Abstract: A constant-force device includes a first ratchet wheel mounted rotatably on a shaft and having first sawtoothed projections, a second ratchet wheel mounted on the shaft so as not to rotate relative to the shaft but to move along the shaft and having second sawtoothed projections opposed to the first sawtoothed projections, an intermediate ratchet wheel mounted on the shaft so as not only to rotate relative to the shaft but also to move along the shaft between the first ratchet wheel and the second ratchet wheel and having a pair of intermediate sawtoothed projections meshing with the first and second sawtoothed projections respectively, a biasing member configured to bias the second ratchet wheel towards the first ratchet wheel, and a lock mechanism configured to set the first and intermediate ratchet wheels in a connected or unconnected state.

Abstract: A caliper for measuring the size of an object, especially the thickness of an object with non-planar surfaces. After measured, the caliper can be removed from the object without changing the measured value. The caliper includes a scale ruler, a vernier slidably disposed on the scale ruler, a first jaw fixedly connected to the scale ruler and a second jaw pivotally connected to the vernier. In normal state, the second jaw is kept in a position in alignment with and in parallel to the first jaw, whereby the caliper can be used to measure the object in a common manner. After measured, the second jaw is rotated to another position, permitting the caliper to be removed from the measured object.

Abstract: A micrometer, including a constant force drive spring actuator configuration, is disclosed which comprises a frame, an anvil, a spindle, a linear displacement sensor that senses a displacement of the spindle, and an actuator including a button which is configured to move the spindle toward or away from the anvil. The spindle drive is attached to a constant force spring actuator comprising at least one constant force spring coil extending toward the spindle and attached between the spindle and the frame such that the sum of their forces drives the spindle toward the anvil with an approximately constant force. In some embodiments, the constant force spring actuator comprises at least two parallel constant force spring coils, extending in parallel toward the spindle. The constant force spring may be made more compact, exert a greater force, and have an extended life relative to known configurations.

Abstract: A micrometer, including a constant force drive spring actuator configuration, is disclosed which comprises a frame, an anvil, a spindle, a linear displacement sensor that senses a displacement of the spindle, and an actuator including a button which is configured to move the spindle toward or away from the anvil. The spindle drive is attached to a constant force spring actuator comprising at least one constant force spring coil extending toward the spindle and attached between the spindle and the frame such that the sum of their forces drives the spindle toward the anvil with an approximately constant force. In some embodiments, the constant force spring actuator comprises at least two parallel constant force spring coils, extending in parallel toward the spindle. The constant force spring may be made more compact, exert a greater force, and have an extended life relative to known configurations.

Abstract: A displacement measuring instrument includes a spindle screwed to a stationary sleeve, a thimble, an operation sleeve, and a constant pressure mechanism. The constant pressure mechanism includes: a rotary driving element rotatable together with the operation sleeve; a rotary driven element coupled to the rotary driving element in such a manner as to be rotatable together with the rotary driving element but not to be rotatable when a predetermined or more load is applied to the spindle; and a rotation transmitting mechanism transmitting a rotation of the rotary driven element to the spindle. A male thread portion with the same pitch as that of a male thread portion of the spindle is formed on the outer circumference of the stationary sleeve. A female thread portion is formed on the inner circumference of the thimble and screwed to the male thread portion of the stationary sleeve.

Abstract: A micrometer includes: a body; a fixed sleeve that is fixed to the body; a spindle that is screwed to the fixed sleeve; a thimble that is rotatably fitted to an outer circumference of the fixed sleeve and has an outer end connected to the spindle; an operation sleeve fitted over a range from an outer circumference of the thimble to an outer end of the spindle and being rotatable relative to the thimble; and a constant pressure mechanism that is disposed between the operation sleeve and the spindle, the constant pressure mechanism transmitting a rotation of the operation sleeve to the spindle and allowing a free rotation of the operation sleeve against the spindle when a predetermined or more amount of load is applied on the spindle. Ball bearings are disposed between the thimble and the operation sleeve.

Abstract: A displacement measuring instrument includes a spindle screwed to a stationary sleeve, a thimble, an operation sleeve, and a constant pressure mechanism. The constant pressure mechanism includes: a rotary driving element rotatable together with the operation sleeve; a rotary driven element coupled to the rotary driving element in such a manner as to be rotatable together with the rotary driving element but not to be rotatable when a predetermined or more load is applied to the spindle; and a rotation transmitting mechanism transmitting a rotation of the rotary driven element to the spindle. A male thread portion with the same pitch as that of a male thread portion of the spindle is formed on the outer circumference of the stationary sleeve. A female thread portion is formed on the inner circumference of the thimble and screwed to the male thread portion of the stationary sleeve.

