JPH08147814A - Reel base moving mechanism for recording and reproducing device of magnetic tape type - Google Patents

Abstract

PURPOSE: To reduce the number of parts and to attain a miniaturization, a low price and small power consumption of a reel base moving mechanism by moving a reel base by means of a motor for driving to rotate the reel base between two positions. CONSTITUTION: A pair of reel bases 30s, 30t are rotated on the upper surface part 25 of the guide supporting space 27 of guide rail members 35s, 35t in accordance with its curvature about the rotational center of the outer peripheral part 37 of the motors for driving the reel base 35s, 35t. The bases are moved between the position with a large interval in which position regulating surfaces 45s, 45t of the bases 30s, 30t are abutted on the positioning pins 45 on the guide rail members 35s, 35t, respectively, and the position with a small interval in which other position regulating surfaces 47s, 47t are abutted on a positioning pin 48s. The upper surface part 33 of the bases 30s, 30t is energized toward a chassis 20 at the position with a large interval and the position with a small interval by means of leaf springs 28, 29. The pair of bases 30s, 30t are rotated while being located at symmetric positions by means of the output of a transmission mechanism for moving the reel base.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape type recording / reproducing apparatus for two types of cassettes (two types of tape cassettes having different center intervals between a pair of reels). The present invention relates to a reel base moving mechanism that varies a reel base center interval in a reproducing device.

[0002]

2. Description of the Related Art In a video tape recorder (hereinafter referred to as "VTR"), a pair of reel bases are linearly arranged in order to use a plurality of types of tape cassettes having different reel center distances. There is one that is provided with a reel table moving mechanism for moving to. An example of such a conventional technique is the technique disclosed in Japanese Patent Laid-Open No. 2-270152. The structure of a conventional reel stand moving mechanism of this type is shown in FIG.
And FIG. 6 will be described.

FIG. 5 is a plan view of the reel base moving mechanism, and FIG. 6 is a cross-sectional view of an essential part of FIG. As shown in FIGS. 5 and 6, a pair of guide shafts 2s and 2t are provided on the upper surface of the chassis 1 in a substantially eight shape, and the guide rail shafts 2s and 2t are arranged in parallel with each other. 3s and 3t are provided, respectively. A guide shaft insertion hole 6 is provided in each one side of the pair of reel bases 5s and 5t, and the pair of guide shafts 2s and 2t are inserted therein. Further, a cylindrical roller 8 is engaged with a guide guide groove 7 on each of the other side portions of the pair of reel bases 5s and 5t, and the pair of guide rail shafts 3 are inserted into a center hole 8a of the cylindrical roller 8.
s and 3t are inserted respectively.

The pair of reel bases 5s and 5t are
A worm 14 attached to the rotating shaft of the motor 13,
A pair of worm wheels 15s, 15t and link 1
The pair of reel bases 5s and 5t are connected to each other by the rotation of the motor 13 as shown in FIG.
The linear movement is made between two positions, a large distance position indicated by the solid line and a small distance position indicated by the two-dot chain line.
Also, on the lower surface side of the pair of reel bases 5s, 5t,
The reel base driving motors 10 are fixed, and the reel base 12 is attached to the rotary shaft 11 of the reel base driving motor 10.
s and 12t are attached respectively.

[0005]

As described above, in the prior art, since the reel bases 5s and 5t are moved between the two positions, the dedicated motor 13 and the transmission mechanism are required. Therefore, there is a problem that the number of parts of the device increases, which becomes a factor that hinders downsizing and cost reduction of the device.

Therefore, the technical problem to be solved by the present invention is to eliminate the above-mentioned problems of the prior art, and the purpose thereof is to specialize in moving the reel base between two positions. The motor that removes the motor is used, and this drive is also used as a motor that drives the reel base to rotate, so that the number of parts is reduced, thus making it possible to reduce the size of the device, reduce the cost, and reduce the power consumption. To provide a mechanism.

[0007]

In order to achieve the above object, a reel base moving mechanism according to the present invention comprises a pair of third gears rotatably and movably held on a chassis, and a third gear. Second drive means for moving the gear of the reel base, a reel base that integrally has a gear portion concentric with the rotation center axis thereof, and a gear of the reel base provided coaxially with the rotation center axis of the reel base. A second gear that meshes with the portion, and a first drive means for rotating the second gear, and a third gear
A first position in which the third gear meshes with the second gear and a gear portion integral with the reel base at the same time with a second position that does not mesh at all or only one gear or gear portion. It is configured to move to and from a position.

