Patent Grant
11007626
The present application claims priority to Japanese patent application serial number 2017-233679 filed on Dec. 5, 2017, the contents of which are incorporated fully herein by reference.
The present invention relates to a screw-feeding apparatus, such as an autofeed attachment, and to a screw-tightening apparatus, such as a screwdriver.
Japanese Patent No. 4871708 (Patent Document 1) discloses a screw-feeding apparatus 1 of a continuous screw-tightening apparatus 10 that comprises: a base casing 2; a feeder casing 3, which is mounted thereon such that it is movable in a front-rear direction between an interpolated (retracted) state and a protruding (extended) state; and a screw-supplying mechanism 4, which is provided in the interior thereof.
The screw-supplying mechanism 4 comprises, in a front-rear aligned state: a ratchet wheel 4a, which meshes with a band (strip) 9a of a screw-connecting band (screw strip) 9; an intermediate gear 4b, which meshes with the ratchet wheel 4a; and an arm 4c, which is mounted so to be tiltable at a fixed angle with respect to the axial center thereof.
A one-way clutch is formed between the arm 4c and the intermediate gear 4b. In addition, a roller pin 4d is provided on a tilting-tip part of the arm 4c. The roller pin 4d is contained in a slot 2e formed in the base casing 2. A front part of the slot 2e is lower on the front side, and other portions of the slot 2e are oriented in the front-rear direction.
Furthermore, the feeder casing 3 is moved (retracted) to the interpolated (retracted) state as the screw tightening operation is being performed. When the feeder casing 3 is being moved to the protruding state after completion of the screw tightening operation, the arm 4c is reciprocatively tilted by the roller pin 4d, which passes through the slot 2e. Therefore, at the end of the screw tightening operation, the ratchet wheel 4a advances the screw-connecting band 9 by 1 pitch (a single screw 9b) only upward using the one-way clutch and the intermediate gear 4b.
In the screw-feeding apparatus 1 of Japanese Patent No. 4871708, the screw-supplying mechanism 4 comprises the ratchet wheel 4a, the intermediate gear 4b, and the arm 4c in a front-rear aligned (sequentially-disposed) state. Therefore, the screw-supplying mechanism 4 is relatively long in the front-rear direction of the screw-feeding apparatus 1.
In addition, in the screw-supplying mechanism 4 of Japanese Patent No. 4871708, the ratchet wheel 4a, the intermediate gear 4b, and the arm 4c are exposed to the interior of the feeder casing 3. Therefore, dust can enter the feeder casing 3 and adversely affect the operation of the screw-supplying mechanism 4.
Furthermore, in the screw-supplying mechanism 4 of Japanese Patent No. 4871708, there is no disclosure concerning a means for temporarily releasing the one-way clutch; consequently, it is difficult to withdraw the screw-connecting band (screw strip) 9 downward before all of the screws 9b in the screw-connecting band 9 have been used up.
Accordingly, one non-limiting object of the present teachings is to provide a screw-feeding apparatus and a screw-tightening apparatus with screw-feeding apparatus that is more compact (shorter) in the front-rear direction.
In addition or in the alternative, another non-limiting object of the present teachings is to provide a screw-feeding apparatus and a screw-tightening apparatus with screw-feeding apparatus in which durability with respect to dust is improved.
In addition or in the alternative, another non-limiting object of the present teachings is to provide a screw-feeding apparatus and a screw-tightening apparatus with screw-feeding apparatus in which it is possible to easily withdraw the screw-connecting band (screw strip) in the downward direction.
In a first aspect of the present teachings, a screw-feeding apparatus preferably comprises: a base casing that is mountable on a screw-tightening apparatus (e.g., a screwdriver); a feeder casing, which is mounted on the base casing such that it is movable relative to the base casing in a tightening (axial, longitudinal) direction of a screw; a wheel, which is provided inside the feeder casing and is adapted to advance, by rotating in a forward direction, a screw strip (i.e. a plurality of screws coupled by (detachably attached to) a connecting strip); a wheel forward-direction rotating mechanism adapted to rotate the wheel in the forward direction and restrict rotation of the wheel in a reverse direction that is opposite of the forward direction; and a wheel-release (wheel-free) mechanism that releases the restriction placed by the wheel forward-direction rotating mechanism on rotation in the reverse direction. The wheel forward-direction rotating mechanism and the wheel-release mechanism are preferably disposed, at least partially and more preferably at least substantially, inside (in the interior) of the wheel.
In a second aspect of the present teachings, the wheel forward-direction rotating mechanism preferably comprises: a first cam; a second cam connected to the wheel so as rotate therewith and adapted such that the second cam engages the first cam during rotation of the wheel in the reverse direction; and a third cam that is adapted to engage the second cam during rotation of the wheel in the reverse direction. Furthermore, the wheel-release mechanism includes a shaft that is adapted to move at least any two of the first cam, the second cam, and the third cam and separates the first cam and the third cam from the second cam so that the second cam becomes free to rotate in the reverse direction.