Abstract: A micrometer includes: a body; a fixed sleeve that is fixed to the body; a spindle that is screwed to the fixed sleeve; a thimble that is rotatably fitted to an outer circumference of the fixed sleeve and has an outer end connected to the spindle; an operation sleeve fitted over a range from an outer circumference of the thimble to an outer end of the spindle and being rotatable relative to the thimble; and a constant pressure mechanism that is disposed between the operation sleeve and the spindle, the constant pressure mechanism transmitting a rotation of the operation sleeve to the spindle and allowing a free rotation of the operation sleeve against the spindle when a predetermined or more amount of load is applied on the spindle. Ball bearings are disposed between the thimble and the operation sleeve.

Abstract: An inside diameter measuring tool includes: a main body; an axially moving spindle having a male screw to be screwed to the main body; a plurality of contact pieces provided on the main body, the measuring pieces moving in a direction substantially orthogonal to the axial direction of the spindle; and a conical member interposed between the contact pieces and the spindle, the conical member advancing and retracting the contact pieces in the direction substantially orthogonal to the axial direction of the spindle. The lead of the male screw of the spindle is 1.0 mm or more and the cone angle of the conical member is less than 53 degrees. Preferably, the lead of the male screw is 2.0 mm and the cone angle of the conical member is approximately 28 degrees.

Abstract: A rotary movement converting mechanism for converting a rotary movement of a rotary body (43) into a linear movement of a movable body (2) has a support body (42) fixed to a body frame (3) and provided with a slit (42A) along an axial direction of the rotary body (43), a spiral groove (43A) formed on the inner circumference of the rotary body (43), and a top member (41) provided on the movable body (2). The top member (41) has an engaging member (41 A) inserted through the slit (42A) and having a tip end engaged with the spiral groove (43A), and a stop member (41C) for stopping the linear movement of the movable body (2) when a load is applied on the linear movement of the movable body (2). Accordingly, when a load is applied on the linear movement of the movable body (2), the linear movement is stopped and the minute displacement of the movable body (2) is restrained, thereby enhancing the stability of a measuring instrument in measuring a workpiece.

Abstract: A rotary movement converting mechanism for converting a rotary movement of a rotary body (43) into a linear movement of a movable body (2) has a support body (42) fixed to a body frame (3) and provided with a slit (42A) along an axial direction of the rotary body (43), a spiral groove (43A) formed on the inner circumference of the rotary body (43), and a top member (41) provided on the movable body (2). The top member (41) has an engaging member (41 A) inserted through the slit (42A) and having a tip end engaged with the spiral groove (43A), and a stop member (41C) for stopping the linear movement of the movable body (2) when a load is applied on the linear movement of the movable body (2). Accordingly, when a load is applied on the linear movement of the movable body (2), the linear movement is stopped and the minute displacement of the movable body (2) is restrained, thereby enhancing the stability of a measuring instrument in measuring a workpiece.

Abstract: A measuring instrument includes a spindle (11) provided to a body (1), a sleeve (31) movable in the same direction as the spindle and stoppable at a desired position, a connector (41) for connecting the sleeve and the spindle and allowing relative movement of the sleeve and the spindle in the moving direction thereof by a predetermined stroke; a pressure spring (61) accommodated in the sleeve for biasing the spindle in a direction for the spindle to abut to the workpiece through the connector, and a biasing force indicator (71) for indicating the pressure spring.

Abstract: A thimble (5) and a spindle (4) are rotated through a first constant-force device (70) by rotating an operation sleeve (6) integrally having a first operation section (61) and a second operation section (62). When a more than predetermined load is applied to the spindle (4), the first constant-force device (70) is actuated to spin the operation sleeve (6) idly. Since the operation sleeve (6) integrally has the first operation section (61) and the second operation section (62), both double-handed operation for holding the frame by left hand and rotating the first operation section (61) by right hand and single-handed operation for holding the frame and rotating the second operation section (62) with a single-handed are possible while retaining the same operability as in conventional operation during measurement.

Abstract: A measuring instrument includes a spindle (11) provided to a body (1), a sleeve (31) movable in the same direction as the spindle and stoppable at a desired position, a connector (41) for connecting the sleeve and the spindle and allowing relative movement of the sleeve and the spindle in the moving direction thereof by a predetermined stroke; a pressure spring (61) accommodated in the sleeve for biasing the spindle in a direction for the spindle to abut to the workpiece through the connector, and a biasing force indicator (71) for indicating the pressure spring.

Abstract: An inside of a U-shaped frame of a micrometer is made of a material having a smaller linear thermal expansion coefficient than an outside of the U-shaped configuration. Furthermore, a spindle can be made of a material having an extremely small linear thermal expansion coefficient. Accordingly, thermal deformation of the micrometer can be made smaller, and measurement accuracy is maintained even under a widely changing temperature.

