Apparatus for feeding screws

The present invention provides an apparatus for feeding screws. In the apparatus, screws are scooped up from the storage container by a scooping unit and put onto a carrying unit. The screws are arranged in line and carried by the carrying unit and discharged through a discharge unit. The scooping unit includes a rotating arm which rotates on the outer wall of the storage container, and a magnet which is fastened to the front end of the rotating arm. The carrying unit includes a screw receiving part. The rotating arm rotates on the outer wall of the storage container to scoop up the screws using magnetic force of the magnet and load the screws onto the screw receiving part. The scooping unit further includes a magnet spacing part which is provided on the outer wall of the storage container. The magnet spacing part moves the magnet of the rotating arm away from the outer wall of the storage container, so that when the magnet is moved away from the outer wall of the storage container at the upper portion of the storage container, the attractive force of the magnet to the screws is reduced, thus dropping the screws onto the screw receiving part of the carrying unit.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus for feeding screws or the like, for example, metal rivets or tacks, having head parts and cylindrical shank parts (screwed parts) in such a way as to place the screws in a container, arrange them in lines, and discharge them one after another.

2. Description of the Related Art

A representative example of conventional apparatuses for feeding screws or the like was proposed in [Patent document 1] which was filed by the applicant of the present invention and entitled ‘Screw feeder’. The conventional screw feeder includes a storage container which stores a large number of screws S therein, and a guide rail which is provided in the storage container and extends to the outside of the storage container. The guide rail has an insert rail groove into which the screws S are inserted, and guides the screws S to discharge them in order. Furthermore, the screw feeder further includes a feeding unit which feeds screws S from the storage container onto the rail. The screws S fed onto the rail are moved along the rail and are stopped and arranged in line on a discharge side end of the rail by a stopper.

The feeding unit which feeds the screws S onto the rail includes a board which moves upwards and downwards to lift screws S and put them onto the rail. However, in the conventional technique, because there is a limit to the capacity of the board, many of the screws S which have been in the storage container are not loaded on the board. In other words, even if the size of the storage container is increased, the number of screws which can be loaded on the board is restricted.

Furthermore, because a relatively large number of screws are dropped from the board onto the rail at one time, the screws overlap with each other so that they cannot be satisfactorily arranged in line, with the result that several screws S are discharged at once. That is, the reliability of the operation is low.

In an effort to overcome the above-mentioned problems experienced with the conventional screw feeder, a parts feeding apparatus was proposed in [Patent document 2]. In this technique, a movable plate reciprocates on the outer surface of a storage container which contains metal parts. A magnet is mounted to the movable plate. A scraper is provided at a predetermined position in the storage container. Thus, a small amount of metal parts are scooped up from the storage container using the magnetic force of the magnet. The scraper scrapes the metal parts off the magnet. Thereafter, the metal parts are discharged to the outside one by one. However, although this apparatus can feed parts one by one, because the movable plate reciprocates, the apparatus is complicated and abrasion of the elements is increased. Furthermore, since the metal parts are separated from the magnet in such a manner that the scraper scrapes the metal parts off the magnet, the metal parts may be easily damaged. Thus, various kinds of transporting members or receiving members are required.[Patent document 1] Japanese Patent Laid-open Publication No. Heisei. 9-58847[Patent document 2] Japanese Patent Laid-open Publication No. 2001-287827

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide an apparatus for feeding screws which is constructed such that the capacity of a storage container for containing screws therein can be increased to reduce the frequency with which screws are supplied into the storage container, and the screws can be reliably arranged in line and discharged one by one.

In order to accomplish the above object, the present invention provides an apparatus for feeding screws, including: a storage container containing the screws therein; a scooping unit scooping up the screws from a lower part of the storage container; a carrying unit receiving the screws scooped up by the scooping unit and carrying the screws; and a discharge unit discharging the screws carried by the carrying unit to an outside. The discharge unit is installed ahead of the storage container. The scooping unit includes: a rotating arm rotating on an outer wall of the storage container; and a magnet fastened to a front end of the rotating arm. The carrying unit comprises a screw receiving part, wherein the rotating arm rotates on the outer wall of the storage container from a lower portion thereof to an upper portion thereof to scoop up the screws contained in the storage container using an attractive magnetic force of the magnet and loads the screws onto the screw receiving part of the carrying unit. The scooping unit further includes a magnet spacing part provided on the outer wall of the storage container. The magnet spacing part moves the magnet of the rotating arm away from the outer wall of the storage container, so that when the magnet is moved away from the outer wall of the storage container at the upper portion of the storage container, the attractive force of the magnet to the screws is reduced, thus dropping the screws onto the screw receiving part of the carrying unit.

The scooping unit may be provided on a sidewall of the storage container which is parallel to a direction in which the screws are being carried by the carrying unit.

Alternatively, the scooping unit may be provided on a rear wall of the storage container which is perpendicular to a direction in which the screws are being carried by the carrying unit.

The carrying unit may comprise a guide rail unit. The guide rail unit may include a rail and an inertial force applying unit. The rail guides the screws from an inside of the storage container to the outside thereof. The rail has therein an insert rail groove into which shank parts of the screws are inserted such that head parts of the screws are supported on inner edges of the rail that define the insert rail groove therebetween. The inertial force applying unit vibrates the rail forwards and backwards to apply inertial force to the screws inserted into the insert rail groove in the direction in which the screws are discharged.

Alternatively, the carrying unit may comprise a parallel roller unit. The parallel roller unit may include a pair of rollers provided parallel to each other, the rollers rotating in opposite directions, with spiral grooves respectively formed in the rollers. The spiral grooves may extend in directions opposite to each other such that when the rollers rotate. The spiral grooves may move on upper surfaces of the rollers in appearance in the direction in which the screws are discharged, so that the rollers guide the screws, head parts or ends of which are inserted into the spiral grooves, from an inside of the storage container to the outside thereof.