[0008]

In the reel stand moving mechanism having the above-described structure, in order to move the reel stand from the large gap position to the small gap position or from the small gap position to the large gap position, the third gear is moved to the first gear position. The reel stand can be moved by moving the reel stand to the position and transmitting the driving force of the first driving means from the second gear to the third gear and the gear part integral with the reel stand base. . Therefore, the reel base can be moved by the rotation driving motor of the reel base without using a dedicated drive source for moving the reel base between the two positions, and the number of parts can be reduced. It is possible to reduce the size of the device, reduce the price, and reduce the power consumption.

[0009]

The details of the present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a plan view of a reel base moving mechanism of a VTR according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA of FIG. 1. In these drawings, the supply side and the winding side are shown. Corresponding members have the same reference numerals suffixed with s and t (s on the supply side and t on the winding side), respectively, as required.

As shown in FIGS. 1 and 2, a pair of guide rail members 21s and 21t are arranged on the upper surface of the chassis 20, and the pair of guide rail members 21s and 2t are arranged.
1t is screwed into the chassis 20 with screws 22, 23 and 24 respectively.
It is fixed to. The pair of guide rail members 21
A lower surface portion 25 and an upper surface portion 26 are formed at s and 21t, and a guide support space 27 is formed between the lower surface portion 25 and the upper surface portion 26. On the upper surface portion 26 of each guide rail member, leaf springs 28 and 29 are provided at locations where the center spacing of the reel stand corresponds to the large spacing position and the small spacing position, respectively. Also, a pair of reel bases 30s, 30t having gear portions 32s, 32t concentric with the rotation center axis are arranged on the chassis 20, and at the center of rotation, with respect to the chassis reference plane. A vertical insertion hole 31 is provided.

On the other hand, on the lower surface of the chassis 20, a pair of reel stand drive motors 35s and 35t are provided at positions where the center intervals of the reel stands are equal to each other from two positions, a large gap position and a small gap position. The reel motor assembly 34 provided is fixed. Then, the outer peripheral portion 37 of the housing above the reel base driving motors 35s and 35t.
And the insertion holes 31 of the reel bases 30s and 30t.
Are rotatably engaged.

Therefore, the pair of reel bases 30s, 3
0t is the guide rail member 2 with the housing outer peripheral portion 37 of the reel base driving motors 35s and 35t as the center of rotation.
On the upper surface portion 25 of the guide support space 27 of 1s, 21t,
While the legs 43, 44 on the lower surface of the reel bases 30s, 30t slide, they rotate according to the curvature of the guide rail member, and the position regulating surface 45 of the reel bases 30s, 30t.
A large gap position (s) where s and 45t come into contact with the positioning pin 46 on the guide rail members 21s and 21t, respectively (solid line position in FIG. 1), and a small gap position where other position regulating surfaces 47s and 47t come into contact with the positioning pin 48 ( (Two-dot chain line position in Figure 1)
To move between. Further, at the large interval position and the small interval position, the reel bases 30s, 3 are provided by the leaf springs 28, 29 provided on the guide rail members 21s, 21t.
The upper surface portion 33 of 0t is urged toward the chassis 20. The pair of reel bases 30s and 30t rotate while both are positioned at the target position by the output of the transmission mechanism for moving the reel base.

For example, when the pair of reel bases 30s and 30t rotate from the small interval position (the position indicated by the two-dot chain line in FIG. 1) to the large interval position (the position indicated by the solid line in FIG. 1), each position regulating surface 4
The 5s and 45t come into contact with the positioning pin 46, stop at that position, and are positioned at the large spacing position. Further, at this time, the reel bases 30s and 30t are connected to the guide rail member 21.
The posture is accurately determined by the biasing force of the leaf spring 28 of s, 21t, the legs 43, 44, and the pivot point 56. The rotation from the large-interval position to the small-interval position is also performed in substantially the same manner.

