JPH0743801Y2 - Optical disk drive - Google Patents

Description

[Detailed Description of the Invention] [Field of Use of the Invention] The present invention relates to an optical disk drive device for reading and writing records on an optical disk such as a compact optical disk, and more particularly to an optical disk storage device. Optical disk drive having a movable tray.

[Background of the invention]

Recently, I have a tray for storing optical discs, and move this tray until the optical disc is located above the table,
Although an optical disk drive device has been developed which performs recording / reading / writing of an optical disk via a laser beam,
In the conventional optical disk drive device, the operation of holding the tray immovable after reading the predetermined record and moving it to the writing position, and lowering the optical disk stored in the tray onto the above table, Since various interlocking operations such as rotatably gripping operation and operation of moving the tray to a position where it can be taken out by lifting the optical disk from the table are required, the number of drive members is large and the structure is complicated. Therefore, the manufacturing cost tends to increase. In addition, since the number of members is large and the structure is complicated, a large arrangement space is required, and therefore the overall external dimensions are likely to be large.

[Purpose of device]

The present invention has been made in view of the actual situation in the prior art as described above, and an object thereof is to be able to favorably realize the reading of the record of the optical disc or the writing of the record to the optical disc, and the number of members. An object of the present invention is to provide an optical disk drive device capable of suppressing the above.

[Outline of device]

In order to achieve this object, the present invention provides a tray in which an optical disc is housed, which is movable toward and away from the main body, a cam which interlocks with a positioning operation of the tray in the main body, and a cam And a disk gripping / releasing means for rotatably gripping the optical disk housed in the tray and releasing the gripping, and the disk gripping / releasing means is a table on which the optical disk can be placed. A wheel that is disposed so as to face the table and that can come into contact with the optical disk, and an arm that holds the wheel and that can rotate in a direction toward and away from the optical disk stored in the tray. A lever that is rotatably provided in a direction that engages with the arm and a direction that separates from the arm and that rotates in conjunction with the cam; And a second spring biasing the lever so that the lever engages with the cam, and a second spring biasing the lever so that the lever engages with the cam. The lever and arm are rotated to bring the wheel into and out of contact with the optical disk, and at the time of this gripping operation, the lever and arm are rotated against the spring force of the spring, and the lever is gripped after the disk is gripped. Only the arm is configured to rotate against the first spring.

[Example of device]

An embodiment of the optical disk drive device of the present invention will be described below with reference to FIGS. 1 to 9 (a), (b) and (c).

FIG. 1 is a plan view showing a state before mounting the optical disc, FIG. 2 is a rear view showing a state before mounting the optical disc, and FIG. 3 is a plan view showing a state when positioning the tray in the main body.

In these figures, 1 is a chassis forming the main body, 2
Is an optical disc, for example, a compact optical disc (shown in FIG. 3), 3 is a tray that can be moved toward and away from the chassis 1, and is a circular recess 4 in which the compact optical disc 2 can be stored. And a notch 4'to which a table and a spindle, which will be described later, and a laser head (not shown) can be inserted. Numerals 5 and 6 are slide rails mounted on both ends of the tray 3 and slidable on the chassis 1, and numeral 7 is a stopper mounted on one slide rail 6 for positioning the tray 3 in the chassis 1. 8 is a rack mounted on the slide rail 6, the second
Reference numeral 9 shown in the figure is a gear engaged with the rack 8, and 10, 11, 12 are also gears. The gear 10 has a small diameter gear portion 13 engaged with the gear 9 and a large diameter gear portion 14, 11 is the large-diameter gear part of gear 10 14
Has a small-diameter portion 15 and a large-diameter gear portion 16 that engage with, the large-diameter gear portion 16 of the gear 11 engages the gear 12, and the gear 12 is a motor.
It is mounted on 17 output shafts.

Slide rails 5, 6, rack 8, gears 9, 10, 11, 1 described above
2, and the motor 17 constitute a tray moving means for moving the tray 3.