The magnetic spacing part may include a magnet guide roller which is installed on the rotating arm, and a magnet guide rail. The magnet guide rail may comprise an arc-shaped thick block part, inclined parts, and a depressed part, so that when the guide roller moves on the depressed part, the magnet of the rotating arm attracts the screws using magnetic force, and when the guide roller moves onto thick block part via the corresponding inclined part, the magnet is moved outwards away from the outer wall of the storage container to remove the screws from the magnet.

According to the present invention, a magnet of a scooping unit is provided on an outer wall of a storage container, so that screws are scooped up from the lower part of the storage container by the magnetic force of the magnet which rotates. Therefore, the depth of the storage container can be increased, thus increasing the capacity with which screws are contained in the storage container. Because the amount of screws contained in the storage container is increased, the frequency with which screws are supplied into the storage container can be reduced.

Furthermore, the magnet scoops up an appropriate amount of screws from the lower part of the storage container. The screws that are scooped up are dropped onto a screw receiving part of the carrying unit by moving the magnet away from the outer wall of the storage container above the carrying unit. Therefore, in the conventional technique which is operated in such a manner as to reciprocate the magnet, because the reciprocating unit easily gets worn, much time is required to maintain and repair the reciprocating unit. However, in the present invention, because the movement of the magnet is realized in a rotating manner, it can be smoothly operated and the probability of malfunction of the apparatus can be markedly reduced. In addition, in the conventional technique, because a scraper is used to separate screws from the magnet, excessive force may be applied to the screws, resulting in damage to the screws. As well, the scraper is also easily worn. Thus, replacement or repair of the scraper is frequently required. However, in the present invention, the operation of dropping screws on the carrying unit can be smoothly conducted in such a way as to move the magnet away from the outer wall of the storage container and eliminate the magnetic force applied to the screws. Hence, the screws can be smoothly dropped onto the carrying unit without applying external force to the screws. Thus, the screws can be prevented from becoming damaged, and the apparatus can also be prevented from becoming worn.

Furthermore, the scooping unit may be provided on a sidewall of the storage container. In this case, the depth of the storage container can be increased.

Alternatively, the scooping unit may be provided on a rear wall of the storage container. In this case, the width of the storage container can be increased. Thus, the entire size of the apparatus can be reduced. As well, screws can be uniformly supplied onto the carrying unit despite a simple mechanism being used.

Meanwhile, in the present invention, a guide rail unit may be used as the carrying unit for carrying the screws. In this case, the guide rail unit has a vibrating structure, so that screws can be rapidly and reliably fed.

Alternatively, rollers carrying in parallel and having spiral grooves may be used as the carrying unit for carrying the screws. In this case, the present invention can be used as an apparatus for feeding parts which can rapidly and reliably feed not only small screws but also large screws or the like.

Furthermore, in the present invention, a magnet guide rail for guiding a guide roller of the magnet includes an arc-shaped thick block part, inclined parts, and a depressed part forming a depression. Thus, the magnet guide rail can smoothly guide the magnet. Hence, abrasion of the components can be prevented. In addition, the screws can be smoothly scooped up by the magnet and smoothly removed from the magnet. As a result, the screws can be rapidly and reliably supplied onto the carrying unit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the present invention, a magnet is provided on an outer wall of a storage container so as to be rotatable. The magnet rotates on the outer wall of the storage container and thus scoops up an appropriate amount of screws from a lower part of the storage container using the magnetic force. When the magnet is disposed above a carrying unit while the magnet rotates, the magnet is moved away from the outer wall of the storage container, thus dropping the screws onto a screw receiving part of a guide rail unit (first embodiment) of the carrying unit, a guide plate (second embodiment) or a parallel roller unit (third embodiment). Therefore, the present invention can prevent screws from being damaged and reduce abrasion of components of the apparatus. In addition, the present invention is constructed such that screws are scooped up from the lower part of the storage container by the magnetic force of the magnet. Thus, the depth of the storage container can be increased, so that the capacity with which screws are contained in the storage container can be increased.

First Embodiment

Hereinafter, an apparatus for feeding screws according to a first embodiment of the present invention will be described in detail with reference to the attached drawings.

As shown inFIG. 1, in the screw feeding apparatus1according to the first embodiment of the present invention, a storage container2which receives screws S and occupies most of the volume of the screw feeding apparatus1is disposed at the left side ofFIG. 1. A scooping unit3is provided on the outside surface of the storage container2to scoop up screws S from the lower part of the storage container2. The scooping unit3loads the screws S on a carrying unit (4, a guide rail unit) which is provided in the storage container2. The loaded screws S are transported by the guide rail unit4which has an inertial force applying unit. Furthermore, the screws S which are being transported by the guide rail unit4are arranged in line by a brush rotating unit5. A discharge unit6discharges the screws S to the outside in regular order to feed the screws S to a desired place.

Below, the construction of the screw feeding apparatus1will be described in more detail.

First, the storage container2will be explained with reference toFIGS. 1,3and7. The storage container2is installed on a base11of the screw feeding apparatus1. The storage container2has a right plate21and a left plate22at the right and left sides based on the front side. Furthermore, a rear plate23is provided on the rear side of the storage container2. A front plate24is provided on the front side of the storage container2. Thus, the storage container2is formed in the shape of a rectangular box. The lower part25of the storage container2includes three (front/rear/left) inclined plates251a,251band251cwhich are inclined towards the central portion of the rectangular bottom of the storage container2. The lower part25further includes a planar bottom plate252which is provided on the center of the three inclined plates251a,251band251c. Thus, the lower part25of the storage container2forms a hopper shape.

