Fader device

A fader device according to an aspect of the present invention includes: a guide rail that extends linearly and a slider that slidably engages with the guide rail, in which the slider includes a pressure-contact member that is to be in pressure contact with the guide rail, and a compression coil spring for jutting the pressure-contact member toward the guide rail.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a fader device.

Discussion of the Background

Apparatuses that combine a plurality of sound signals at an arbitrary ratio e.g., audio mixers such as a PA (public address) mixer and a DJ (disc jockey) mixer, each provided with a fader device for setting parameters for defining signal strength, etc. in a stepless manner, are widely used.

The fader devices allow setting of the parameters through either turning of an operation dial or linear movement of an operation knob. Of these, a fader device with an operation knob to be linearly moved is employed in many apparatuses, since such a fader device facilitates fine control owing to a larger stroke.

Such a fader device is designed in such a way that an appropriate resistance acts against a movement of the operation knob due to a friction force, in order that parameters being set are retained and a user can change the parameters as desired relying on a travel distance of the operation knob.

In many cases, the conventional fader device is provided with a guide rail that extends linearly and a slider that slidably engages with the guide rail, and configured such that the slider brings a friction-generating member into a pressure contact with the guide rail by means of a leaf spring, in order to generate a friction force between the guide rail and the slider.

For example, Japanese Unexamined Patent Application, Publication No. 2009-135426 proposes, as a device for adjusting an applied force (friction force) of a fader device, an applied force adjusting device provided with a slide member with a lever member for operation, and a shaft member (guide rail) to which the slide member is slidably attached. The slide member is provided with: a friction plate in pressure contact with the shaft member; a leaf spring that brings the friction plate into pressure contact with the slide member; and a cam that adjusts the pressure-contact force of the friction plate with respect to the shaft member, exerted by the leaf spring.

PRIOR ART DOCUMENTS

Patent Documents

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

In an apparatus that generates a friction force by means of a leaf spring, such as the applied force adjusting device disclosed in the aforementioned publication, the friction force may vary due to a manufacturing error, time-dependent alteration, etc., since a slight change in a deformation amount of the leaf spring leads to a great change in a pressing force. In order to enable correction of such a variation in the friction force, an adjustable width of a cam must be great; however, a greater adjustable width leads to a smaller appropriate angular range of a cam, and eventually an adjustment of the cam may be difficult.

In view of the aforementioned disadvantages, an object of the present invention is to provide a fader device that provides a stable and easily adjustable frictional force.

Means for Solving the Problems

A fader device according to an aspect of the present invention made for solving the aforementioned problems includes: a guide rail that extends linearly and a slider that slidably engages with the guide rail, in which the slider includes: a pressure-contact member that is to be in pressure contact with the guide rail or a friction target member extending in parallel to the guide rail; and a compression coil spring for jutting the pressure-contact member toward the guide rail or the friction target member.

DESCRIPTION OF THE EMBODIMENTS

A fader device according to an aspect of the present invention includes: a guide rail that extends linearly and a slider that slidably engages with the guide rail, in which the slider includes: a pressure-contact member that is to be in pressure contact with the guide rail or a friction target member extending in parallel to the guide rail; and a compression coil spring for jutting the pressure-contact member toward the guide rail or the friction target member.

Due to employing the compression coil spring, which is an elastic member exhibiting little variation in elastic force resulting from individual variability and wear with time, the fader device provides a stable friction force. In addition, since a change in elastic force in response to a change in compression amount of the compression coil spring is relatively small, the fader device can be easily adjusted to give a desired friction force.

Embodiments of the present invention will be described in detail hereinafter, with appropriate reference to the drawings.

First Embodiment

FIGS. 1 and 2illustrate a fader device according to a first embodiment of the present invention. The fader device includes a guide rail1that extends linearly and a slider2that slidably engages with the guide rail1.

Guide Rail

The guide rail1is attached to a housing3. In the present embodiment, the guide rail1is configured to have a specifically-shaped cross section so that a single rail can fix a posture of the slider2, i.e., can prevent the slider2from rotating about the guide rail1.

A material for the guide rail1is preferably superior in rigidity and abrasion resistance, and examples thereof include steel, stainless steel, carbon, a hard resin, a composite material thereof, and the like. Of these, stainless steel is particularly preferably used.

The guide rail1may be formed integrally with an entirety or a part of the housing3. As a specific example, the guide rail1and at least a part of the housing3may be formed integrally by folding a metal plate.

Slider

The slider2includes: a main body4slidably engaging with the guide rail1; a pressure-contact member5to be in pressure contact with the guide rail1; and a compression coil spring6for jutting the pressure-contact member5toward the guide rail1.