Also, there are 18 cams, which are shown in FIGS. 4 (a) and 4 (b).
As shown in, the plate-shaped first cam portion formed in the central portion
19 and a second portion formed on the upper portion of the first cam portion 19.
It is composed of 20 and a gear portion 21 formed in the lower part of the first cam portion 19, and is rotatably mounted on a shaft 22 fixed to the chassis 1. The first cam portion 19 has a large diameter portion 23 and a small diameter portion 24.
And the stopper portion 25 and the recessed portion 25 connected to the stopper portion 25.
The second cam portion 20 has a low portion 26 and a high portion 27 having different height positions, and the cam characteristics of the second cam portion 20 are as shown in FIG. 4C, for example. Is set to. The gears 28, 29, 30, 31 shown in FIG. 2 have a small diameter gear portion 32 that engages with the gear portion 21 of the cam 18 and a large diameter gear portion 33. The small-diameter gear portion 34 that engages with the large-diameter gear portion 33 of the gear 28, and the large-diameter gear portion 35, and the gear 30 includes the small-diameter gear portion 36 that engages with the large-diameter gear portion 35 of the gear 29, and the large-diameter gear portion 35. A gear portion 37, the gear 31 engages with the large-diameter gear portion 37 of the gear 30,
It is mounted on 38 output shafts.

The gears 28, 29, 30, 31 and the motor 38 constitute cam drive means for rotating the cam 18.

Further, 39, 40 and 41 are levers, of which the lever 39 is rotatably mounted on a shaft 42 fixed to the chassis 1, and a roller 43 which engages with the first cam portion 19 of the cam 18, FIG. 8 (c),
As shown in (d), it has a protrusion 45 that can be engaged with the notch 44 formed in the slide rail 5, and locks the tray 3 immovably in conjunction with the rotation of the cam 18. A tray lock / release means for releasing this lock is configured.

The lever 40 is rotatably mounted on a shaft 46 fixed to the chassis 1, and has a roller 47 that engages with the first cam portion 19 of the cam 18, and the lever 41 rotates about the shaft 46. It has a roller 48 that is movably mounted and that engages with the first cam portion 19 of the cam 18, and an overhang portion 51 that can turn the switches 49 and 50 on and off.

In addition, 52 and 53 are switches arranged in parallel with the switches 49 and 50,
These four switches 49, 50, 52, 53 are held in a bracket 54 fixed to the chassis 1. The above-mentioned stopper 7 is engageable with the stopper 54a formed in the bracket 54 as shown in FIGS. 8 (b) to (d), and the switch 53 can be turned on / off.

Also, 55 shown in FIGS. 1 and 3 has one end attached to the lever 39,
A spring, the other end of which is attached to the lever 40, biases the levers 39 and 40 so that the rollers 43 and 47 engage with the first cam portion 19. 56 is also a spring, one end of which is attached to the lever 41 and the other end of which is attached to a rising portion 57 formed on the side portion of the bracket 54,
The lever 41 is urged so that the roller 48 engages with the first cam portion 19.

Reference numeral 58 is a lever capable of turning the switch 52 on and off, and is rotatably mounted on a shaft 59 fixed to the chassis 1. One end of the lever 60 is rotatably connected to the lever 39, and the other end thereof is connected to the lever 58.
Is a connecting rod that is movably connected to.

Further, 61 is a slide support slidably provided on the slide rail 5, and as illustrated in FIGS. 5 to 7,
The above-mentioned overhanging portion 62 with which the lever 40 can be engaged, the spring engaging portion 63, the two inclined holes 64 and 65, and the elongated hole 6 extending in the horizontal direction.
It has 6,67. Mao, 68,69 shown in FIG. 5 to FIG.
Is a shaft fixed to the slide rail 5, and is engaged with each of the elongated holes 66 and 67 so as to be relatively movable. With 70 springs,
One end is engaged with the spring engagement portion 63 of the slide support 61,
The other end is engaged with a protrusion 71 fixed to the slide rail 5.