To use the screw feeding apparatus1, a user inputs an appropriate amount of screws S into the open upper end of the storage container2. Most of the input screws S are received in the lower part25of the storage container2. The storage container2includes a front scooping chamber section26in which screws S which are in the front side of the storage container2are scooped up, and a rear scooping chamber section27which contains a screw receiving part43which receives screws S dropped into the rear side of the storage container2. Furthermore, the guide rail unit4which will be explained in detail later is installed in the storage container2and extends from the rear plate23to the front plate24. The discharge unit6is provided on the front surface of the front plate24of the storage container2. The scooping unit3is installed on the left plate22.

In the storage container2of the screw feeding apparatus of the present invention, as described below, because screws S are scooped up from the lower part of the storage container2using the magnetic force of a magnet which rotates, the depth of the storage container2can be increased, thus increasing the capacity with which screws S are contained in the storage container2.

As shown inFIGS. 1,2,4and5, the critical elements of the scooping unit3are disposed on the outer surface of the left plate22of the storage container2. The scooping unit3includes a drive unit31which rotates a magnet rotating unit32in one direction (in a counterclockwise direction ofFIG. 2). A drive motor311is provided on the front surface of the front plate24of the storage container2. An output shaft312of the drive motor311protrudes from the left plate22in the lateral direction. A rotary cam313and a pulley are provided on the output shaft312. A drive belt315is wrapped over the pulley314of the output shaft312and a pulley321of the magnet rotating unit32.

The pulley321is integrally provided on a first end of a rotating shaft322of the magnet rotating unit32. A second end of the rotating shaft322is rotatably supported by a bearing323(refer toFIGS. 3 and 5). The bearing323is provided on the left plate22of the storage container2. As shown inFIG. 4, a magnet mounting arm34and an arm support35which supports the magnet mounting arm34are installed between the bearing323and the pulley321. The arm support has opposite planar parts352which are formed in a circumferential part351thereof, in detail, are formed by cutting off diametrically opposite portions of the circumferential part351. Two arm bearings353are respectively installed in the planar parts352. The magnet mounting arm34has two rotating arm plates341. Each rotating arm plate341has an arm hinge pin342. The arm hinge pins342of the rotating arm plates341are rotatably inserted into the corresponding arm bearings353, so that the magnet mounting arm34can be rotatably supported by the arm support35.

As such, the magnet mounting arm34is mounted to the arm support35through the arm hinge pins342of the rotating arm plates341so as to be rotatable around the arm hinge pin342in the direction parallel to the rotating shaft322of the circumferential part351(in other words, the magnet mounting arm34is provided so as to be rotatable in the direction in which it is moved away from or is brought into contact with the left plate22). Furthermore, the magnet36is mounted to the distal end of the magnet mounting arm34. A magnet guide roller343is provided between the magnet36and the arm hinge pins342such that the magnet rotating unit32can smoothly rotate around the rotating shaft322.

As shown inFIGS. 4 and 5, the magnet guide roller343has a roller shaft346. A pair of roller mounting plates344is perpendicularly provided between the rotating arm plates341. Bearings345are respectively provided in the roller mounting plates344. The roller shaft346of the magnet guide roller343is rotatably supported by the bearings345. The magnet guide roller343rotates around the rotating shaft322along a circular trajectory.

The magnetic force of the magnet36attracts the screws S which are made of metal and are in the storage container2. The screws S that are attracted to the magnet36are scooped up by the rotation of the magnet36. Here, the magnet36is provided on the distal end of the magnet mounting arm34which rotates, such that the magnetic force thereof can be applied to the screws S in the storage container2.

A separation rail37is provided on the trajectory along which the magnet guide roller343rotates. The separation rail37constitutes a magnet spacing part33which functions to move the magnet36away from the left plate22. As shown inFIG. 6, the separation rail37has a magnetic force application range X1, transition ranges X2and X4and a separation range X3. In the embodiment, the magnetic force application range X1of the separation rail37is formed on the surface of the left plate22. The separation rail37includes a planar rail part371which has a semicircular shape and forms the separation range X3, and inclined parts372and373which extend from both ends of the planar rail part371and forms the transition ranges X2and X4. Of course, in consideration of a problem, such as abrasion of the left surface22, the separation rail37may be a circular rail which integrally has a thin planar rail part (depressed part)374, a thick planar rail part371and inclined parts372and373to form a contiguous structure. In this case, the thin planar rail part374defines the magnetic force application range X1.

That is, the magnet spacing part33includes the magnet guide roller343which are provided on the rotating arm plates341, and a magnet guide rail which is the separation rail37for guiding the magnet guide roller343. The magnet guide rail forms a circular trajectory. The circular trajectory is defined by a thick block part which is the planar rail part371having an arc shape, the inclined parts372and373and a portion (depressed part) of the outer surface of the left plate22. When the magnet guide roller343moves on the outer surface of the left plate22, screws S which have been in the lower portion of the rear scooping chamber section27are attracted by the magnetic attractive force of the magnet36mounted to the rotating arm plates341and are moved upwards along with the magnet36. After the screws S pass through the front scooping chamber section26and are scooped up to the upper portion of the rear scooping chamber section27, when the magnet guide roller343moves onto the planar rail part371via the inclined part372, the magnet36is moved away from the outer surface of the left plate22. Then, the attractive force of the magnet36with respect to the screws S in the storage container2is weakened, so that the screws S are dropped onto the screw receiving part43which will be explained later. Thereafter, the magnet guide roller343passes through the inclined part373and then moves onto the outer surface of the left plate22again.