In a third aspect of the present teachings, a screw-feeding apparatus comprises: a base casing adapted to be mounted on a screw-tightening apparatus; a feeder casing, which is mounted on the base casing and is movable relative to the base casing in a front-rear direction, which is a tightening direction of a screw; a wheel, which is provided inside the feeder casing such that an (its) axial direction extends a left-right direction and is adapted to advance, by rotating in a forward direction, a screw strip (a plurality of screws coupled by (attached to) a connecting strip); a wheel forward-direction rotating mechanism that rotates the wheel in the forward direction and restricts rotation in a reverse direction; and a wheel-release (wheel-free) mechanism that releases the restriction placed by the wheel forward-direction rotating mechanism on rotation in the reverse direction. The wheel-release mechanism is aligned with the wheel in an up-down direction.
In a fourth aspect of the present teachings, a screw-tightening apparatus has any one of the above-mentioned screw-feeding apparatus mounted thereon.
With regard to the arrangement of the wheel forward-direction rotating mechanism and the wheel-release mechanism inside (in the interior) of the wheel, “at least partially” means that at least 30% of a longitudinal (axial) extension of the wheel forward-direction rotating mechanism and the wheel-release mechanism is disposed (physically exists) between outer edges or outer flanges of the wheel. Furthermore, “at least substantially” means that at least 50% of the longitudinal (axial) extension of the wheel forward-direction rotating mechanism and the wheel-release mechanism is disposed (physically exists) between the outer edges or outer flanges of the wheel, more preferably at least 60%, at least 70%, at least 80% or at least 90% of the longitudinal (axial) extension of the wheel forward-direction rotating mechanism and the wheel-release mechanism is disposed (physically exists) between the outer edges or outer flanges of the wheel.
In addition or in the alternative, the wheel may have a first rotational axis, the wheel forward-direction rotating mechanism may have a second rotational axis (first longitudinal axis) and the wheel-release mechanism may have a second longitudinal axis. The first rotational axis, the second rotational axis (first longitudinal axis) and the second longitudinal axis preferably coincide. Optionally, the wheel-release mechanism may include a shaft that rotatably supports the wheel about the coinciding axes such that the wheel rotates about the shaft. The shaft may be adapted such that movement in its axial direction causes the restriction on rotation in the reverse direction imposed by the wheel forward-direction rotating mechanism to be temporarily released (e.g., as long as the shaft is disposed in an axially-displaced position relative to its axial position when the restriction is placed on rotation of the wheel in the reverse direction.)
According to one or more of the above-mentioned aspects, a screw-feeding apparatus and a screw-tightening apparatus may be designed to be more compact (shorter) in the front-rear direction.
In addition or in the alternative, a screw-feeding apparatus and a screw-tightening apparatus may be designed to be more durable with respect to dust.
In addition or in the alternative, a screw-feeding apparatus and a screw-tightening apparatus may be designed so that a screw-connecting band (screw strip) is more easily detachable (removable) in the downward direction.
Additional objects, embodiments, effects and advantages of the present teachings will be readily apparent to a person skilled in the art after reading the following description and claims in view of the appended drawings.
Embodiments and modified examples of the present teachings are explained below, with reference to the drawings where appropriate.
Front, rear, up, down, left, and right in the embodiments are prescribed for the sake of convenience of explanation and may change in accordance with, for example, the circumstances of the work, the movement of the components, or the like.
The screwdriver 2 serves (acts) as a screw-tightening apparatus and preferably comprises a housing 10, which serves (acts) as a holding body, that directly or indirectly holds (supports) various mechanical components. It is noted that left in
The housing 10 comprises: a motor housing 12, which holds a motor (not shown) that serves (acts) as a motive-power source; a speed-reducing mechanism (not shown), which includes a gear train disposed at a front side of the motor housing 12 that is rotated by a motor shaft of the motor and outputs a reduced rotational speed; and a gear housing 14, which holds a clutch mechanism that switches (engages and disengages) the transmission of torque from the gear train to a spindle 24.
The motor housing 12 has left and right halves and comprises: a motor-housing main body 12a that has a tube shape and extends forward and rearward and in which a motor is disposed. Rearward thereof, a grip 12b has a tube shape and extends downward from a lower part of the motor-housing main body 12a. Air-suction ports 16 are formed in one or both side surfaces of the motor-housing main body 12a. A trigger 18 is partially exposed at a front-upper part of the grip 12b and enables the switch state of a switch (not shown) for controlling the motor to be changed by pulling (squeezing) the trigger 18. A cord-connection part 19 for a power cord (not shown) that supplies electric current to the motor is provided on (at) a lower end of the grip 12b.
The gear housing 14 has a tapered-tube shape and is mounted on a front opening of the motor-housing main body 12a by a plurality of screws 20 being passed through a rear part of the gear housing 14 in the front-rear direction. Air-exhaust ports 22 are provided on one or both side surfaces of the gear housing 14. The above-mentioned spindle 24, which serves (acts) as an output part for driving (tightening) screws, is held inside the front part of the gear housing 14. A bit-mounting hole 24a (
The autofeed attachment 4, which serves (acts) as a screw-feeding apparatus, comprises: a base casing 30; a feeder casing 32, which is disposed in the interior of and forward of the front part of the base casing 30; and a screw strip feeding mechanism 34, which is disposed inside the feeder casing 32.
