Patent Description:
This disclosure relates generally to hardness testers and, more particularly, to hardness testers having a pivoting body and capable of providing power to accessories on the pivoting body.

Conventional hardness testers include selectable objectives or indenters which may be moved into position to perform a given task. Certain accessories and/or other components may require power. Conventional methods to power such accessories involve hard wiring the objective or accessory to a power source, which limits the movement of the objectives or indenters that can be achieved, and the hard wiring can wear out or be disconnected after a large number of movements. Some conventional hardness testers use slip rings to maintain electrical contact with accessories that are subject to moving. However, slip rings are expensive and subject to rapid wear, reducing reliability of power and/or data transfer. <CIT> discloses an objective changer having a movable carrier revolved relative to an immovable carrier, and having microscope objective useable in different switched positions. <CIT> discloses a bayonet mount for microscope objectives, having a rotatable turret for multiple-lens mounting.

Hardness testers having a pivoting body and capable of providing power to accessories on the pivoting body are disclosed, substantially as illustrated by and described in connection with at least one of the figures, as set forth more completely in the claims.

Disclosed example hardness testers include a swiveling carriage configured to: hold a plurality of indenters, objectives, and/or accessories; and swivel to selectively place one of the plurality of indenters, objectives, and/or accessories in a position to operate the one of the plurality of indenters and objectives. The example hardness testers further include a carriage mount configured to support the swiveling carriage, in which the swiveling carriage is configured to swivel with respect to the carriage mount. The hardness testers also include an electrical contact block attached to the carriage mount. The electrical contact block includes a plurality of electrical contacts configured to make electrical contact with a counterpart electrical contact block of at least one accessory coupled to an objective when the at least one objective or the at least one accessory is positioned in an operative position.

Disclosed examples improve the serviceability, reduces the size, and/or reduces the complexity of hardness testers by providing flexible and reliable electrical contact. The disclosed example hardness testers enable continuous rotation of the carriage carrying a combination of indenters, objectives, accessories, and/or other devices while being able to provide power and/or data communications with operative accessories, load cells, and/or other devices. The disclosed example hardness testers provide power and/or data connections without hard wiring the power and/or data connections (i.e., without a continuous hard wired connection between the source and receiver of power or data).

As used herein, the term "accessory" refers to any electrically operated component configured to be used on a hardness testing device, either alone or in conjunction with another device. Accessories may be controlled (e.g., closed loop or open loop control) or uncontrolled. Example accessories that may receive power and/or exchange data using the electrical contact block may include LED-based illuminators, alignment lasers, laser illuminators, general illuminators, load cells, piezoelectric drives, motors (e.g., DC motors), and/or incremental measurement systems.

Disclosed example hardness testing devices include: a rotating carriage configured to: hold an indenter and at least one accessory; and rotate to selectively place the indenter or the at least one accessory in an operative position to operate the indenter or the at least one accessory; a carriage mount configured to support the rotating carriage, the rotating carriage configured to rotate with respect to the carriage mount; and an electrical contact block mounted stationary with respect to the carriage mount, the electrical contact block including a plurality of electrical contacts configured to make electrical contact with a counterpart electrical contact block of the at least one accessory coupled to the rotating carriage when the at least one accessory is positioned in the operative position.

In some example hardness testing devices, the plurality of electrical contacts include a plurality of electrically conductive ball and spring plungers. In some examples, the plurality of electrical contacts are coupled to the electrical contact block via respective nuts. In some examples, the plurality of electrical contacts comprise terminal connectors coupled to the ball and spring plungers.

In example hardness testing devices, at least two of the plurality of electrical contacts are offset over a surface of the electrical contact block. A first one of the at least two of the plurality of electrical contacts is coupled to a first voltage source having a first voltage, and a second one of the plurality of electrical contacts is coupled to a second voltage source having a second voltage. In some examples, the at least one accessory includes: a first accessory coupled to a first location on the rotating carriage, the first accessory having at least two electrical contacts positioned to make contact with counterpart ones of the plurality of electrical contacts on the electrical contact block including at least a first one of the offset electrical contacts; and a second accessory coupled to a second location on the rotating carriage, the second accessory having at least two electrical contacts positioned to make contact with counterpart ones of the plurality of electrical contacts on the electrical contact block including at least a second one of the offset electrical contacts.