The left plate22is made of stainless steel which is a nonmagnetic material. The screws S which are objects to be moved are magnetic substances. Therefore, the magnet36always attracts the screws S towards the left plate22. Furthermore, in the embodiment, although the left plate22has been illustrated as being made of nonmagnetic stainless steel, other sidewalls of the storage container may also be made of stainless steel. In addition, the sidewalls of the storage container may be made of another material, as long as it is a nonmagnetic material, for example, glass, synthetic resin, etc.

The guide rail unit4will be explained with reference toFIGS. 1 through 3and, particularly,7and8. Basically, the guide rail unit4is a feeder using an inertial force applying unit which was disclosed in [Patent document 2] stated above and moves the guide rail unit forwards and backwards to apply inertial force to screws S in the direction in which they are discharged.

As shown inFIG. 7, a rail support part which includes a rail support41, and a rail part42which is supported by the rail support41are almost horizontally installed in the upper portion of the guide rail unit4. The rail support41extends from the rear plate23of the storage container2to the front plate24. Moreover, the rail support41protrudes from the front plate24and extends to the discharge unit6. As shown inFIG. 1, the rail part42has an insert rail groove421extending along the longitudinal central axis of the rail part42. Shank parts (screwed parts, S1) of screws S are inserted into the insert rail groove421and are arranged in line. Two rails422aand422bare provided on opposite sides of the insert rail groove421. Furthermore, the screw receiving part43is provided on the opposite outer surfaces of the two rails422aand422b. The screw receiving part43receives screws S dropped downwards from the scooping unit3and supplies the screws S into the insert rail groove421.

In detail, the screw receiving part43contiguously extends from rail holding plates411aand411bwhich are provided on an upper surface of a support plate44of the rail support41. As shown inFIG. 1, the screw receiving part43includes a pair of receiving wings431aand431bwhich are disposed in the rear scooping chamber section27and are contiguous with the upper surface of the rail part42. The receiving wings431aand431bform a “V” shape.

Furthermore, the rail part42is removably supported by the rail holding plates411aand411bwhich press the opposite sides of the rail part42. The rail holding plates411aand411bare installed on an upper support plate441provided on the upper surface of the support plate44of the rail support41. Depending on the kind of screws to be fed, a rail part42including an insert rail groove421having a width and a depth corresponding to the screws can be selected and used. Furthermore, when necessary, the rail part42can be simply replaced with another one.

As stated above, the rail holding plates411aand411bare installed on the upper support plate441of the rail support41of the guide rail unit4. The inertial force applying unit which moves the rail part42forwards and backwards is provided under the rail support41. The support plate44of the rail support41has a “U” shape. In detail, the U-shaped support plate44includes a front support plate442, a bottom plate443and a rear support plate444which surround the storage container2. The front and rear ends of the rail support41are supported by the front and rear plates24and23of the storage container2through coupling holes (not shown) which are formed through the front and rear plates24and23. Here, preferably, gaps between the rail support41and the coupling holes must be smaller than the screws S to prevent the screws S from passing out of the storage container2through the gaps and prevent the screws S from being stuck in the gaps.

Furthermore, first ends of plate springs451aand451bare respectively coupled to the front support plate442and the rear support plate444of the support plate44of the rail support41. Fastening parts452aand452bof the plate springs451aand451bwhich are second ends of the plate springs451aand451bare fastened to the base11of the screw feeding apparatus1. Therefore, the entire guide rail unit4is supported only by the plate springs451aand451bso as to be movable in the longitudinal direction.

Meanwhile, an electromagnetic receiving plate46which is made of magnetic material protrudes from the lower end of the front support plate442of the support plate44in the lateral direction. As shown inFIGS. 8(a) and8(b), an iron core471of an electromagnet47is disposed adjacent to a distal end461of the electromagnetic receiving plate46protruding from the front support plate442such that the iron core471faces the side surface of the distal end461of the electromagnetic receiving plate46at a position spaced apart therefrom by a slight distance. The iron core471of the electromagnet47is fastened to the base11.

FIG. 8(b) is a plan view showing in detail the electromagnet47. The iron core471is disposed at the center of an electromagnetic coil472of the electromagnet47. A mounting board473is provided on the end of the electromagnet47which is opposite to a magnetic force applying surface4711of the iron core471. The mounting board473is fastened to the base11. Furthermore, the location of the guide rail unit is set such that the electromagnetic receiving plate46which is mounted to the front support plate442and faces the magnetic force applying surface4711of the iron core471is spaced apart from the magnetic force applying surface4711by a distance of about 1 mm.

When the electromagnetic coil472is supplied with power and turned on, magnetic force is generated on the magnetic force applying surface4711of the iron core471, so that the electromagnetic receiving plate46is attracted to the magnetic force applying surface4711. Hereby, the entire guide rail unit4is moved to the right inFIG. 7. When the supply of power to the electromagnetic coil472is interrupted and the electromagnetic coil472is turned off, the guide rail unit4is returned to its original position by the restoring force of the plate springs451aand451b. The electromagnetic receiving plate46of the guide rail unit4is also returned to its original position at which it is spaced apart from the magnetic force applying surface4711by a distance of about 1 mm. As such, the entire guide rail unit4is vibrated in the longitudinal direction (forwards and backwards) by applying square waves or A.C. to the electromagnetic coil472. This mechanism for vibrating the guide rail unit4realizes the inertial force applying unit.

In addition, the guide rail unit4which is the carrying unit is provided in the storage container2as if it were floating in air. Hence, the guide rail unit4can be prevented from being interfered with by the screws S in the storage container2, so that the screws S can be smoothly scooped up by the scooping unit3.