The base casing 30 comprises: a base-casing main body 30a, which extends in the front-rear direction and has a square columnar shape; and a screw strip guide 30b, which extends downward from the rear part of the base-casing main body 30a in a tapered shape. The base casing 30 has left and right halves, which are joined to one another by screws 30c.
A tubular adapter 36 is fitted in a rear opening of the base-casing main body 30a. The inner surface of the adapter 36 has a circular-tubular shape configured such that it at least partially conforms to the outer surface of the front end of the screwdriver 2. The outer surface of the adapter 36 is formed such that it at least partially conforms to an inner surface of the rear part of the base casing 30. The adapter 36 receives (holds) the front end of the screwdriver 2 to detachably fix the base casing 30 to (on) the screwdriver 2. When fixed in such a manner, the bit of the screwdriver 2 is located in (extends into) the interior of the autofeed attachment 4.
In the interior of the screw strip guide 30b, an arcuate lower-guide groove 38 is formed such that the center of the groove 38 is located forward of the lower end of the motor-housing main body 12a. A discoidal (disc-shaped) depth-adjusting dial 40 is provided in an upper portion of the screw strip guide 30b, which is upward of the lower-guide groove 38. The axial direction (rotational axis) of the depth-adjusting dial 40 is aligned with (extends in) the up-down direction. As shown in
The feeder casing 32 comprises a stopper base 32b mounted on a front end of a feeder box 32a.
The feeder box 32a has left and right halves. An open-cover, box-shaped right part and a cover-shaped left part are joined together by a screw 42. The feeder box 32a is provided so as to be movable in the front-rear direction within (relative to) the base casing 30 by superimposing one or more front-rear-extending rail(s), which is (are) formed on one of the inner surface of the base casing 30 and the outer surface of the feeder box part 32a, on one or more corresponding front-rear-extending groove(s), which is (are) formed on the other. A coil spring 43 extends in the front-rear direction and serves (acts) as an elastic body (urging member). The coil spring 43 extends between the rear part of the feeder box 32a and the front part of the adapter 36 within the base-casing main body 30a, as shown in
In addition, the feeder box 32a has an open part, which is open from a center part of a front surface to a front part of a lower surface, and has J-shaped upper-guide grooves 44 on both sides of the front part of the feeder box 32a. The lower parts of the J-shaped upper-guide grooves are arcuate in a side view and the upper parts of the J-shaped upper-guide grooves extend (straight) in the up-down direction in a side view.
The stopper base 32b has a box shape, which is open at the top, bottom, and rear, and, at its rear part, receives the front part of the feeder box 32a. A screw pass-through slit 45a is formed in the front surface of the stopper base 32b and extends from the center part to the lower part. A cap 46 is made of an elastic body (e.g., rubber or other elastomer) and likewise has a screw pass-through slit 45b. The cap 46 is fitted onto the front side of the front surface of the stopper base 32b. The stopper base 32b may be made available in differing lengths in the front-rear direction, in addition to the one shown in the drawings, so that it can be exchanged in accordance with the length of the screws 52 on a screw strip 50. In the alternative, the stopper base 32b may be configured such that it is linearly movable relative to the feeder box 32a, in order to adjust the front-rear length of the interior of the stopper base 32b (i.e. relative to the feeder box 32a). After the front-rear length is set, it may then be locked in the set axial position during operation of the autofeed mechanism 4.
In the screw strip 50, as partly shown in
Notches (cutouts, through-holes) 56 are disposed at (formed in, penetrate through) both longitudinal sides of the connecting strip 54. The notches 56 are disposed at a pitch or spacing that is the same as the spacing of the holes in the connecting strip 54 for the screws 52 (i.e., at the same pitch/spacing of the screws 52). Each of the notches 56 is disposed midway between the holes of adjacent screws 52 in the longitudinal direction of the connecting strip 54.
The screw strip feeding mechanism 34 is disposed inside the feeder box 32a as shown in
Referring now to
The lever 60 comprises: a front pin 74, which projects rightward from the right part of the front end of the lever 60; a center pin 76, which projects leftward and rightward from a central corner of the lever 60; a rear pin 78, which projects leftward from a leftward portion of a rear end of the lever 60; and a bent part 80, which is formed between the center pin 76 and the rear pin 78.
The center pin 76 is inserted into a hole 82 (see
That is, the sleeve 62 is inserted (placed) onto the rear pin 78 so as to be rotatable relative to the rear pin 78. The sleeve 62 and the rear pin 78 are inserted (disposed) within the groove-shaped lever guide 83, which is formed (defined) in (on) an inner surface of the left part of the base-casing main body 30a, as shown in
The portion of the lever 60 that is located forward of the bent part 80 in the front-rear direction is also located more rightward of the portion of the lever 60 rearward thereof in the front-rear direction. In other words, the bent portion 80 bends to the right so that the rear pin 78 may engage in the groove-shaped lever guide 83 defined in the base-casing main body 30a and the front pin 74 may engage in a groove part 86 of the first cam 64, which is disposed rightward (inward) of the base-casing main body 30a.