On the other hand, a pair of reel bases 30s,
Reel stands 60s and 60t are respectively arranged on the 30t, and the pair of reel stands 60s and 60t are rotatably supported on the reel stand bases 30s and 30t by rotating shafts 61s and 61t. The reel bases 60s and 60t are integrally formed with tooth portions 62s and 62t that are concentric with the rotation center axis thereof. The tooth portions 62s and 62t are fixed to the output shafts of the reel base drive motors 35s and 35t. Is
And the gear portion 32 of the reel base 30s, 30t
It meshes with intermediate gears 63s and 63t having the same diameter as s and 32t. Therefore, the reel base drive motors 35s, 35
The output of t is transmitted to the reel stands 60s and 60t via the intermediate gears 63s and 63t. Further, arms 68s, 6 are mounted on the chassis 20 so as to be rotatable in synchronization with each other.
8t is provided, and a pair of gears 65s and 65t are rotatable on the arms 68s and 68t so that they can mesh with the intermediate gears 63s and 63t and the gear portions 32s and 32t on the reel stand base at the same time. Held in. Then, the force from the drive source (not shown) (in this embodiment, the force of the tape loading motor is used) is transmitted to the arms 68s and 68t by the drive pin 67.

The above-mentioned pair of reel bases 30s, 3
The reel bases 60s and 60t on 0t rotate and move together with the respective reel bases 30s and 30t, and at the large interval position, the center interval of the pair of reel bases 60s and 60t is the center of the pair of reels of the large cassette. At intervals, and 1 at small intervals
The center distance between the pair of reel bases 60s and 60t matches the center distance between the pair of reels of the small cassette.

The operation of this embodiment will be further described below.
Now, when the pair of reel stands 60s and 60t are in the small interval position shown by the chain double-dashed line in FIG. 1, when the large cassette is inserted from the cassette insertion port and the large cassette is detected, the arm 68s, 68t rotates in the direction of arrow B, and the gears 65s and 65t on the arm move to the intermediate gears 63s and 63t.
t and the gear parts 32s and 32t of the reel base at the same time mesh with each other. Then, the reel base driving motors 35s, 3
When 5t is activated, the reel base drive motors 35s, 35s
The rotational force of t is from the intermediate gears 63s and 63t to the gear 65.
s, 65t, and gear parts 32s, 32t integrated with the reel bases 30s, 30t.

When the rotational force is transmitted to the gear portions 32s and 32t as described above, the reel bases 30s and 30t are provided.
Rotates about the housing outer peripheral portion 37 of the reel base driving motors 35s and 35t as a rotation center, and the reel bases 60s mounted on the reel bases 30s and 30t.
60t is rotated (moved) from the small interval position shown by the two-dot chain line in FIG. 1 to the large interval position shown by the solid line. After the movement of the pair of reel stands 60s, 60t is completed, the large cassette descends from above the pair of reel stands 60s, 60t by a predetermined cassette loading operation, and the pair of reels of the large cassette is reeled by the reel stands 60s, 60t. Are attached to each. When this mounting is completed, the arms 68s and 68t rotate again, and the gears 65s and 65t move to the intermediate gears 63s and 6t.
After separating from the gear parts 32s and 32t of the base 3t and the reel base, tape loading is performed. Next, when each traveling mode is selected, the reel base driving motor 35
s, 35t rotates at a predetermined speed. This rotational force is transmitted to the intermediate gears 63s, 63t, and the reel base 60s,
It is transmitted only to 60t and each rotates at a predetermined speed.

When the pair of reel stands 60s and 60t are in the large-interval position shown by the solid line in FIG. 1, when a small cassette is inserted from the cassette insertion port, it is detected that it is a small cassette. Similarly, it is rotated (moved) to the small interval position shown by the chain double-dashed line in FIG. Then, in the same manner as described above, the pair of reels of the small cassette is connected to the reel stands 60s, 60
and the reel base driving motors 35s,
The reels 60s and 60t are rotated by the driving force of 35t.

As described above, in this embodiment, the reel base driving motors 35s and 35t also serve as the drive source for moving the reel base between the two positions, so that a dedicated motor for moving the reel base is provided. Therefore, the number of parts can be reduced, and the device can be downsized, the cost can be reduced, and the power consumption can be reduced.