Reference numeral 72 denotes a disk support, which is a plate-shaped substrate 73 as shown in FIG. 2, rising portions 74, 75 and 76 formed by bending three portions on the side of the substrate 73, and projecting onto the substrate 73. It has three indicator parts 77, 78, 79 which are installed and can indicate the compact optical disk 2. The shafts 80, 81 fixed to the rising parts 74, 75 are in the inclined holes 64, 65 of the slide support 61. Engaged in relative movement. Further, the three support portions 77, 78, 79 can project from the holes 4a, 4b, 4c formed in the circular recess 4 of the tray 3.

Reference numerals 82 and 83 shown in FIG. 2 denote connecting links, of which one end is relatively rotatably engaged with a shaft 84 fixed to the chassis 1 and the other end is relatively rotatable with respect to the shaft 80. The connecting link 83 is movably engaged, one end of which is relatively rotatably engaged with a shaft 85 fixed to the chassis 1, and the other end of which is a substrate 73 via a shaft 86.
Is relatively rotatably engaged with the rising portion 76.

In addition, 87 shown in FIGS. 1 to 3 and 9 (a) is a table on which the compact optical disc 2 can be placed, 88 is arranged at the central position of the table 87, and has a taper on the periphery,
The table 87 is a spindle capable of sinking with respect to the table 87, and the table 87 is rotated by a motor 89 shown in FIG. Reference numeral 90 shown in FIG. 2 is a carriage for movably holding a laser head (not shown), which is arranged so as to be movable in the radial direction of the compact optical disk 2.

The lever 40, the slide support 61, the spring 70, the disk supporting base 72 having the supporting portions 77, 78, 79 and the like described above move the compact optical disk 2 stored in the tray 3 in association with the rotation of the cam 18 to the table 87. A disk elevating means for descending in the direction and elevating from the table 87 is configured.

In addition, FIGS. 1, 3, and 9 (a), (b),
Reference numeral 91 shown in (c) is a wheel that is disposed above the table 87 so as to face it and can abut against the compact optical disc 2. Reference numeral 92 is an arm that holds the wheel 91 at its tip. The end portion is rotatably supported by a bracket 93 fixed to the chassis 1 via a shaft 94. 95
Is a lever, and one end of which is attached to the rising portion 96 formed on the arm 92.
It is rotatably supported via 97 and the above-mentioned cam 18 is attached to the other end.
Has a roller 98 that engages with the second cam portion 20, and has a bent portion 99 that can come into contact with the surface of the arm 92 on one side. 100 is a first spring, the upper end of which is attached to the lever 95,
The lower end is attached to a hanging portion 101 formed at the end of the arm 92, and urges the lever 95 and the arm 92 to engage with each other. A second spring 102 has one end engaged with the end of the lever 95 on the roller 98 side and the other end engaged with the rising portion 57 of the bracket 54 described above, and the roller 98 of the lever 95 is engaged with the second cam. Department
It is biased to engage 20. Table 8 above
7. The compact optical disk 2 housed in the tray 3 can be rotated by the rotation of the cam 18 by means of the wheel 91, the arm 92, the lever 95, the first spring 100, the second spring 102 and the like. A disk gripping / releasing means for gripping and releasing the grip is configured.

Reference numeral 103 shown in FIG. 1 and FIG. 3 is a switch that can be turned on and off by the stopper 7.
When it becomes FF, the motor 17 is driven.

The operation of the embodiment thus configured is as follows.

(1) [Before Storage of Compact Optical Disk 2 in Tray 3] As shown in FIG. 1, the tray 3 is arranged outside the chassis 1, and the stopper 7 attached to the slide rail 6 is installed.
Contacts the switch 103, which causes the switch 103 to
Is ON, for example. The cams 18 are in the positional relationship shown in FIG.