The outer dimension (periphery, diameter) of the first cam 64 is larger than the outer dimension (periphery, diameter) of the center hole of the wheel 72. Therefore, the leftward portion of the first cam 64 is disposed outside of the wheel 72 and the rightward facing surface of the first cam 64, which is radially outward of (radially surrounds) first teeth 88, abuts the left-facing surface of the leftward flange 110 of the wheel 72.
A ring-shaped (annular) rib (boss) 84 projects leftward around the center hole on the left-facing surface of the first cam 64. The groove part 86 is defined (disposed) on a rear side of the rib 84. The groove part 86 extends in the front-rear direction and is formed (defined) by two parallel ribs that extend rearward with the left-facing surface of the first cam 64 interposed therebetween. As was noted above, the front pin 74 of the lever 60 is inserted in the groove part 86 while being movable in the front-rear direction when the lever 60 is pivoted about the center pin 76 that is disposed in the hole 82 of the feeder box 32a.
In addition, the above-mentioned first teeth (e.g., 8 teeth) 88 are arranged around the center hole on the right-facing surface of the first cam 64. Each tooth of the first teeth 88 comprises a first steeply inclined surface 88a (the surface in the left-right direction) and a first gently inclined surface 88b. Each first steeply inclined surface 88a is disposed on the counterclockwise side, viewed from the right, of the first gently inclined surface 88b of the same tooth.
The second cam 66 has five protrusions (tabs) 90, which protrude radially outward from the circular-tubular outer surface, namely three protrusions 90 on an upper part and two protrusions 90 on a lower part. The protrusions 90 are arranged such that they do not have rotational symmetry as a whole. Furthermore, five recessed grooves (slots) 92 are formed in (around) the center hole of the wheel 72 so as to extend in the left-right direction and are arranged at complementary (corresponding) locations to the protrusions 90. Because the protrusions 90 and the recessed grooves 92 are disposed (arranged) in a rotationally non-symmetric manner, it is possible to prevent the second cam 66 from being disposed (placed, installed) inside the wheel 72 in the wrong orientation. That is, the protrusions 90 prevent the surface of the second cam 66 having second teeth 94 (see below) from being mistakenly placed facing the right side (i.e. facing away from the first teeth 88) instead of facing the left side (i.e. facing toward the first teeth 88).
As mentioned above, second teeth 94, which are shaped similar to the first teeth 88, are formed on the left-facing surface of the second cam 66. Second steeply inclined surfaces 94a of the second teeth 94 are disposed on the counterclockwise side, viewed from the left, of second gently inclined surfaces 94b of the same tooth.
Furthermore, third teeth 96, which are also shaped similar to the first teeth 88 and the second teeth 94, are formed on the right-facing surface of the second cam 66. Third steeply inclined surfaces 96a of the third teeth 96 are disposed on the clockwise side, viewed from the right, of third gently inclined surfaces 96b of the same tooth.
The leftward part of the third cam 68 has a donut shape, and the rightward part of the third cam 68 has a bottomed tube (blind hole) shape that is narrower (smaller diameter) than the leftward part (see
The rightward part of the third cam 68 is inserted, so as to be movable in the left-right direction, in a cam-receiving part 100 (see
The shaft 70 has a circular-column shape and, at a center part thereof, comprises a large-diameter part 102, which is thicker (larger diameter) than other portions of the shaft 70. Optionally, the outer surface (contour) of at least the rightward extension of the shaft 70 also preferably has a non-circular, e.g., partially flat, cross-section and at least a portion of the inner surface (contour) of the third cam 68 also preferably has a corresponding or complementary non-circular, e.g., partially flat, cross-section, such that the outer surface of the shaft 70 mates or engages with the inner surface of the third cam 68 in an interlocking (form fit) manner, thereby blocking or preventing rotation of the shaft 70 about its central longitudinal axis. In this case, the reverse button 107 will not rotate when the wheel 72 advances the screw strip 50. However, the shaft 70 preferably has a substantially circular cylindrical outer surface to support (permit) rotation of the first cam 64 and the second cam 66 about the shaft 70.
As shown in
The left-end part of the shaft 70 passes through a hole formed in the left part of the feeder box 32a and constitutes a reverse button 107, which is exposed externally (see
The wheel 72 comprises a discoidal (disc-shaped) flange 110 on both the left and right sides of a central circular-tubular part 108. The spacing of the flanges 110 is approximately identical to the width of the connecting strip 54, more specifically slightly narrower than the width of the connecting strip 54. Radially-outwardly-protruding feed teeth 112 are disposed (arranged) on the circular-tubular surface of each flange 110 such that the feed teeth 112 are equispaced in the circumferential direction.
As shown in
Furthermore, a spring 117, which serves (acts) as an elastic body (urging member), extends between the right side of the bearing 116 and the third cam 68 (more specifically, the right-facing surface of the donut-shaped part on the left side of the third cam 68). The spring 117 presses (biases, urges) the teeth of the cams 64, 66, 68 into contact (engagement) when the user is not pressing the reverse button 107.