FIG. 3 is a plan view of the reel base moving mechanism of the VTR according to the second embodiment of the present invention, and FIG. 4 is a sectional view taken along the line A--A of FIG. Corresponding members on the take-up side have the same reference numerals suffixed with s and t (s on the supply side and t on the take-up side), respectively, as required. Further, in FIGS. 3 and 4, members and parts equivalent to those in FIGS. 1 and 2 are designated by the same reference numerals.

This embodiment is different from the first embodiment described above in that instead of using a pair of reel base driving motors 35s and 35t, one reel base driving motor 74 drives the intermediate gears 63s and 63t. The reel bases 30s, 3 are provided because they are selectively (alternatively) rotated.
The other structure including the 0t rotational force transmission mechanism is basically the same as that of the first embodiment. That is, the reel base driving motor 74 is fixed to the upper surface of the chassis 20,
The output shaft of the reel base driving motor 74 is the chassis 20.
The pulley 73 is fixed to the output shaft of the output shaft. Further, a swing arm 70 is arranged between the pair of intermediate gears 63s and 63t.
One end of 0 is pivotally supported by the chassis 20 together with the subordinate pulley 71. Furthermore, a timing belt 72 is wound between the subordinate pulley 71 and the pulley 73, and a gear (not shown) integrally formed with the subordinate pulley 71 is attached to the swinging arm 70 so that the swinging arm 70 can freely rotate. A gear 75 axially supported on the end side is meshed, and this gear 75 can mesh with one of the pair of intermediate gears 63s, 63t.

On the upper surface of the chassis 20, a slide plate 76 which is capable of linearly reciprocating is arranged. A U groove 80 is formed on the slide plate 76, and a swing arm restricting member 77 for restricting the position of the swing arm 70 is engaged with the U groove 80. Further, the central shaft 79 of the gear 75 pivotally supported by the swing arm 70 is arranged in the U-shaped restricting portion of the swing arm restricting member 77. Therefore, the slide plate 7
The swinging arm restricting member 77 rotates in accordance with the linear movement of 6, and the position of the swinging arm 70 can be controlled.

Auxiliary arms 78s and 78t are provided on the movement restricting shaft of the slide plate 76, and the auxiliary arms 78s and 78t are engaged with the arms 68s and 68t that pivotally support the gears 65s and 65t, respectively. . Further, the slide plate 76 is provided with position regulating surfaces 81, 82, 83, 84 which stand in a direction perpendicular to the chassis 20, and the position regulating surfaces 82, 83 are used for the auxiliary arm 78s.
The position regulating surfaces 81 and 84 can contact the auxiliary arm 78t, and the gears 65s and 65t can be connected to the intermediate gear 63.
s, 63t and gear parts 32s, 3 on the reel stand base
Control is performed such that the 2t is meshed with or separated from the gear.

Then, the force from the drive source (not shown) (in this embodiment, the force of the tape loading motor is used) is transmitted to the slide plate 76 by the drive pin 67.

Depending on the operating position of the slide plate 76, the swing arm restricting member 77 is restricted in three ways. The first position indicated by the chain double-dashed line in FIG. 3 is a position for driving the reel stands 60s, 60t, and at this time, the gears 65s, 65t are moved by the slide plate 76 to the intermediate gears 63s, 63t and the reel stand base. The position is regulated so as not to mesh with the upper gear portions 32s and 32t.

Therefore, the rotational force from the reel base driving motor 74 is transmitted through the pulley 73, the timing belt 72, the subordinate pulley 71, and the gear 75 on the swing arm 70.
It is selectively transmitted to one of the pair of intermediate gears 63s and 63t, whereby one of the pair of reel stands 60s and 60t is selectively rotated.