As described above, shank parts (screwed parts, S1) of screws S which are dropped onto the rails422aor422bor the “V”-shaped receiving wings431aand431bare inserted into the insert rail groove421, are arranged in line, and are carried to the outside. However, some screws S may not be correctly inserted into the insert rail groove421. In other words, some screws S in incorrect positions may be carried by the rails422aand422b. In this case, the screws S in incorrect positions must be dropped into the storage container2again. The brush rotating unit5conducts the function of dropping the screws S in incorrect positions into the storage container2.

As shown inFIGS. 1 and 3, a brush51is disposed above the rails422aand422bin the front scooping chamber section26. The brush51sweeps the surface of the rails422aand422bleftwards and rightwards. The brush51extends flatly a predetermined length in the longitudinal direction of the rails422aand422b. The brush51is fastened to a rotating shaft52by a height adjustment member53. The rotating shaft52passes through a rotating bearing54and the front plate24. A rotary arm55is provided on the front end of the rotating shaft52.

Power source for rotating the rotary arm55to the left and the right can be obtained by rotation of the drive motor311. In this case, the rotary arm55is preferably connected to the drive motor311through a link mechanism. A pressure contact roller56engages with the rotary cam313which is provided on the output shaft312of the drive motor311. The rotary cam313has a depression in a predetermined portion thereof. The pressure contact roller56is provided on a first end of a slider57which moves in the vertical direction. The slider57is constructed by a combination of a pair of stationary shafts (12, at a base side) and a slot (571, at a slider side). The slider57is biased towards the output shaft312of the drive motor311by a spring572. Thus, the slider57forcibly brings the pressure contact roller56into close contact with the cam surface of the rotary cam313.

Furthermore, a link58is rotatably provided at a predetermined position on the front plate24through a center link bearing581. A first link bearing582is provided on a first end of the link58. A second end of the slider57is rotatably coupled to the first link bearing582of the link58. In addition, a second link bearing583is provided on a second end of the link58and is rotatably coupled to a front rotary member551which is provided on the front end of the rotary arm55.

Therefore, when the rotary cam313having the depression rotates, the slider57and the pressure contact roller56which is in close contact with the cam surface of the rotary cam313move upwards and downwards. Then, the upward and downward movement of the slider57is transmitted to the front rotary member551and the rotary arm55through the link58, thus rotating them the left and the right. Thereby, the brush51and the rotating shaft52which is the central shaft of the rotary arm55are reciprocally rotated to the left and the right.

The distance between a brush tip of the brush51and the surfaces of the rails422aand422bis adjusted by the height adjustment member53such that the brush tip is brought into slight contact with head parts S2of screws S that are correctly inserted into the insert rail groove421. Here, if the position of the brush51is set such that the brush tip is disposed below the head parts of the screws S, when the brush rotates to the left and the right, it may excessively scatter the screws S or it may not be able to rotate. Therefore, it is preferable that the brush51be set at the above-mentioned position.

As described above, the scooping unit3loads screws S onto the guide rail unit4. The loaded screws S are carried by the guide rail unit4which has the inertial force apply unit using the vibration mechanism. In addition, the screws S are arranged by the brush rotating unit5and then discharged in order to the outside through the discharge unit6. That is, the discharge unit6feeds the screws S to the outside. Hereinafter, the discharge unit6will be explained in detail with reference toFIGS. 1 and 3.

Referring toFIGS. 1 and 3, a stopper61is provided on the front end of the insert rail groove421which extends outwards from the front plate24. Furthermore, a funnel-shaped bit guide62is provided above the stopper61. The bit guide62guides an end of a driver such that it can be correctly inserted into a head part S2of the corresponding screw S. The bit guide62is fastened to a bit guide mounting plate13through a bit guide bracket63. The bit guide mounting plate13is placed upright on the base11.

As stated above, in the screw feeding apparatus1of the first embodiment, screws S are discharged in order from the storage container2to the outside through the guide rail unit4. When the discharged screws S reach the discharge unit6which is provided on the front end of the guide rail unit4, the movement thereof is stopped by the stopper61. Furthermore, a front end sensor65is mounted to the support plate44of the rail support41through a sensor bracket64. When a predetermined time period has passed after the front end sensor65detects that a screw S reaches the stopper61, the entire operation of the screw feeding apparatus1is stopped.

After the screw S is disposed at the position of the stopper61, the bit of the driver is moved downwards under guidance of the bit guide62. Then, the bit which is guided by the bit guide62is coupled to the head part S2of the screw S. In this state, the screw S is drawn out by pulling the driver forwards. At this time, the front end sensor65detects that the screw S is drawn out, so that the drive unit restarts the operation of scooping up screws S in response to the detection of the front end sensor65.

As described above, the first embodiment of the present invention is operated in such a manner that the screws S are scooped up from the lower portion of the storage container2by the magnetic force of the magnet36which rotates. Therefore, the depth of the storage container2can be increased, thus increasing the capacity with which screws S or the like, for example, metal rivets or tacks, are contained in the storage container2. Because the amount of screws S contained in the storage container2is increased, the frequency with which screws S are input into the storage container can be reduced.