The left-surface side of the wheel 72 is positioned (held) in the left-right direction by the right-facing surface of the first cam 64 (the flat portion of the first cam 64 that radially surrounds the first teeth 88) and by upper and lower positioning ribs 118, which extend rightward from the inner surface of the left part of the feeder box 32a.
The third cam 68 (or at least the leftward portion thereof), the second cam 66, the right-end part of the first cam 64, and the rightward part of the shaft 70 are disposed inside the center hole of the wheel 72. Among these three cams 64, 66, 68, only the second cam 66 is coupled to (interlocked with) the wheel 72 by engagement (placement) of the protrusions 90 on the second cam 66 in the recessed grooves 92 within the wheel 72. In addition, the third cam 68, the second cam 66, and the shaft 70 are movable in the left-right direction (against the biasing force of spring 117). The first cam 64 is preferably not movable in the left-right direction. As was noted above, the first cam 64 and the second cam 66 are rotatably supported by the shaft 70, whereas the third cam 68 is not rotatable owing to its interlocked engagement with the cam-receiving part 100 defined on (fixedly extending from) the inner surface of the feeder box 32a.
The lever 60, the first cam 64, the second cam 66, and the third cam 68 (along with the lever guide 83) are components of one representative, non-limiting embodiment of a wheel forward-direction rotating mechanism according to the present teachings. In addition, the shaft 70 and the spring 117 are components of one representative, non-limiting embodiment of a wheel-release mechanism according to the present teachings.
An example of the operation of the autofeed screwdriver 1 configured in this manner is explained below, with reference principally to
A user passes an end part of the connecting strip 54 of the screw strip 50, with the screw threads of the screws 52 facing forward, from the lower end to the upper end of the lower-guide-groove 38 of the base casing 30 while the autofeed attachment 4 mounted on the screwdriver 2 is in its extended state (
While the screw strip 50 is being inserted into the feeder box 32a, the first cam 64 is held in a fixed rotational position by the engagement of the front pin 74 of the lever 80 in the groove part 86 of the first cam 64. As shown in
As was noted above, when the connecting strip 54 of the screw strip 50 is inserted into the lower end portion of the upper guide grooves 44, it contacts the flanges 110 (more specifically, the feed teeth 112 thereof) of the wheel 72, thereby rotating the wheel 72 in the forward direction. By rotating the wheel 72 in the forward direction, the screw strip 50 is loaded into operating position in the feeder box 32a because the front-lower portions of the left and right feed teeth 112 enter and engage the corresponding notches 56 of the upper-end part of the screw strip 50. The left and right feed teeth 112 thus transmit the rotational movement of the wheel 72 to the screw strip 50, thereby advancing the screw strip 50 upward when the wheel 72 rotates in the forward direction (i.e. in the direction that loads another screw 52 into the stopper base 32b so that the screw 52 may be driven into the workpiece or work area by the bit).
When the autofeed attachment 4 is in the (its) extended state, the rear pin 78 of the lever 60 is located at the lower end of the lever-guide front part 83a, and the front pin 74 and the groove part 86 of the first cam 64 are located upward, as shown in
With the autofeed attachment 4 in the (its) extended state, the user places the cap 46 on the area (work area) at which a screw 52 is to be screwed into the workpiece and then pushes the screwdriver 2 forward.
This pushing causes the base casing 30 to advance, against the bias force of the coil spring 43, relative to the feeder casing 32, thereby contracting the autofeed attachment 4. As was explained above, the center pin 76 is held in the hole 82 in the feeder case 32a. Therefore, the center pin 76 and thus the lever 60 move rearward relative to the base casing 30 when the autofeed attachment 4 is contracted.
More specifically, as shown in
Therefore, the rotation of the wheel 72 by this amount causes the screw 52 of the screw strip 50 to be advanced (upward) by 1 pitch by the upward movement of the feed teeth 112 that is transmitted to the notches 56 of the connecting strip 54, such that the screw 52 is moved from the (lower) position shown in
It is noted that, when the second cam 66 is rotated in this direction (forward direction), the third steeply inclined surfaces 96a of the third teeth 96 of the second cam 66 move in a direction away from the fourth steeply inclined surfaces 98a and follow the fourth gently inclined surfaces 98b of the fourth teeth 98 of the third cam 68. Therefore, the third teeth 96 of the second cam 66 do not engage the fourth teeth 98 of the third cam 68, such that the third cam 68 permits the rotation of the second cam 66 in the appropriate (forward) direction (a one-way clutch). In other words, when the second cam 66 is rotated in the forward direction, the third gently inclined surfaces 96a of the rotating second cam 66 slide or slip over the fourth gently inclined surfaces 98a of the non-rotating third cam 68 as shown in
In addition, before the front end of the screw 52 is pushed through (exits) the screw pass-through slit 45b of the cap 46, the bit is inserted into the head of the screw 52 that has been moved so as to be axially forward of the bit.