In some examples, the at least one accessory comprises at least one of: an LED illuminator, a laser, general illumination, a load cell, a piezoelectric drive, a motor, or an incremental measurement system. In some examples, the rotating carriage is configured to perform a hardness test using at least one indenter coupled to the rotating carriage when the indenter is in the operative position. In some examples, the operative position is located between a machine table and a rotational axis of the rotating carriage.

Some example hardness testing devices further include: feedback circuitry configured to output a signal representative of a position of the rotating carriage; and control circuitry configured to determine a position of the indenter, the objective, or the at least one accessory based on the signal. In some examples, at least one of the at least one indenter or objective, or the at least one accessory, is removable from the rotating carriage.

In some examples, the rotating carriage is configured to rotate around a rotational axis, the rotational axis being perpendicular to a direction of displacement of the rotating carriage by the carriage mount. Some example hardness testing devices further include control circuitry, in which at least two of the plurality of electrical contacts of the electrical contact block are configured to transmit at least one of data or a pulse width modulation (PWM) signal from the at least one accessory to the control circuitry. In some examples, the electrical contact block is stationary with respect to the carriage mount, and rotation of the rotating carriage causes the plurality of indenters and objectives to move with respect to the electrical contact block such that rotation of the rotating carriage causes the at least one accessory to move into contact and out of contact with the electrical contacts of the electrical contact block.

<FIG> is an elevation view of an example carriage <NUM>, an example carriage mount <NUM>, and an example electrical contact block <NUM> for a hardness tester <NUM>. <FIG> is a perspective view of the carriage <NUM>, carriage mounts <NUM>, and the electrical contact block <NUM> of <FIG>. The carriage <NUM>, the carriage mount <NUM>, and the electrical contact block <NUM> may be used to hold interchangeable indenters, lenses, illuminators, and/or other types of objectives and/or accessories.

The carriage <NUM> is configured to rotate (or swivel or pivot) about a carriage rotation axis <NUM> that is transverse to a direction of displacement <NUM> of the carriage <NUM>. The example carriage <NUM> is able to accommodate a large number of holders having indenters, lenses, and/or other objectives and/or accessories, and enables exact, reproducible test results in multiple rotational positions.

The hardness tester <NUM> is constructed as a vertical testing machine, in which the carriage <NUM> is held on one or more vertical carriage mounts <NUM>. The carriage <NUM> may be located directly above a machine table configured to receive a specimen to be tested. The example hardness tester <NUM> enables hardness tests according to the Brinell, Vickers, Rockwell, Super Rockwell, Knoop, Vickers depth measurement, ball pressure hardness, and/or Martens hardness test methods. The carriage <NUM> is guided vertically by the carriage mounts <NUM>, and may be acted on with the respective test force in the test direction (e.g., vertically).

The carriage <NUM> acts as a carrier of one or more objectives <NUM>, indenters <NUM>, and/or accessories. In some examples, the carriage <NUM> includes holders at different circumferential positions around the carriage <NUM>. The objectives <NUM>, indenters <NUM>, and/or accessories can be interchangeably attached to the holders. Additionally or alternatively, the objectives <NUM>, indenters <NUM>, and/or accessories may be detachable or permanently attached to the carriage <NUM> via the holders.

The carriage <NUM> may be rotated about the rotational axis <NUM> by a motor, such as a stepper motor. The motor may include a rotary encoder, and is controllable via a microcontroller or other control circuitry. The carriage <NUM> is disposed between the carriage mounts <NUM> on both sides and mounted via bearings in the carriage mounts <NUM> about the rotational axis <NUM>. In some other examples, the carriage <NUM> is mounted to a single carriage mount <NUM> via one or more bearings. The motor may be mounted on one of the carriage mounts <NUM> to pivot the carriage <NUM>, such as by deflecting discs and a drive belt.