For example, the reel base driving motor 74 is shown in FIG.
3 rotates in the same direction, the pulley 73, the timing belt 72, and the subordinate pulley 71 also rotate in the same direction. Therefore, due to the moment of the rotational force of the subordinate pulley 71, the swing arm 70 moves in the direction of the arrow Q in FIG. The gear 75 on the swing arm 70 meshes with the intermediate gear 63t on the winding side. Therefore, in this case, the rotational force from the reel base driving motor 74 is applied to the reel base 60t via the pulley 73, the timing belt 72, the subordinate pulley 71, the gear 75 on the swing arm 70, and the intermediate gear 63t. Is transmitted. Similarly, when the reel base driving motor 74 rotates in the direction opposite to the arrow P direction, the gear 75 on the swing arm 70 meshes with the tooth portion of the intermediate gear 63s on the supply side. The rotational force from 74 is the pulley 73, the timing belt 72, the subordinate pulley 71, the gear 75 on the swing arm 70, and the intermediate gear 63.
It is transmitted to the reel stand 60s via s.

Also, a pair of reel bases 30s, 30
In order to move the reel bases 60s and 60t together with t between the large distance position and the small distance position, the slide plate 76 is moved in the B or C direction in FIG. 3 to move the arms 68s and 68t in a predetermined direction. The gears 65s and 65t on the arm are simultaneously meshed with the intermediate gears 63s and 63t and the gear portions 32s and 32t on the reel base. When the reel base driving motor 74 rotates in one direction in this state, the rotation of the reel base driving motor 74 is transmitted from the gear 75 on the swing arm 70 to one of the intermediate gears 63s, 63t, Via one of the corresponding gears 65s, 65t on one arm, either one of the corresponding reel stand bases 30s, 30t
It is transmitted to gear parts 32s and 32t that are integral with t, and either one of the reel bases 30s and 30t is transferred in the same manner as above.
Moves between a large distance position and a small distance position.

For example, to move the supply-side (s-side) reel base 30s from the large-interval position to the small-interval position,
First, slide the slide plate 76 in the C direction,
The swinging arm restricting member 77 is rotated to the second position shown by the solid line in FIG. 3 to move the swinging arm 70 to the intermediate gear 63s.
Mesh with. As described above, the gear 65s is meshed with the intermediate gear 63s and the gear portion 32s on the reel base at the same time by the slide plate 76.
When the reel base driving motor 74 is rotated in the P direction in this state, the rotational force of the motor 74 is changed by the pulley 73, the timing belt 72, the subordinate pulley 71, the gear 75 on the swing arm 70, the intermediate gear 63s, and the gear. Since it is transmitted to the gear portion 32s on the reel stand base via 65s, the reel stand base 30s is moved from the large gap position to the small gap position. On the contrary, in order to move the reel base 30s from the small gap position to the large gap position, the reel base driving motor 74 may be rotated in the direction opposite to P.

The reel base 30t on the winding side (t side) can be moved in the same manner as described above. At this time,
The position of the swing arm restricting member 77 rotates to the position shown by the dotted line in FIG.

As described above, in this embodiment, the pair of reel bases 30s and 30t cannot be moved at the same time, and they are sequentially moved in time series. Since the single reel base drive motor 74 is used to move the bases 30s and 30t,
The drive source can be reduced, and the space factor of component placement is improved.

In the above-described embodiment, the gears 65s and 65t on the arms 68s and 68t are moved in the direction orthogonal to their rotation axes to switch the gear coupling on and off. Upper gear 65s, 65t
May be moved in the direction along the rotation axis (thrust direction) to switch the gear coupling on / off.
Also, the gears 65s, 65t on the arms 68s, 68t
Is a two-stage gear in which a large gear and a small gear are integrated, and gear parts 32s and 32t integral with the reel bases 30s and 30t are described above so that the intermediate gears 63s and 63t mesh with the large gear. The diameters of the intermediate gears 63s and 63t may be different from the diameters of the gear portions 32s and 32t so as to mesh with the small gears, and the reduction ratio may be increased.

[0033]

As described above, according to the present invention, the reel base is moved by the motor for rotationally driving the reel base without using a dedicated drive source for moving the reel base between the two positions. Therefore, the number of parts can be reduced, and the device can be downsized, the cost can be reduced, and the power consumption can be reduced.

[Brief description of drawings]

FIG. 1 is a plan view showing the configuration of a reel base moving mechanism of a VTR according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a plan view showing the configuration of a reel base moving mechanism of a VTR according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is a plan view showing a configuration of a reel base moving mechanism of a VTR according to a conventional example.

6 is a cross-sectional view of the main parts of FIG.