The user then pulls (squeezes) and holds the trigger 18 while pushing the screwdriver 2 forward to cause the bit to rotate and drive the screw 52 into the workpiece. While the screw 52 is being driven (rotated) by the bit, the attitude (pivot position) of the lever 60 does not change, because the front pin 74 is maintained (held) in the (its) descended state owing to the fact that the rear pin 78 is moved into and then moves along in the lever-guide main body 83b that extends straight in the front-rear direction (see also
Thus, the front (thread) part of the screw 52 exits forward through the screw pass-through slit 45b of the cap 46 and is inserted (driven) into the work area while being rotated by the bit. It is noted that, at the start of the forward movement caused by the bit, the screw 52 is forcibly separated from the connecting strip 54 by that forward movement.
After the feeder casing 32 has completely entered the base casing 30 and the autofeed attachment 4 has maximally retracted (
Just before the autofeed attachment 4 completely returns to the (its) extended state, the bit separates from the screw strip 50.
At this time, as shown in
That is, because the spring 117 is biasing the non-rotatable third cam 68 against the right-facing surface of the second cam 66 at this time, the third steeply inclined surfaces 96a of the third teeth 96 of the second cam 66 engage the fourth steeply inclined surfaces 98a of the fourth teeth 98 of the non-rotatable third cam 68. Accordingly, because the third cam 68 is held in the cam-receiving part 100 in a non-rotatable manner, the second cam 66 does not rotate in the counterclockwise direction when the first cam 64 rotates counterclockwise (in the reverse direction), viewed from the left side. As a result, the wheel 72 also does not rotate at this time (rotation of the wheel 72 in the reverse direction is restricted), as shown in
The user may repeat the cycle of compressing of the autofeed attachment 4, passing through the fully retracted state, and returning to the extended state, such that the screws 52 of the screw strip 50 are successively driven into the workpiece or work area. In this embodiment, the screw strip 50 is advanced only upward (forward) and is never advanced downward (rearward) while the spring 117 is biasing the three cams 64, 66, 68 into engagement. In addition, only the connecting strip 54 exits upward, and the screws 52 to be subsequently supplied are disposed downward.
On the other hand, if the user wishes to remove the screw strip 50 midway (i.e. before all the screws 52 have been removed from the connecting strip 54), then the user may simply pull the screw strip 50 upward when a screw is not being tightened, because the second cam 64 can rotate in the forward direction even while the spring 117 is biasing the three cams 64, 66, 68 into engagement.
In the alternative, the user can also remove the screw strip 50 from below (i.e. by pulling downward) by first pushing the reverse button 107, which is the left end of the shaft 70, to permit rotation of the wheel 72 in the reverse (opposite) direction.
More specifically, as shown in
On the other hand, as shown in
As a result, the fourth teeth 98 of the third cam 68 separate (become spaced apart) from the third teeth 96 of the second cam 66, and also the second teeth 94 of the second cam 66 separate (become spaced apart) from the first teeth 88 of the first cam 64, whereby the second cam 66 becomes rotatable in both directions, as can be seen in
Accordingly, in this state (i.e. the reverse button 107 is being pressed rightward in
The autofeed attachment 4 and the autofeed screwdriver 1 of the embodiment described above comprise: the base casing 30, which is mounted on the screwdriver 2; the feeder casing 32, which is mounted on the base casing 30 such that the feeder casing 32 is movable in the tightening (driving) direction of the screw 52; the wheel 72, which is provided inside the feeder casing 32 and causes the screw strip 50, which has a plurality of the screws 52 coupled by the connecting strip 54, to advance when the wheel 72 rotates in the forward direction; a wheel forward-direction rotating mechanism, which rotates the wheel 72 in the forward direction and restricts (blocks) rotation in the reverse direction; and a wheel-release mechanism that releases the restriction placed by the wheel forward-direction rotating mechanism on rotation in the reverse direction. Furthermore, the wheel forward-direction rotating mechanism and the wheel-release mechanism are disposed, at least partially or more preferably at least substantially, inside (in the interior) of the wheel 72.
According to this embodiment, the wheel-release mechanism, which makes it possible to easily reversely withdraw (downwardly remove) the screw strip 50, can be embodied in a relatively compact (short) manner in the front-rear direction and in the up-down direction. Furthermore, the wheel 72 protects (shields) the wheel forward-direction rotating mechanism and the wheel-release mechanism from dust and the like generated by the workpiece (e.g., gypsum board) and the like.
In addition, the wheel forward-direction rotating mechanism of the embodiment described above comprises: the first cam 64; the second cam 66, which is connected to (interlocked with) the wheel 72 and is adapted such that the first cam 64 does not engage and rotate the second cam 66 during rotation of the first cam 64 in the reverse direction; and the third cam 68, which is adapted to engage and block rotation of the second cam 66 in the reverse direction during rotation of the first cam 64 in the reverse direction; furthermore, the wheel-release mechanism comprises the shaft 70, which moves the second cam 66 and the third cam 68 in order to separate (space apart) the first cam 64 and the third cam 68 from the second cam 66.