The carriage <NUM> and/or the carriage mounts <NUM> may be acted on in a vertical direction to drive an indenter <NUM> in the direction of displacement <NUM> (e.g., vertically), such as to perform an indentation on a specimen. For example, the carriage mounts <NUM> (and, thus, the carriage <NUM>) is driven by a rotatably driven spindle in the axial direction of the spindle, which is identical to the direction of displacement <NUM>. An example spindle may include a ball screw. By controlling and monitoring displacement of the carriage mounts <NUM> and the carriage <NUM>, the test force can be controlled (e.g., by control circuitry). The control circuitry may monitor the exact alignment of the carriage <NUM> and/or the indenter <NUM>, which has been positioned in a test position by a rotational operation of the carriage <NUM> (e.g., via the motor) and monitoring the position of the indenter <NUM> via a rotary encoder, monitoring step counts of the motor, and/or any other incremental monitoring system, sensor (e.g., a Hall effect sensor), and/or feedback circuitry.

To detect and/or control divergence of the carriage <NUM> and/or the indenter <NUM> from a desired test position, the carriage mounts <NUM> may include load cells. The load cells may have strain gauges for detection. A monitoring device (e.g., control circuitry) receives output signals from the load cells, such that the motor of the carriage <NUM> is controlled in response to these output signals to maintain the carriage <NUM> and/or the indenter <NUM> in a correct position and/or orientation for testing. The load cells reduce or eliminate hardness testing errors and improve (e.g., ensure) compliance with hardness testing standards, including both depth measurements and optical measuring methods.

The carriage <NUM> may include other objectives and/or accessories, such as a light source <NUM> associated with optics attached to the carriage <NUM>. For example, the light source <NUM> may include LED illumination and an associated deflecting mirror. In some examples, the light source <NUM> is a ringlight, in which a mirrored light beam of the light source <NUM> and/or an object beam impinge on the semitransparent mirror that lies on a common axis corresponding to the axis of the objective. The axis is directed approximately at right angles to the rotational axis <NUM> of the carriage <NUM>. The optics and the light source <NUM> are fixedly and rigidly arranged in relation to each other in an interior of the carriage <NUM>. The image of the inspection is captured by a camera (e.g., a digital image sensor) via the semi-transparent mirror and a camera lens (e.g., the optics).

The light source <NUM> requires a source of power to provide the illumination. The electrical contact block <NUM> enables connection and disconnection of the light source <NUM> to a power source. In particular, the example light source <NUM> may be connected to the electrical contact block <NUM> when the light source <NUM> and the objective are positioned (e.g., by rotating the carriage <NUM> about the rotational axis <NUM>) in an operative position (e.g., aligned with the direction of displacement) in which the objective and the light source <NUM> are to be used to capture an image. When the carriage <NUM> rotates the light source <NUM> out of the operative position, contact between the light source <NUM> and the electrical contact block <NUM> is broken.

The electrical contact block <NUM> is attached to one of the carriage mounts <NUM>, so that the electrical contact block <NUM> is stationary and the accessories and/or other components attached to the carriage <NUM> may be rotated into and out of contact with the electrical contact block <NUM>. The electrical contact block <NUM> may be used to transfer power and/or data with accessories. Accessories that are to make contact with the electrical contact block <NUM> for power and/or data transmission have a counterpart electrical contact block. In some examples, the terminals <NUM> and the electrical contact block <NUM> enable communication with multiple, different load cells associated with corresponding indenters attached to the carriage <NUM>.

While the example hardness tester <NUM> of <FIG> is described as having the rotational axis <NUM> transverse to the direction of displacement <NUM> (e.g., the axis is horizontal), in other examples the carriage <NUM> may be configured to rotate about an axis that is parallel to the direction of displacement <NUM> (e.g., a vertical axis) and/or at an angle relative to the direction of displacement <NUM> (e.g., <NUM> degrees, <NUM> degrees, etc.). In such examples, the objectives, indenters, accessories, and/or other devices are attached to the carriage at an appropriate angle to effect hardness testing, and the electrical contact block <NUM> is positioned on a stationary surface so as to make electrical contact with an accessory in an operative position.