Furthermore, the magnet36is provided outside the storage container2. The magnet36scoops up an appropriate amount of screws S from the lower portion of the storage container2. The screws S that are scooped up are dropped onto the screw receiving part43of the guide rail unit4by moving the magnet36away from the sidewall22of the storage container2above the guide rail unit4. Therefore, in the conventional technique which is operated in such a manner as to reciprocate the magnet, because the reciprocating unit is easily worn, much time is required to maintain and repair the reciprocating unit. However, in the present invention, because the movement of the magnet36is realized by rotating, it can be smoothly operated and the probability of malfunction of the apparatus can be markedly reduced. In addition, in the conventional technique, because the scraper is used to remove screws from the magnet, excessive force may be applied to the screws, damaging the screws. As well, the scraper is also easily worn. Thus, replacement or repair of the scraper is frequently required. However, in the present invention, the operation of dropping screws on the guide rail unit4can be smoothly conducted in such a way as to move the magnet36away from the surface of the left plate22and reduce the intensity of the magnetic force applied to the screws. Hence, it is not required to apply a separate external force to the screws S to separate them from the magnet36. Thus, the screws S can be prevented from becoming damaged, and the apparatus can also be prevented from becoming worn. Moreover, the present invention is provided with the brush rotating unit5. Therefore, screws S or the like can be easily arranged in line by the brush rotating unit5, so that the screws S can be discharged one after another.

Second Embodiment

Hereinafter, an apparatus for feeding screws according to a second embodiment of the present invention will be described in detail with reference to the attached drawings.

As illustrated inFIGS. 9 and 10showing the critical part of the second embodiment, the screw feeding apparatus1according to the second embodiment is characterized in that a scooping unit3is provided on an outer surface of a rear plate23of a storage container2rather than on that of a sidewall of the storage container2, unlike the first embodiment. Below, the construction of the second embodiment will be explained in more detail.

Although the general structure of a right plate, a left plate and a front plate of the storage container2according to the second embodiment are not illustrated in the drawings, they remain the same as those of the first embodiment, therefore detailed descriptions will be omitted. However, a lower part28of the storage container2of the second embodiment differs from that of the first embodiment. As shown inFIGS. 9 and 10, the lower part28of the storage container2includes a semi-cylindrical receptacle281which is installed in the storage container2such that both ends thereof are close to the left and right plates of the storage container2and the central portion thereof is disposed at the lowermost position. The lowermost portion (corresponding to a central axis Z1) of the semi-cylindrical receptacle281is inclined such that it is lowered from the front plate24(refer toFIG. 2) to the rear plate23. The width of the semi-cylindrical receptacle281extends to the left and right plates of the storage container2.

To use the screw feeding apparatus1, a user inputs an appropriate amount of screws S into the open upper end of the storage container2. The input screws S are received in the semi-cylindrical receptacle281of the lower part28of the storage container2. Because the semi-cylindrical receptacle281is inclined downwards towards the rear plate23, the screws S gather adjacent to the rear plate23. Furthermore, in the same manner as the first embodiment, a guide rail unit4is installed in the storage container2and extends from the rear plate23of the storage container2to the front plate (equal to the front plate24of the first embodiment). In addition, a discharge unit is disposed on the front surface of the front plate of the storage container2. A scooping unit3which will be explained later is installed on the rear plate23. As well, a guide plate29(refer toFIG. 10) is provided at a predetermined position on the inner surface of the rear plate23. The guide plate29temporarily receives screws S dropped from the scooping unit3and guides the screws S onto a carrying unit4.

As described below, the storage container2according to the second embodiment is operated in such a way as to scoop up screws S from the lower portion of the rear plate23of the storage container2using the magnetic force of a magnet which rotates. Therefore, the width of the storage container2can be increased, thus increasing the capacity with which screws S are contained in the storage container2.

The general construction of the scooping unit3of the second embodiment remains the same as that of the first embodiment, therefore some explanations thereof will be omitted. As shown inFIGS. 9 and 10, the scooping unit3of the second embodiment is disposed on the outer surface of the rear plate23of the storage container2.

The scooping unit3includes a drive unit which has a drive motor311and rotates a magnet rotating unit32in one direction (in a counterclockwise direction ofFIG. 9). The drive motor311is provided on the front surface of the front plate (not shown) of the storage container2. An output shaft312of the drive motor311extends to the rear plate23of the storage container2. A rotary cam313and a pulley314are provided on the output shaft312. A drive belt315is wrapped over the pulley314of the output shaft312and a pulley321of the magnet rotating unit32.

The pulley321is integrally provided on a first end of a rotating shaft322of the magnet rotating unit32. A second end of the rotating shaft322is rotatably supported by a bearing343(refer toFIG. 4of the first embodiment) which is installed on the rear plate23of the storage container2. As shown inFIG. 4(of the first embodiment), a magnet mounting arm34and an arm support35which supports the magnet mounting arm34are installed between the bearing343and the pulley321. The arm support35has opposite planar parts352which are formed in a circumferential part351thereof, and which are in detail formed by cutting off diametrically opposite portions of the circumferential part351. Two arm bearings353are respectively installed in the planar parts352. The magnet mounting arm34has two rotating arm plates341. Each rotating arm plate341has an arm hinge pin342. The arm hinge pins342of the rotating arm plates341are rotatably inserted into the corresponding arm bearings353, so that the magnet mounting arm34can be rotatably supported by the arm support35.

As such, the magnet mounting arm34is mounted to the arm support35through the arm hinge pins342of the rotating arm plates341so as to be rotatable around the arm hinge pin342in the direction parallel to the rotating shaft322of the circumferential part351(in other words, the magnet mounting arm34is provided so as to be rotatable in the direction in which it is moved away from or is brought into contact with the rear plate23). Furthermore, the magnet36is mounted to the distal end of the magnet mounting arm34. A magnet guide roller343is provided between the magnet36and the arm hinge pins342such that the magnet rotating unit32can smoothly rotate around the rotating shaft322.

As shown inFIGS. 4 and 5of the first embodiment, the magnet guide roller343has a roller shaft346. Furthermore, a pair of roller mounting plates344is perpendicularly provided between the rotating arm plates341. Bearings345are respectively provided in the roller mounting plates344. The roller shaft346of the magnet guide roller343is rotatably supported by the bearings345. The magnet guide roller343rotates around the rotating shaft322along a circular trajectory.