This design enables the autofeed attachment 4 and the autofeed screwdriver 1 to be made more compact and highly durable with respect to dust and the like and enables the simple reverse withdrawal of the screw strip 50.
It is noted that the present teachings are not limited to the above-described embodiments and modified examples; for example, the following modifications can be implemented as appropriate.
In contrast to the front-rear direction, which is the tightening (driving) direction of the screw 52, or the left-right direction, which is the axial direction of the wheel 72, the wheel-release mechanism may be aligned with the wheel 72 in the up-down direction. For example, instead of disposing the first cam 64, the second cam 66 and the third cam 68 and the shaft 70 and the spring 117 in the interior of the wheel 72, a gear with one-way clutch, which meshes with teeth formed on the circular-tubular part 108 of the wheel 72, may be disposed on an upper side (or lower side) of the wheel 72, so as to be movable in the left-right direction by the wheel-release mechanism in the same manner as the spring 117 and the shaft 70. In such a modified embodiment, the wheel 72 is rotatably supported by a separate central axis substituting for the shaft 70, and the lever 60 may be connected to that gear from the rear (or above or below).
In such an embodiment, the gear with one-way clutch and the lever 60 are components of the wheel forward-direction rotating mechanism.
When the wheel-release mechanism is not moving, the gear with one-way clutch engage the teeth of the wheel 72. On the other hand, the gear with one-way clutch separates (becomes spaced apart) from the teeth of the wheel 72 by the operation of the wheel-release mechanism (the pressing down of the shaft 70), thereby permitting rotation of the wheel 72 in both directions.
In such a modified embodiment of the present teachings as well, the screw strip 50 may be easily withdrawn using the wheel-release mechanism and the autofeed attachment 4 may be designed in a compact manner in the front-rear direction.
The shapes of the teeth of the first cam 64, the second cam 66 and the third cam 68 can be variously modified, and any of the steeply inclined surfaces and gently inclined surfaces may be or may partially include a curved surface. In addition, various types of clutches, such as a friction board, may be used for any one of the one-way clutch of the first cam 64, the second cam 66 and the third cam 68 and the one-way clutch in the above-mentioned modified examples.
The sizes of the notches 56 of the connecting strip 54 and the feed teeth 112 of the wheel 72 may be changed, and the notches and the feed teeth may be reversely configured. This likewise applies to any one pair of the protrusions 90 of the second cam 66 and the recessed grooves 92 of the wheel 72, as well as to the various grooves and the various pins and projections inserted therein.
The shaft 70 may move the first cam 64 and the second cam 66, and the first cam 64, the second cam 66 and the third cam 68 may all be moved.
One or both of the coil spring 43 and the spring 117 may be an elastic body (elastomeric member) of some other type, such as a rubber block. This likewise applies to the cap 46.
One or more of the various components and portions may be configured as one body or as a separate body. For example: the motor housing 12 and the gear housing 14 may be one body; the motor-housing main body 12a and the grip 12b may be separate bodies (the former becoming a motor housing and the latter becoming a grip housing); the reverse button 107 and those portions of the shaft 70 other than the left-end may be separate bodies; and the flanges 110 and the circular-tubular part 108 of the wheel 72 may be separate bodies.
The depth-adjusting dial 40, the depth-adjusting mechanism 41, and the adapter 36 may be omitted. This applies likewise to any one of the various components and portions such as the cap 46, the rib (boss) 84 of the first cam 64, the ring 104, the band 114, and the like.
The connecting strip 54 may be made of a material other than a synthetic resin. Various other materials may be used for other members, such as the felt ring 104.
At least one of the number and arrangement of the air-suction ports 16 can be variously modified. This applies likewise for any one of the trigger 18, the air-exhaust ports 22, the teeth of the first cam 64, the second cam 66 and the third cam 68, the protrusions 90 of the second cam 66 and the recessed grooves 92 of the wheel 72, the large-diameter part 102 of the shaft 70, and the feed teeth 112 of the wheel 72.
Any one of the size and shape of the various members may be variously modified. For example, the lever 60 may be further lengthened, the angles of the corner parts of the lever 60 may be increased (including by 180° or greater) or decreased, and the like.
The types of the various members may be variously modified; for example, the trigger 18 may be configured as a button, the depth-adjusting dial 40 may be configured as an operation (manual) lever, etc.
The motor may include brushes or may be a brushless motor.
Instead of or in addition to the cord-connection part 19, a battery-mounting part, to which a (rechargeable) battery (battery pack or battery cartridge) that supplies electric power to the motor can be mounted, may be provided. In this battery-mounting part, just one battery (battery pack or battery cartridge) may be mountable, or two or more batteries (battery packs or battery cartridges) may be mountable. The battery may be, e.g., any type of lithium-ion battery having a voltage, e.g., of 18-36 V, such as 18 V (max. 20 V), 25.2 V, 28 V, and 36 V; of course, a lithium-ion battery having a voltage that is less than 18 V or exceeds 36 V also may be used; and other types of batteries (battery chemistries) may be used.