<FIG> is an elevation view of an example implementation of the electrical contact block <NUM> of <FIG>. <FIG> is a perspective view of the electrical contact block <NUM> of <FIG> is a cross-section side view of the electrical contact block of <FIG>. As illustrated in <FIG>, the electrical contact block <NUM> includes multiple electrical contacts <NUM>, <NUM>, <NUM> mounted to a mounting block <NUM>. The mounting block <NUM> attaches or mounts the electrical contact block <NUM> to the carriage mount <NUM>. While three example contacts <NUM>-<NUM> are shown in <FIG>, the electrical contact block <NUM> may include more or fewer electrical contacts to provide power and/or data.

Each of the example electrical contacts <NUM>-<NUM> includes a ball and spring plunger <NUM>, a nut <NUM>, and a ring terminal <NUM>. The nut <NUM> couples the ring terminal <NUM> and the ball and spring plunger <NUM> to the mounting block <NUM>. The ball and spring plunger <NUM> is biased toward contact with the electrical contact block of an accessory. The ring terminal <NUM>, or other terminal connector, is electrically coupled to the ball and spring plunger <NUM>, and may be coupled to a desired power and/or data connection. As illustrated in <FIG>, a spring <NUM> in each of the ball and spring plungers <NUM> biases a ball <NUM> toward a contact position to ensure adequate electrical contact. The ball and spring plunger <NUM> may be adjusted to increase or decrease the bias force.

The electrical contacts <NUM>-<NUM> correspond to multiple voltages that can be provided to power one or more accessories. Different accessories can include electrical contacts to be coupled to some, none, or all of the available electrical contacts on the electrical contact block <NUM>. For example, a first voltage source may be coupled to provide a first voltage across the electrical contacts <NUM>, <NUM>, and a second voltage source may be coupled to provide a second voltage across the electrical contacts <NUM>, <NUM>. A first accessory (e.g., the light source <NUM>) may include two terminals to make contact with the electrical contacts <NUM> and <NUM>, while a second accessory (e.g., a laser) may include two terminals to make contact with a different set of the electrical contacts <NUM> and <NUM>.

To avoid applying excess voltage to an accessory, two or more of the electrical contacts <NUM>-<NUM> are offset. For example, the electrical contact <NUM> is offset from both of the electrical contacts <NUM>-<NUM> in a direction <NUM> transverse to a travel direction <NUM> of the accessory.

The voltage(s) supplied via the electrical contacts <NUM>-<NUM> may be controlled (e.g., by control circuitry and/or a power source). For example, one or more voltage(s) may be increased and/or reduced to control illumination output by an LED. The voltage(s) may be controlled via a pulse width modulated (PWM) signal and/or by directly controlling the output voltage (e.g., DC voltage level, AC voltage amplitude, etc.).

<FIG> is a perspective view of an example accessory <NUM> including a laser <NUM>, positioned in electrically contact with the electrical contact block <NUM> of <FIG>. <FIG> is a plan view of the example accessory <NUM> and the electrical contact block of <FIG>. <FIG> is a perspective view of the example accessory <NUM> of <FIG>, including the contact terminals <NUM>, <NUM> configured to make contact with the electrical contact block <NUM>. <FIG> is a cross-sectional view of the accessory <NUM> of <FIG>. The electrical contact block <NUM> may provide power to the accessory <NUM>, including the laser <NUM>, when the accessory <NUM> is positioned the carriage <NUM> at the designated position.

To make contact with the electrical contact block <NUM>, the example accessory <NUM> includes terminals <NUM>, <NUM>, which are aligned to make contact with the electrical contacts <NUM>, <NUM> of the electrical contact block <NUM>. As the accessory <NUM> is moved into position by rotation of the carriage <NUM>, the terminals <NUM>, <NUM> are moved into alignment with the electrical contacts <NUM>, <NUM>. The ball and spring plungers <NUM> of the electrical contacts <NUM>, <NUM> are biased toward the accessory <NUM>. When the carriage <NUM> is rotated such that the accessory <NUM> is in an operative position, the ball and spring plungers <NUM> are biased into contact with the terminals <NUM>, <NUM>.