Main Body

The main body4includes an engagement portion7engaging with the guide rail1, and holds the pressure-contact member5and the compression coil spring6. The main body4may be configured to have a box-like shape, with one side being open to form the engagement portion7that receives the guide rail1.

The engagement portion7may either have a bushing or a bearing that engages with the guide rail1, or be configured to be in direct contact with the guide rail1depending on the material, etc. of the main body4.

The pressure-contact member5is pressed against the guide rail1by means of the compression coil spring6, to generate a friction force with respect to the guide rail1.

A shape of the pressure-contact member5is not particularly limited, and may have a planar contact surface to be in line contact or planar contact with the guide rail1, or a recessed contact surface to be in contact with the guide rail1at two sites at an interval in a sliding direction, so as to stabilize the friction force.

The pressure-contact member5is preferably retained on the main body4in such a way that the pressure-contact member5can move only in a direction perpendicular to the guide rail1on the main body4, i.e., not to move in a direction along the guide rail1on the main body4. Due to thus retaining the pressure-contact member5on the main body4, a constant friction force is generated between the pressure-contact member5and the guide rail1, whereby operability of the fader device is enabled to be improved.

A material of the pressure-contact member5is not particularly limited, and in light of stability of a contact state, is preferably a resin such as an ABS resin, polyacetal, etc. that is relatively high in modulus of elasticity and superior in abrasion resistance. The material for forming the pressure-contact member5may contain, for example, a filler for improving abrasion resistance, and the like.

Compression Coil Spring

The compression coil spring6presses the pressure-contact member5against the guide rail1to generate a friction force between the pressure-contact member5and the guide rail1. In other words, the compression coil spring6generates a friction force by permitting a normal reaction to act between the pressure-contact member5and the guide rail1. Therefore, the elastic force of the compression coil spring6is selected such that the appropriate friction force is generated between the pressure-contact member5and the guide rail1.

The lower limit of the force with which the compression coil spring6presses the pressure-contact member5against the guide rail1is preferably 0.1 N. Meanwhile, the upper limit of the force with which the compression coil spring6presses the pressure-contact member5against the guide rail1is preferably 0.4 N. When the force with which the compression coil spring6presses the pressure-contact member5against the guide rail1is less than the lower limit, sufficient sliding resistance may not be applied to the slider2, and consequently a user may not be readily adjust an amount of operation of the fader device. To the contrary, when the force with which the compression coil spring6presses the pressure-contact member5against the guide rail1is greater than the upper limit, the sliding resistance applied to the slider2may be undue, and consequently the user may not be readily adjust the amount of operation of the fader device.

The lower limit of the length of the compression coil spring6in a state in which the pressure-contact member5is in contact with the guide rail1is preferably 50% of the free length. Meanwhile, the upper limit of the length of the compression coil spring6in a state in which the pressure-contact member5is in contact with the guide rail1is preferably 90% of the free length. When the length of the compression coil spring6in a state in which the pressure-contact member5is in contact with the guide rail1is less than the lower limit, assembly of the fader device, i.e., a procedure of mounting the compressed compression coil spring6into the slider2, may be less simple. To the contrary, when the length of the compression coil spring6in a state in which the pressure-contact member5is in contact with the guide rail1is greater than the upper limit, a change in elastic force in response to a change in the length of the compression coil spring6may be so great that adjustment of the friction force between the pressure-contact member5and the guide rail1may not be easy.

The fader device is mounted in an apparatus such as a PA mixer in such a way that a position of the slider2can be detected. Examples of a procedure of detecting the position of the slider2include: a procedure of arranging a strip-shaped resistor in parallel to the guide rail1and making the slider2hold a terminal to be in slidable contact with the resistor, whereby an electric resistance between the terminal and an end of the resistor is detected; a procedure of using a contactless distance sensor such as an ultrasonic sensor, a procedure of measuring a travel distance of the slider2or a member attached to the slider2by an encoder; and the like.

Advantages

Due to employing the compression coil spring6, which exhibits little variation in elastic force resulting from individual variability and wear with time, the fader device of the present embodiment provides a stable friction force.

The fader device of the present embodiment enables adjustment of the force with which the compression coil spring6presses the pressure-contact member5against the guide rail1, owing to a shim or the like interposed between the main body4and the compression coil spring6. Since a change in elastic force in response to a change in compression amount of the compression coil spring6is relatively small, the fader device can be easily adjusted to give a desired friction force (sliding resistance of the slider2).