Abstract: The instrument comprises two rigid yokes 1 and 2 capable of sliding one with respect to the other in the direction of the clearances to be measured between two components (R, 5) and 8. First of all, using an operating member 3, enough force to bring the ball R against the stop b1 of its socket is exerted on the component 5 by means of a spring 10. The comparator 9 is zeroed. Enough force is then exerted on the component 5 to bring the ball R to rest on the opposite stop b2 of its socket, this being done using an operating member 4 that acts in the opposite sense, the clevis mount 8 still being held between two resting faces 6, 7 of the yokes 1, 2. The clearance of the ball R in its socket is then read directly off the comparator 9. Application to measuring clearances in ball joints.

Abstract: A caliper or measurement apparatus for compressible sheet material includes first and second opposed contact faces which move relative to each other. A load cell in one face detects the load exerted there against, while a position indicator indicates the distance between faces. A microprocessor monitors load and position values continuously, corrects the load signal for noise and drift and determines whether a change in load cell output is correlated with advance of the measurement face. When a coupled load/position pattern is identified as a compression curve, the second contact face is assumed to have contacted the sheet and a thickness value is derived from the signals. Preferably, signal values are scaled and the processor operates on integral values, resulting in fast arithmetical operations that proceed in real time as the sensors are polled at a rate in excess of several kilohertz.

Abstract: A digital display micrometer gauge holds a workpiece to be measured between an anvil and a spindle. An engagement member is provided at an end of the spindle. An inner sleeve having an axial slit into which the engagement member is inserted, is secured to a U-shaped main frame, and an outer sleeve having a spiral groove, which is formed in the inner peripheral section thereof, is provided on the outer periphery of the inner sleeve to be circumferentially rotatable. By rotating this outer sleeve, the spindle can be driven at high speed. A main scale constituting a linear encoder is attached to a side surface of the spindle extending along the axis of the spindle, whereby the displacement amount of the spindle can be detected with high accuracy. A slide member slidable on the inner surface of the inner sleeve is provided at the end of the spindle where the engagement member is provided, and the spindle can be inserted into the inner sleeve together with the main scale attached thereto.

Abstract: A tool for measuring and checking the clamping force exerted by a movable spindle of a length measuring instrument such as a micrometer comprises a housing which is arranged to receive the free end of the spindle when a rim of the housing is placed against a surface of the instrument body around the spindle and the spindle is advanced, a force sensor which is located at the bottom of the housing for engagement by the free end of the spindle, and a read-out device for indicating the force exerted by the spindle as measured by the force sensor.

Abstract: The linear measuring device comprises a rail (1) with a fixed measuring jaw (4) and a slide (5) with a movable measuring jaw (6). A holding member (9) with a handle hole (10) is adjustably mounted on the rail (1). The slide (5) has a ring (20) arranged displaceably therein. This ring is connected with a clamping piece (30) via connecting elements (36, 39). This clamping piece, after attaining a predetermined measuring pressure, is brought into the clamped position on the rail (1) and thus permits the maintenance of a constant measuring pressure, the slide (5) being shiftable, with the clamping piece (30) being locked in place, under the action of the spring (32) with respect to the clamping piece (30) whereby the measuring object can be adjusted into the precise measuring position under spring force. The arrangement of handle hole (10) and ring (20) offers the advantage that maximally precise measurements can be quickly performed in correspondence with a scissor-like operation of the device.

Abstract: An instrument for measuring the dimensions of a rigid object (10) comprises a fixed member (1), a mobile member (2) slidably mounted on the fixed member, means for indicating the resulting measurement, and a locking device (3) allowing the mobile member (2) to be moved on the fixed member (1) to hold two bearing points (X, X') on the members in contact with the object (10) being measured with a substantially constant bearing force. The locking device comprises a first sleeve (20) slidably mounted on the mobile member (2) under the action of springs (24), and a second sleeve (30) slidably mounted on the fixed member (1) and inside which is a tipping ring (36) connected by a rod (40) to the first sleeve. The second sleeve (30), by acting on the first sleeve (20), enables loading the springs (24) to produce the bearing force when the instrument is in contact with the object (10) being measured.

Abstract: The slide (3) is provided with a pusher (5) mounted on an axle (7), wherein this axle (7) is connected to the slide (3) by way of a spring (8) pretensioned within a chamber (8a). If the measuring jaws (2) and (4) or (13) and (14) are pressed against the object to be measured with a specific measuring force, the axle (7) is displaced against the action of the spring, the displacement of the axle (7) being blocked by a clamping element (9) so that the force exerted on the object to be measured is given solely by the spring (8), the effect of the force exerted by the user on the pusher (5) being excluded. This arrangement permits precise measurement in opposite directions.