Additionally or alternatively, the hardness tester <NUM> may include circuitry that configures the power and/or data provided to the electrical contacts based on, for example, the type of accessory that is to be coupled to the electrical contacts. Accessories may then have substantially identical arrangements of the terminals <NUM>, <NUM> to connect to the same electrical contacts <NUM>-<NUM>. The circuitry may, for example, connect the electrical contacts <NUM>, <NUM> to a first voltage source to provide a first voltage for a first accessory (or control the voltage source to provide a first voltage). The circuitry may then connect the electrical contacts <NUM>, <NUM> to a second voltage source (or control the voltage source) to provide a second voltage for a second accessory.

<FIG> is a perspective view of the example light source accessory <NUM> of <FIG>, including contact terminals <NUM>, <NUM> configured to make contact with the electrical contact block <NUM> of <FIG>. <FIG> is a cross-sectional plan view of the light source accessory <NUM> of <FIG>. In a similar manner as the terminals <NUM>, <NUM>, the terminals <NUM>, <NUM> are aligned to make contact with the electrical contacts <NUM>, <NUM> when the light source accessory <NUM> is in an operative position (e.g., by rotation of the carriage <NUM>. The example light source accessory <NUM> may receive power via the electrical contacts <NUM>, <NUM>, which may provide a different voltage than the combination of electrical contacts <NUM>, <NUM> to which the light source accessory <NUM> is configured to make electrical contact.

<FIG> illustrate example electrical terminal blocks <NUM>-<NUM> having different arrangements of electrical terminals <NUM> that may be used for accessories. The example electrical terminals <NUM> may contact corresponding electrical contacts, similar or identical to the electrical contacts <NUM>-<NUM>, to receive power and/or exchange data via a corresponding electrical terminal block (e.g., the electrical contact block <NUM> of <FIG>).

In some examples, combinations of the terminals <NUM> exchange data using serial connections, parallel connections, bus-based connections (e.g., control area network (CAN) bus, PROFIBUS, etc.), differential signaling, pulse width modulation, and/or any other analog or digital signaling. As mentioned above, multiple combinations of two or more terminals <NUM> may provide different supply voltages, which can be accessed by accessories having electrical terminals <NUM> arranged to contact the corresponding electrical contacts on the electrical contact block <NUM>.

Claim 1:
A hardness testing device (<NUM>), comprising:
a rotating carriage (<NUM>) configured to:
hold an indenter (<NUM>) and at least one accessory; and
rotate to selectively place the indenter (<NUM>) or the at least one accessory in an operative position to operate the indenter (<NUM>) or the at least one accessory;
a carriage mount (<NUM>) configured to support the rotating carriage (<NUM>), the rotating carriage (<NUM>) configured to rotate with respect to the carriage mount (<NUM>); and
an electrical contact block (<NUM>) mounted stationary with respect to the carriage mount (<NUM>), the electrical contact block (<NUM>) comprising a plurality of electrical contacts (<NUM>,<NUM>,<NUM>) configured to make electrical contact with a counterpart electrical contact block of the at least one accessory coupled to the rotating carriage (<NUM>) when the at least one accessory is positioned in the operative position,
characterized in that at least two of the plurality of electrical contacts (<NUM>,<NUM>,<NUM>) are offset over a surface of the electrical contact block (<NUM>) in a transverse direction relative to a travel direction of the accessory when the accessory is held in the rotating carriage (<NUM>), and
wherein a first one of the at least two of the plurality of electrical contacts (<NUM>,<NUM>,<NUM>) is coupled to a first voltage source having a first voltage, and a second one of the plurality of electrical contacts (<NUM>,<NUM>,<NUM>) is coupled to a second voltage source having a second voltage.