Second Embodiment

FIGS. 3 and 4illustrate a fader device according to a second embodiment of the present invention. The fader device includes: a guide rail1athat extends linearly; a friction target member8extending in parallel to the guide rail1a; a slider2athat slidably engages with the guide rail1a; a detection mechanism9that detects a position of the slider2a; and a driving mechanism10that electrically moves the slider2aalong the guide rail1a.

Constitutive elements of the fader device according to the present embodiment corresponding to the constitutive elements of the fader device illustrated inFIG. 1are referred to by the same reference numerals with “a” appended, in order to show the correspondence. The constitutive elements not particularly described of the fader device according to the present embodiment may be similar to those of the fader device illustrated inFIG. 1.

Guide Rail

The guide rail1ais attached to a housing3a. In the present embodiment, the guide rail1ais a circular cylindrical shaft. The slider2aslidably engages not only with the guide rail1a, but also with a friction target member8, whereby a posture thereof is fixed.

Friction Target Member

The friction target member8may be formed from a shaft similar to that of the guide rail1a. In addition, the friction target member8is attached to the housing3ain a similar manner to the guide rail1a, and retained in parallel to the guide rail1a.

Slider

As further illustrated inFIG. 5, the slider2aincludes: a main body4aslidably engaging with the guide rail1a; a pressure-contact member5ato be in pressure contact with the friction target member8; a compression coil spring6afor jutting the pressure-contact member5atoward the friction target member8; and a holding member11that holds the pressure-contact member5aand the compression coil spring6a.

Main Body

The main body4aof the slider2aincludes: an engaging portion7athat engages with the guide rail1a; an operation lever portion12that projects to the outside of the housing3aand to which a knob (not illustrated) is attached; a friction-contact portion13that is in contact with the friction target member8on an opposite side of the pressure-contact member5abeing in pressure contact; a plurality of positioning portions14that are capable of retaining the holding member11respectively at different positions in a stretch direction of the compression coil spring6a; and a through hole15that enables the holding member11to be pushed from an opposite side of the friction target member8toward the friction target member8.

The engaging portion7amay be configured to have a cylindrical bushing that slidably engages with the guide rail1a.

The operation lever portion12is preferably formed integrally with a portion of the main body4aretaining the engaging portion7a, so as to project from the portion retaining the engaging portion7ato an opposite side of the friction target member8, whereby a user's operation can be linearly converted to a travel distance of the slider2a.

The friction-contact portion13is in slidable contact with the friction target member8, on an opposite side of the pressure-contact member5abeing in pressure contact. In other words, due to the friction target member8being interposed between the friction-contact portion13and the pressure-contact member5a, the posture of the slider2aaround the guide rail1ais fixed.

The friction-contact portion13may be arranged either to face the pressure-contact member5a, or at a position deviated from a position facing the pressure-contact member5a. In the case in which the friction-contact portion13is arranged at a position deviated from a position facing the pressure-contact member5a, the friction-contact portion13is preferably provided in front of and behind the pressure-contact member5ain the sliding direction, such that an axial rotational force perpendicular to the pressure-contact direction and to the sliding direction, caused by a pressure-contact force of the pressure-contact member5awith respect to the friction target member8, is not applied to the slider2a.

The friction-contact portion13may be a hole formed on each of walls provided in front of and behind the pressure-contact member5ain the sliding direction, through which the friction target member8is inserted. Such a configuration enables the pressure-contact member5ato be correctly pressed against the friction target member8.

A material of the friction-contact portion13is preferably a resin such as an ABS resin, polyacetal, etc. that is relatively high in modulus of elasticity and superior in abrasion resistance.

The positioning portion14may be a set of a plurality of radially positioning grooves16that are provided around a central axis of the compression coil spring6aand are open in a direction of protrusion of the pressure-contact member5ajutted by the compression coil spring6a.

The holding member11retained by the positioning portion14constituted of the positioning grooves16may be configured to have a plurality of positioning projections17that protrude radially outward and are received by the positioning grooves16. The holding member11is pressed against a bottom end of the positioning groove16and eventually fixed with respect to the main body4a, by a reaction force of the compression coil spring6ajutting the pressure-contact member5a.

Due to each being different in depth of the positioning groove16, the plurality of positioning portions14retain the holding member11respectively at different positions in a stretch direction of the compression coil spring6a. By selecting the positioning portions14for retaining the holding member11, the length (amount of compression) of the compression coil spring6ain a state in which the pressure-contact member5ais in contact with the friction target member8can be adjusted, and in turn the pressure-contact force of the pressure-contact member5awith respect to the friction target member8, eventually the friction force between the pressure-contact member5aand the friction target member8can be selected.