In addition, the present teachings can also be suitably adapted to a screw-tightening apparatus other than the screwdriver 2. Furthermore, the present teachings can also be adapted to a screw-feeding apparatus other than the autofeed attachment 4. In addition, the present teachings can also be adapted to a screw-tightening apparatus with screw-feeding apparatus in which the screw-feeding apparatus is inseparably integrated (excepting in the case of extraordinary circumstances, such as a repair) with the screw-tightening apparatus.
In the embodiment shown in the drawings, the cams 64, 66, 68 each have at least one disc surface that extends perpendicular to the rotational axis of the first and second cams 64, 66, which is also the rotational axis of the wheel 72. This rotational axis coincides with a central longitudinal axis of the shaft 70, which supports the rotation of the first and second cams 64, 66, and thus also the wheel 72, and with a central axis of the non-rotatable third cam 68.
The teeth 88, 94, 96 and 98 of the cams 64, 66, 68 each project from the respective disc surface in a direction that is at least substantially parallel to the rotational axes of the cams 64, 66. The steeply inclined surfaces 88a, 94a, 96a, 98a preferably extend at an angle of 80-100° to the disc surface, more preferably at an angle of 85-95°, even more preferably 85-92° and most preferably perpendicular to the disc surface (i.e. parallel to the rotational axis). On the other hand, the gently inclined surfaces 88b, 94b, 96b, 98b extend at an angle of 5-30° to the disc surface, more preferably at an angle of 8-20°, and even more preferably 10-15°.
The teeth 88, 94, 96 and 98 preferably have a sawtooth shape in cross-section, as shown e.g., in
According to such a design, when the spring 117 is biasing the cams 64, 66, 68 into engagement and the first cam 64 is rotated in the forward or first rotational direction (see
Because the axial position of the first cam 64 is substantially fixed (is axially immovable) by the front pin 74 on the left side and the radially-extending surface of the flange 110 of the wheel 72 on the right side, the rotation of the second cam 66 causes the third cam 68 to slightly axially displace (i.e. by approximately the height of the steeply inclined surface 96a of the second cam 66), against the biasing force of the spring 117, in the rightward direction while the third teeth 96 of second cam 66 are moving relative to, and thus slipping over, the fourth teeth 98 of the third cam 68.
On the other hand, when the spring 117 is biasing the cams 64, 66, 68 into engagement and the first cam 64 is rotated in the reverse direction (see
When the spring 117 is not biasing the cams 64, 66, 68 into engagement (e.g. when the shaft 70 is moved/pushed rightward by manually pressing the reverse button 107), the teeth 94, 96 of the second cam 66 will completely disengage from the teeth 88, 98 of both the first cam 64 and the third cam 68 and thus the second cam 66 will “float” therebetween, such that neither the first cam 64 nor the third cam 68 blocks or prevents rotation of the second cam 66 and thus the wheel 72. Consequently, the second cam 66 and thus the wheel 72 are free to rotate in either the forward or reverse direction in this disengaged state.
In the embodiment shown in the drawings, the central longitudinal axis of the shaft 70, the central longitudinal axis (rotational axis) of the first cam 64, the central longitudinal axis (rotational axis) of the second cam 66, the central longitudinal axis (rotational axis) of the wheel 72 and the central longitudinal axis of the third cam 68 all coincide. Therefore, the rotational axis of the wheel 72 intersects the reverse button 107. Consequently, the feeder box 32a may be designed in a relative compact manner in the front-rear direction of the autofeed attachment 4.
Furthermore, because the second cam 66 may be disposed entirely within the left-right dimension of the wheel 72 (i.e. entirely between the two flanges 110 in the left-right direction) and the first cam 64 and the third cam 68 may be disposed at least partially, more preferably at least substantially, within the left-right dimension of the wheel 72 (i.e. partially between the two flanges 110 in the left-right direction), the feeder box 32a also may be designed in a relative compact manner in the left-right direction and/or the up-down direction of the autofeed attachment 4.
The term “cam” has been used to identify elements 64, 66, 68 because the teeth slipping action, which takes place when the first cam 64 is rotated, causes at least the non-rotatable (rotationally-fixed) third cam 68 to axially move rightward against the biasing force of the spring 117, although this axial movement of the third cam 68 is not further utilized. Alternate terms for elements 64, 66, 68 include, but are not limited to, slip cam, slip gear, toothed cam, crown gear, sawtoothed gear, sawtoothed crown gear, and sawtoothed cam.
Representative, non-limiting examples of the present invention were described above in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Furthermore, each of the additional features and teachings disclosed above may be utilized separately or in conjunction with other features and teachings to provide improved autofeed attachments for screwdrivers.
Moreover, combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the above-described representative examples, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.
All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter.
| Number | Date | Country | Kind |
|---|---|---|---|
| JP2017-233679 | Dec 2017 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5904079 | Tsuge | May 1999 | A |
| 7231854 | Kikuchi | Jun 2007 | B2 |
| 7424840 | Huang | Sep 2008 | B1 |
| 20040112183 | Huang | Jun 2004 | A1 |
| Number | Date | Country |
|---|---|---|
| 4871708 | Feb 2012 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20190168363 A1 | Jun 2019 | US |