[Explanation of symbols]

 20 chassis 21s, 21t guide rail member 22, 23, 24 screw 25 lower surface part 26 upper surface part 27 guide support space 28, 29 leaf spring 30s, 30t reel stand base 31 insertion hole 32s, 32t gear part of reel stand base 33 reel stand Upper surface of the base 34 Reel motor assembly 35s, 35t Reel stand driving motor 37 Outer housing part of reel stand driving motor 43,44 Reel stand base foot 45s, 45t Position regulating surface for large gap position 46 For large gap position Positioning pins 47s, 47t Position regulating surface for small space position 48 Positioning pin for small space position 56 Rotation fulcrum of reel base 60s, 60t Reel base 61s, 61t Rotation shaft 62s, 62t Tooth portion 63s of reel base, 63t intermediate gear 65s, 65t gear 67 drive 68s, 68t Arm 70 Swing arm 71 Dependent pulley 72 Timing belt 73 Pulley 74 Reel stand drive motor 75 Gear wheel 76 Slide plate 77 Swing arm restriction member 78s, 78t Auxiliary arm 79 Central axis 80 U groove 81, 82, 83,84 Position regulation surface

Claims (8)

[Claims] 1. A pair of reel stands rotatably held on a pair of reel stand bases, and an interval between the pair of reel stands is a reel interval of a small cassette and a reel interval of a large cassette. A pair of reel bases rotatably provided with respect to the chassis so as to change correspondingly, and a first gear that is concentric with the rotation center of each reel base and is integral with each reel base. A second gear that is rotatably held coaxially with the center of rotation of each reel base and that meshes with the first gear; and a first drive unit that rotates the second gear. A magnetic tape type recording / reproducing apparatus for two types of cassettes, large and small, comprising: a gear portion concentric with the rotation center of each reel base and integral with each reel base; Holds freely and movably Paired third gears, a first position in which each of the third gears simultaneously meshes with the second gear and the gear portion integral with the reel base, and the second gear and Second drive means for moving between a second position that does not mesh at all with the gear portion integrated with the reel base or only one gear or gear portion, and the third gear is provided. When in the second position, the reel base is rotated by the first drive means, and when the third gear is in the first position, the reel base is rotated by the first drive means. The reel base moving mechanism of the magnetic tape type recording / reproducing apparatus is characterized in that: 2. The reel base moving mechanism of the magnetic tape type recording / reproducing apparatus according to claim 1, wherein the second gear and the gear portion integral with the reel base are formed to have the same diameter. . 3. The gear according to claim 1, wherein the third gear is a two-step gear in which a large gear and a small gear are integrated, and the second gear is a large gear and the reel base. A reel stand moving mechanism of a magnetic tape type recording / reproducing apparatus, wherein a diameter of the second gear is different from a diameter of the gear portion so that the gear portion meshes with a small gear. 4. The reel stand for a magnetic tape type recording / reproducing apparatus according to claim 1, wherein the moving direction of the third gear is a direction orthogonal to the rotation center axis of the third gear. Moving mechanism. 5. The reel stand of a magnetic tape type recording / reproducing apparatus according to claim 1, wherein the moving direction of the third gear is a direction along a rotation center axis of the third gear. Moving mechanism. 6. The first drive means according to claim 1, wherein the first drive means is two motors that fix the second gears to their output shafts and directly drive the second gears. Reel stand moving mechanism of magnetic tape type recording / reproducing device. 7. The first drive means according to claim 1, wherein the first drive means is a motor and rotation transmission means for selectively transmitting the rotation of the motor to one of the pair of second gears. A reel base moving mechanism of a magnetic tape type recording / reproducing apparatus characterized by the above. 8. The rotation transmission means according to claim 7, wherein the rotation transmission means includes a rotatable arm, and a rotation member having a gear portion coaxial with a rotation center of the arm.
A fourth gear that meshes with a gear portion of the rotating member and is axially supported by one end of the arm, the rotating member is rotated by transmitting the rotation of the motor, and the arm is The fourth gear is selectively rotated into respective positions in which the fourth gear meshes with the respective second gears in the pair, and further, the respective positions in which the fourth gear meshes with the respective second gears. A reel base moving mechanism of a magnetic tape type recording / reproducing apparatus, further comprising a holding means for holding the arm.