The magnetic force of the magnet36attracts the screws S which are made of metal and are in the storage container2. The screws S that are attracted to the magnet36are scooped up by the rotation of the magnet36. Here, the magnet36is provided on the distal end of the magnet mounting arm34which rotates, such that the magnetic force thereof can be applied to the screws S in the storage container2.

Furthermore, a separation rail37is provided on the trajectory along which the magnet guide roller343rotates. The separation rail37constitutes a magnet spacing part33which functions to move the magnet36away from the rear plate23. As shown inFIG. 6, the separation rail37has a magnetic force application range X1, transition ranges X2and X4and a separation range X3. In this embodiment, the magnetic force application range X1of the separation rail37is formed on the surface of the rear plate23. The separation rail37includes a planar rail part371which has a semicircular shape and forms the separation range X3, and inclined parts372and372which extend from both ends of the planar rail part371and form the transition ranges X2and X4. Of course, in consideration of a problem, such as abrasion of the rear surface23, the separation rail37may be a circular rail which integrally has a thin planar rail part (depressed part)374, a thick planar rail part371and inclined parts372and373to form a contiguous structure. In this case, the thin planar rail part374defines the magnetic force application range X1.

That is, the magnet spacing part33includes the magnet guide roller343which is provided on the rotating arm plates341, and a magnet guide rail which is the separation rail37for guiding the magnet guide roller343. The magnet guide rail forms a circular trajectory. The circular trajectory is defined by a thick block part which is the planar rail part371having an arc shape, the inclined parts372and373and the outer surface of the rear plate23. As shown inFIGS. 9 and 10, when the magnet guide roller343moves on the outer surface of the rear plate23, screws S which have gathered at a position adjacent to the rear plate23in the semi-cylindrical receptacle281of the storage container2are attracted by the magnetic attractive force of the magnet36mounted to the rotating arm plates341and are moved upwards along with the magnet36. Thus, the screws S are scooped up to the upper portion of the inner surface of the rear plate23. When the magnet guide roller343moves onto the planar rail part371via the inclined part372, the magnet36is moved away from the outer surface of the rear plate23. Then, the attractive force of the magnet36with respect to the screws S in the storage container2is weakened, so that the screws S are dropped onto the guide plate29(within a range Z2designated by the shaded portion ofFIG. 10). The guide plate29has a V-shaped cross-section and the entirety thereof is inclined downwards towards the carrying unit4. The guide plate29temporarily receives screws S dropped from the scooping unit3and guides the screws S into the insert rail groove421of the carrying unit4.

After the scooping unit3drops the screws S onto the carrying unit4, the magnet guide roller343passes through the inclined part373and then moves onto the outer surface of the rear plate23again.

In the second embodiment, because not only the guide plate29is provided in the storage container2but also the scooping unit3is provided on the rear plate23, screws S can be dropped just above the insert rail groove421. Therefore, the operation of inserting the screws S into the insert rail to groove421can be facilitated.

Furthermore, the rear plate23is made of stainless steel which is nonmagnetic material. The screws S are objects to be carried and are magnetic substances. Therefore, the magnet36always attracts the screws S towards the rear plate23. Furthermore, in this embodiment, although the rear plate23has been illustrated as being made of nonmagnetic stainless steel, other sidewalls of the storage container may also be made of stainless steel. In addition, the sidewalls of the storage container may be made of another material, as long as it is a nonmagnetic material, for example, glass, synthetic resin, etc., in the same manner as that of the first embodiment.

Although the guide rail unit4of the carrying unit of the second embodiment will be explained below, because the construction of the guide rail unit4is almost the same as that of the first embodiment disclosed in [Patent document 2] stated above, only constructions different therebetween will be explained. Unlike the first embodiment, the second embodiment has neither the screw receiving part43for guiding screws S to the center of the rail part42nor the V-shaped receiving wings431aand431b. In place of them, the guide plate29is mounted to the rear plate23to guide screws S towards the center of the rail part42and drop the screws S thereonto. The guide plate29has a shape in which the width thereof is reduced towards the center of the carrying unit4, so that screws S which are not inserted into the insert rail groove421are dropped into the lower part of the storage container2and thus do not interfere with subsequent scooped-up screws S being inserted into the insert rail groove421of the guide rail unit4.

Furthermore, the general construction of the guide rail unit4except for the above-mentioned construction remains the same as that of the first embodiment, therefore detailed explanation will be omitted.

The brush rotating unit5also has the same basic construction as that of the first embodiment, except for a brush51and a drive mechanism for rotating a rotating shaft52.

The drive mechanism for rotating the rotating shaft52will be explained below. An elliptical rotary cam316is provided on the output shaft312of the drive motor311. A link lever3161is moved upwards and downwards by the elliptical rotary cam316through a pressure contact roller31611which is provided on the lower end of the link lever3161. The upper end of the link lever3161is coupled to a first end of a rotary lever3163. The rotary lever3163is rotatably supported around a rotary shaft3162. A slot3165is formed through the first end of the rotary lever3163. A movable pin3164which is provided on the upper end of the link lever3161is inserted into the slot3165of the rotary lever3163, so that the linear movement of the link lever3161is transmitted to the rotary lever3163through the movable pin3164to rotate the rotary lever3163. A second end of the rotary lever3163has an arc shape having the rotary shaft3162at a center thereof. Gear teeth are formed on the circumferential edge of the second end of the rotary lever3163. That is, the second end of the rotary lever3163forms an arc-shaped gear3166. Furthermore, a gear59is provided on the rotating shaft52of the brush51. The gear59engages with the arc-shaped gear3166of the rotary lever3163. Thus, when the arc-shaped gear3166rotates, the brush51sweeps the head parts S2of the screws S that are inserted into the insert rail groove421to drop screws S that are not correctly disposed in the insert rail groove421into the storage container2again. The general construction of the brush rotating unit5notwithstanding the above-mentioned construction remains the same as that of the brush rotating unit5of the first embodiment, therefore further explanation will be omitted.