The plurality of sets of positioning grooves16each constituting the positioning portion14may be formed around the central axis of the compression coil spring6aat angular intervals. Consequently, by attaching the holding member11to the main body4awhile selecting an angle thereof around the central axis of the compression coil spring6a, the friction force between the pressure-contact member5aand the friction target member8can be selected.

The through hole15on the main body4aexposes the holding member11on the opposite side of the friction target member8. As a result, the user can release the holding member11from the positioning portion14by pressing the holding member11toward the friction target member8so as to further compress the compression coil spring6a, and then make another positioning portion14retain the holding member11by rotating the holding member11about the central axis of the compression coil spring6a. In other words, by providing the through hole15on the main body4a, relatively easy adjustment of the friction force between the pressure-contact member5aand the friction target member8is enabled.

The pressure-contact member5ais held by the holding member11in a movable manner in a direction perpendicular to the friction target member8. In addition, the pressure-contact member5ais preferably held by the holding member11in such a way that movement thereof toward the friction target member8is restricted. As a result, the pressure-contact member5atogether with the compression coil spring6aare enabled to be held by the holding member11without being attached to the main body4a. By forming an integral unit of the pressure-contact member5a, the compression coil spring6aand the holding member11beforehand, easy assembly of the fader device is enabled.

In order that the holding member11holds the pressure-contact member5atogether with the compression coil spring6a, the pressure-contact member5amay be formed in a columnar shape or a bottomed cylindrical shape with a side to be in contact with the friction target member8being closed, and may be configured to have an engaging projection18to be held by the holding member11.

Compression Coil Spring

As described above, the compression coil spring6ais retained in a compressed state between the holding member11and the pressure-contact member5a.

Holding Member

The holding member11holds the pressure-contact member5aand the compression coil spring6a. The holding member11is pressed against the main body4aand fixed, by a reaction force generated when the pressure-contact member5ais pressed against the friction target member8by the elastic force of the compression coil spring6a.

The holding member11may be formed in a cylindrical shape such that the pressure-contact member5amay be inserted thereinto and guided in a direction perpendicular to the friction target member8.

As illustrated inFIG. 5, the holding member11can be configured to have an engaging groove19having a hooked shape with which the engaging projection18of the pressure-contact member5aengages, in order to hold the pressure-contact member5aand the compression coil spring6a. The hooked engaging groove19has an opening on an end of the holding member11on the friction target member8side. The engaging groove19may be a hooked groove that extends from the opening along the central axis direction of the compression coil spring6a, then along a circumferential direction of the holding member11, then toward the friction target member8along the central axis direction of the compression coil spring6a, and does not reach the end of the holding member11.

Detection Mechanism

A detection mechanism9is not particularly limited as long as a position of the slider2acan be detected, and may be a linear encoder such as a static encoder, a magnetic encoder, etc. Such a linear encoder may be provided with, for example: a mover20attached to the slider2aand including an electrode, a magnetic pole, etc.; and a detection circuit substrate21attached to the housing3aso as to face the mover20, on which a detection pattern is periodically formed for detecting a change in an electric field, a magnetic field, etc. caused by the mover20.

Driving Mechanism

A driving mechanism10is configured to move the slider2aalong the guide rail1aby, for example, power of an electric motor or the like, via a timing belt etc. The driving mechanism10preferably does not generate great resistance when the user moves the slider2a.

Advantages

The fader device of the present embodiment provides a stable friction force due to employing the compression coil spring6a, and enables easy adjustment of the friction force during movement of the slider2a, through selection of the positioning portion14on the main body4ain which the positioning projections17of the holding member11are to be engaged with the positioning grooves16.

Third Embodiment

FIGS. 6 and 7illustrate a fader device according to a third embodiment of the present invention. The fader device includes: a guide rail1bthat extends linearly; a friction target member8bextending in parallel to the guide rail1b; a slider2bthat slidably engages with the guide rail1b; and a detection mechanism9bthat detects a position of the slider2b.

Constitutive elements of the fader device according to the present embodiment corresponding to the constitutive elements of the fader device illustrated inFIG. 3are referred to by the same reference numerals with “b” appended, in order to show the correspondence. The constitutive elements not particularly described of the fader device according to the present embodiment may be similar to those of the fader device illustrated inFIG. 3.

Guide Rail

The guide rail1bis attached to a housing3b. In the present embodiment, the guide rail1bis a circular cylindrical shaft. The slider2bslidably engages not only with the guide rail1b, but also with a friction target member8b, whereby a posture thereof is fixed.

