjusting a machine screw-driver. The apparatus illustrated comprises a friction brake 2, similar to a motor-car disc brake, which is mounted on a table 1 and whose rotatable shaft 3 has, at one end, a ratchet-tooth clutch part (not shown) for engagement with a complementary part of the tool of a machine screw-driver to be checked. The shaft 3 is received in a bearing 5 which also receives the screw-driver 4. The screwdriver 4 is driven pneumaticly, for example by way of a feed duct 6, and transmits rotary motion through the clutch parts to the friction brake 2. A brake saddle 7 of known kind held over the brake disc 2 is hydraulicly loaded from a known master brake cylinder 8 and acts to apply the friction brake 2 with increasing pressure until the ratchet teeth of the screw-driver spring out of engagement or the clutch disengages.A transducer 9 or measured-value pick-up device mounted on the driving shaft 3 and operating with extensometer strips monitors the torsion, thus produced, of the shaft 3 and transmits the measured maximum value to a measured-value store 10, on which the measured torque can be read off in m-kg. Advantageously, the brake cylinder 8 is loaded by a compressed-air cylinder 11 in which the rate of pressure rise is controllable by switches 12, 13 depending upon whether soft or hard screwing is required. The rate of the pressure rise may be controllable with respect to maximum value and/or rise in relation to time. The apparatus may comprise further units or components, such as a control manometer 14, a manometer 15 for the control pressure and a hand controller 16 for the screw-driver, as well as a switch 1 7 for inward control and, inter alia, a switch 1 8 for "screw-driver in". CLAIMS
1. Apparatus for checking and adjusting a machine screw-driver to a predetermined tightening torque comprising a loading device, loadable with a reproducable torque, for the screw-driver and a torque-measuring element, between the screw-driver and the loading device, for indicating the torque applied by the screwdriver, wherein the loading device is constructed as a friction brake with friction elements which can be applied hydraulicly and a hydraulic arrangement is provided which permits of a reproducable pressure rise, which is adjustable with respect to its maximum value, for the hydraulic loading of the friction elements.
2. Apparatus according to claim 1, wherein the hydraulic arrangement is so constructed that the pressure rise is adjustable with respect to the pressure/time gradient.
3. Apparatus according to claim 1 or 2, wherein the friction brake is a disc brake, with a brake saddle, of the nature of a motor-car disc brake.
4. Apparatus according to any one of claims 1 to 3, wherein the hydraulic loading of the friction elements of the brake is effected by way of a pressure cylinder, loadable by a compressed-air cylinder, of the nature of a motor-car master brake cylinder, the effective pressure in the compressedair cylinder being controllable with respect to maximum value and/or rise in relation to time.
5. Apparatus for checking and adjusting a machine screw-driver substantially as hereinbefore described with reference to the accompanying drawing.
GB7943221A 1978-12-14 1979-12-14 Apparatus for checking and adjusting a machine screw-driver Withdrawn GB2038006A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19782853908 DE2853908A1 (en) 1978-12-14 1978-12-14 DEVICE FOR CHECKING AND ADJUSTING MECHANICAL SCREWDRIVERS FOR A SPECIFIC TIGHTENING TORQUE

Publications (1)

Publication Number Publication Date
GB2038006A true GB2038006A (en) 1980-07-16

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Family Applications (1)

Application Number Title Priority Date Filing Date
GB7943221A Withdrawn GB2038006A (en) 1978-12-14 1979-12-14 Apparatus for checking and adjusting a machine screw-driver

Country Status (3)

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DE (1) DE2853908A1 (en)
FR (1) FR2444268A1 (en)
GB (1) GB2038006A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2270169A (en) * 1992-08-24 1994-03-02 Lotus Car Testing torque wrenches(e.g.SPS)which sense fastener yield
FR2751077A1 (en) * 1996-07-15 1998-01-16 Blm Sas Di L Bareggi & C METHOD AND DEVICE FOR TESTING SCREWDRIVERS
WO1998010260A1 (en) * 1996-09-05 1998-03-12 Crane Electronics Ltd. Variable torque rate simulated test joint
DE102006059386A1 (en) * 2006-12-15 2008-06-26 Schatz Ag Simulation device for screwing procedures for checking servo screw driver, has circular stator disk that is arranged between pressure plate and brake disk, and rotary arranged in housing, where pressure plate is influenced

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3305457A1 (en) * 1983-02-17 1984-08-23 Schatz Testronic GmbH, 5630 Remscheid Method and device for testing power drivers
DE3322804A1 (en) * 1983-06-24 1985-01-03 Miag Fahrzeugbau GmbH, 3300 Braunschweig Explosion-proof industrial truck
DE29701570U1 (en) 1997-01-30 1997-03-13 Blm S.A.S. Di Luigi Bareggi & C., Mailand/Milano Movable, battery-operated testing device for power wrenches
DE10163287B4 (en) * 2001-12-21 2007-08-16 Schatz Ag Method and device for testing the turn-off behavior of yield-limit-controlled power wrenches
DE102005013786B4 (en) * 2005-03-24 2008-08-28 Alfing Montagetechnik Gmbh Machine capability examination in angular steps
CN101650237B (en) * 2008-08-14 2011-04-20 金顿科技股份有限公司 Load detector and load simulation device thereof

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1409795A (en) * 1964-07-16 1965-09-03 Simca Automobiles Sa Torque measuring device especially for screwing machine
GB1160279A (en) * 1966-12-12 1969-08-06 Laycock Eng Ltd Improvements in Pneumatically Controlled Load Cells

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2270169A (en) * 1992-08-24 1994-03-02 Lotus Car Testing torque wrenches(e.g.SPS)which sense fastener yield
FR2751077A1 (en) * 1996-07-15 1998-01-16 Blm Sas Di L Bareggi & C METHOD AND DEVICE FOR TESTING SCREWDRIVERS
WO1998010260A1 (en) * 1996-09-05 1998-03-12 Crane Electronics Ltd. Variable torque rate simulated test joint
DE102006059386A1 (en) * 2006-12-15 2008-06-26 Schatz Ag Simulation device for screwing procedures for checking servo screw driver, has circular stator disk that is arranged between pressure plate and brake disk, and rotary arranged in housing, where pressure plate is influenced
DE102006059386B4 (en) * 2006-12-15 2008-11-27 Schatz Ag Device for simulating screwdriving processes for the testing of power wrenches

Also Published As

Publication number Publication date
FR2444268A1 (en) 1980-07-11
DE2853908A1 (en) 1980-07-03

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WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)