As such, in the second embodiment, screws S are discharged in line to the outside of the apparatus by the operation of the above-mentioned components. Meanwhile, the discharge unit (not shown) of the second embodiment has the same construction as that of the discharge unit6of the first embodiment, therefore further explanation is deemed unnecessary.

As described above, in the same manner as the first embodiment, the second embodiment of the present invention is operated in such a manner that the screws S are scooped up from the lower part of the storage container2by the magnetic force of the magnet36which rotates. Therefore, the depth of the storage container2can be increased, thus increasing the capacity with which screws S or the like, for example, metal rivets or tacks, are contained in the storage container2. In particular, in the second embodiment, because the scooping unit3is installed on the rear plate23of the storage container2, the width of the storage container2can be increased compared to that of the first embodiment. Hence, the frequency with which screws S are input into the storage container can be reduced.

Furthermore, the magnet36is provided outside the storage container2. The magnet36scoops up an appropriate amount of screws S from the lower part of the storage container2using magnetic force. The screws S that are scooped up are dropped onto the guide plate29of the guide rail unit4by moving the magnet36away from the rear plate23of the storage container2above the guide rail unit4. Therefore, in the conventional technique which is operated in such a manner as to reciprocate the magnet, because the reciprocating unit easily becomes worn, much time is required to maintain and repair the reciprocating unit. However, in the second embodiment of the present invention, because the movement of the magnet36is realized by rotating, it can be smoothly operated and the probability of the apparatus malfunctioning can be markedly reduced. In addition, in the conventional technique, because the scraper is used to separate screws from the magnet, excessive force may be applied to the screws, damaging the screws. As well, the scraper also easily becomes worn. Thus, replacement or repair of the scraper is frequently required. However, in the second embodiment of the present invention, the operation of dropping screws on the guide rail unit4can be smoothly conducted in such a way as to move the magnet36away from the surface of the rear plate23and reduce the intensity of the magnetic force applied to the screws. Hence, it is not required to apply a separate external force to the screws S to remove them from the magnet36. Thus, the screws S can be prevented from becoming damaged, and the apparatus can also be prevented from becoming worn. Moreover, the present invention is provided with the brush rotating unit5. Therefore, screws S or the like can be easily arranged in line by the brush rotating unit5, so that the screws S can be reliably discharged one after another.

Third Embodiment

Hereinafter, an apparatus for feeding screws according to a third embodiment of the present invention will be described in detail with reference to the attached drawings.

Although the screw feeding apparatus according to the third embodiment uses the scooping unit3of the second embodiment, a parallel roller unit is used as a carrying unit, unlike the first or second embodiment using the guide rail unit having the guide groove as the carrying unit.

As shown inFIG. 11, the scooping unit3is provided on an outer surface of a rear plate23of a storage container2in the same manner as that of the second embodiment. In addition, the construction of the scooping unit3is the same as that of the first embodiment. Therefore, detailed explanation of the scooping unit3of the third embodiment will be omitted.

In the third embodiment, a guide plate29is installed on the inner surface of the rear plate23. The guide plate29temporarily receives screws S dropped from the scooping unit3and guides the screws S to the center of carrying rollers71aand71bof the carrying unit7.

The carrying unit using the parallel roller unit7includes the carrying rollers71aand71bwhich are parallel to each other and respectively have spiral grooves72aand72bwhich correspond to each other to form a symmetrical structure. The carrying rollers71aand71brotate in opposite directions. Due to the above-mentioned construction, when the carrying rollers71aand71brotate, the spiral grooves72aand72brotate along with the carrying rollers71aand71bas if they linearly move along the surfaces of the carrying rollers71aand71bin the direction in which the screws S are carried. In the junction between the carrying rollers71aand71b, head parts or front ends of the screws S are held by the edges of the spiral grooves72aand72b, so that when the carrying rollers71aand71brotate, the screws S are carried along the spiral grooves72aand72b. Here, screws S that are not correctly held by the spiral grooves72aand72bat the junction between the carrying rollers71aand71bare removed from the carrying rollers71aand71bby a brush51or a roller guide73and then dropped into the storage container2again. Meanwhile, the screws S that are correctly held by the spiral grooves72aand72bof the carrying rollers71aand71bare guided to a slide path811of a slider81of a discharge unit8and then discharged to the outside in order.

As described above, the screw feeding apparatus according to the third embodiment of the present invention not only has the same operation and effects as those of the first or second embodiment but also may be used to feed relatively large substances so long as the substances are made of magnetic metal even if they have no head parts. In other words, the third embodiment may be used as an apparatus for feeding parts which is superior in terms of compatibility.

Furthermore, the present invention is not limited to the above-mentioned embodiments as long as it does not depart from the scope and spirit of the invention, of course. In addition, partial constructions of the first through third embodiments may be combined with each other. For example, in the first embodiment, the parallel roller unit according to the third embodiment may be used as the carrying unit of the first embodiment. In this case, the guide plate for guiding screws to the roller unit may be provided.

Moreover, because the magnet is used to scoop up screws, the present invention can also be used to feed not only screws but also tacks, rivets or the like having shapes similar to screws, so long as they are magnetic substances.