Friction Target Member

The friction target member8bmay be formed from a shaft similar to that of the guide rail1b. In addition, the friction target member8bis attached to the housing3bin a similar manner to the guide rail1b, and retained in parallel to the guide rail1b.

Slider

As further illustrated inFIG. 8, the slider2bincludes: a main body4bslidably engaging with the guide rail1b; a pressure-contact member5bto be in pressure contact with the friction target member8b; a compression coil spring6bfor jutting the pressure-contact member5btoward the friction target member8b; a holding member11bthat holds the pressure-contact member5band the compression coil spring6b; and an adjustment screw22that is attached to the main body4band fixes a position of the holding member11bin a stretch direction of the compression coil spring6b.

Main Body

The main body4bof the slider2bincludes: an engaging portion7bthat engages with the guide rail1b; an operation lever portion12bthat projects to the outside of the housing3band to which a knob (not illustrated) is attached; a friction-contact portion13bthat is in contact with the friction target member8bon an opposite side of the pressure-contact member5bbeing in pressure contact; and a receiving portion23that receives the holding member11bin a movable manner in the stretch direction of the compression coil spring6b, to which the adjustment screw22is rotatably attached.

The engaging portion7bmay be configured to have a cylindrical bushing that slidably engages with the guide rail1b.

The operation lever portion12bis preferably formed integrally with a portion of the main body4bretaining the engaging portion7b, so as to project from the portion retaining the engaging portion7bto an opposite side of the friction target member8b, whereby a user's operation can be linearly converted to a travel distance of the slider2b.

The friction-contact portion13bis in slidable contact with the friction target member8b, on an opposite side of the pressure-contact member5bbeing in pressure contact. Due to the friction target member8bbeing interposed between the friction-contact portion13band the pressure-contact member5b, the posture of the slider2baround the guide rail1bis fixed.

The receiving portion23may be configured to have: a hole for receiving the holding member11b; and a lid portion that closes an end of the hole on the opposite side of the friction target member8b, with a through hole15bprovided on the center through which the adjustment screw22is inserted.

The receiving portion23preferably has a guide structure that guides the holding member11bin the stretch direction of the compression coil spring6b. As the guide structure, for example, rib-like projections that engage with grooves formed on an outer periphery of the holding member11b, grooves that engage with ribs formed on an outer periphery of the holding member11b, or the like may be employed.

Holding Member

The holding member11bhas an internal thread into which the adjustment screw22is screwed. The internal thread can be provided by attaching a nut as in the present embodiment. When the holding member11bhas the internal thread into which the adjustment screw22is screwed, the position of the holding member11bcan be adjusted in a stepless manner by turning the adjustment screw22.

Adjustment Screw

As illustrated inFIG. 7, the adjustment screw22is attached through the through hole15bon the lid portion of the receiving portion23, such that a head to be turned by a driver, a hex wrench, etc. is exposed to the outside of the receiving portion23of the main body4b. In addition, the adjustment screw22has an anti-drop structure that is in contact with an inner face of the lid portion of the receiving portion23to prevent the adjustment screw22from dropping from the main body4b. As the anti-drop structure, for example, a locknut, a pin, a snap ring, and the like may be employed.

Advantages

The fader device of the present embodiment enables easy adjustment of the frictional resistance generated during movement of the slider2b, through adjustment of a force with which the pressure-contact member5bis pressed against the friction target member8b(normal reaction), by turning of the adjustment screw22.

Other Embodiments

The embodiments described above do not restrict the constituent features of the present invention. Therefore, any omission, substitution and addition of each of the constituent features of the embodiments can be made on the basis of the description of the present specification and common general technical knowledge, and such omitted, substituted and/or added features are to be construed to entirely fall under the scope of the present invention.

The fader device may not have the detection mechanism. As a specific example, in a configuration in which characteristic values such as electric resistance and capacitance, for example, between the guide rail and the friction target member are changed in accordance with the position of the slider, the fader device may be connected to an external circuit and used as a detection element.

In the fader device, in a case in which the guide rail alone is capable of fixing the posture of the slider, the friction-contact portion of the slider is not necessary, and the friction target member is only required to provide a face that extends linearly on which the pressure-contact member can slide, and may be, for example, a wall of the main body of the slider, ribs, etc.

INDUSTRIAL APPLICABILITY

The fader device of the present invention may be particularly suitably used for audio mixers such as a PA mixer and a DJ mixer.

EXPLANATION OF THE REFERENCE SYMBOLS