At this time, the roller 43 of the tober 39 is the small diameter portion of the first cam portion 19.
24, while the slide rail 5 is in a position away from the lever 39, so that the tray 3 is in the unlocked state and is free to move in the direction of the chassis 1.

Further, the roller 47 of the lever 40 engages with the stopper portion 25 of the first cam portion 19, that is, engages with the small diameter portion 24 of the first cam portion 19, while the slide support 61 moves away from the lever 40. Therefore, as shown in FIG. 5, the shafts 68 and 69 fixedly mounted on the slide rail 5 are located at the left ends of the elongated holes 66 and 67 of the slide support 61 in the figure, and the base plate of the disk support 72. The shafts 80, 81 fixed to the rising portions 74, 75 of the 73 are located at the upper ends of the slanted holes 64, 65 of the slide support 61, whereby the disk supporting base 72 is supported in the upper position, and the supporting portions thereof are supported. 7
7,78,79 are in a state of protruding from the holes 4a, 4b, 4c of the circular recess 4 of the tray 3.

Further, as shown in FIG. 8 (a), the roller 98 is engaged with the lower portion 26 of the second cam portion 20, and accordingly, as shown in FIG. 9 (a), the first The force of the spring 100 keeps the lower end of the bent portion 99 of the lever 95 in contact with and in contact with the surface of the arm 92, and the arm 92 is at a height position sufficiently separated from the table 87. The wheel 91 held by 92 is also at a height away from the table 87.

Further, as shown in FIG. 8 (a), the roller of the lever 41 is
48 fits into the large-diameter portion 23 of the second cam portion 19, so that the overhanging portion 51 of the lever 41 is located away from the switches 49, 50, whereby these switches 49, 50 are For example, OFF
It is in a state.

Further, as shown in FIG. 8 (a), the lever 58 is in a position in contact with the switch 52 via the connecting rod 60 connected to the lever 39, whereby the switch 52 is turned on, for example. There is.

Further, as shown in FIG. 8 (a), the switch 7 is not in contact with the switch 53.
Is in the OFF state, for example.

(2) [Housing of the compact optical disc 2 in the tray 3 and positioning of the compact optical disc 2 in the chassis 1] In the state of (1) above, the circular recess 4 of the tray 3 is formed.
When the compact optical disk 2 is housed on the supporting portions 77, 78, 79 projecting inward, and the tray 3 is slightly pushed in the direction of the chassis 1, the stopper 7 is separated from the switch 103, whereby the switch 103 is released. Is turned off, a drive signal is output from the switch 103 to the motor 17 shown in FIG. 2 through a control device (not shown), the gear 12 rotates, and the gear 1
The gear 9 rotates via 1,10, whereby the rack 8, that is, the slide rail 5 moves in the direction of the chassis 1, and the tray 3 in which the compact optical disk 2 is housed integrally with the slide rail 5 is the chassis 1. Move in the direction.

Then, as shown in FIG. 8B, when the stopper 7 comes into contact with the stopper 54a attached to the bracket 54, the movement of the stopper 7, that is, the movement of the slide rail 5 is stopped, and the tray 3 or the compact optical disk 2 is stopped. Is positioned at a predetermined position in the chassis 1, and the hole formed in the center of the compact optical disc 2 faces the spindle 88. At this time, as shown in FIG. 8 (b),
The stopper 7 comes into contact with the switch 53, whereby the switch 53 is turned on, and a drive stop signal and a drive signal are output to the motor 17 and the motor 38 via a controller (not shown), respectively, and the motor 17 is driven. Stops and the drive of the motor 38 starts.

(3) [Locking of the tray 3 with rotation of the cam 18, lowering of the compact optical disc 2 to the table 87, and start of gripping the compact optical disc 2] FIG. Gear 3 shown
The gears 21, that is, the cam 18 rotates in the clockwise direction in FIG. 8 (b). When the cam 18 is rotated to the state shown in FIG. 8 (c), the roller 43 of the lever 39 is rotated.
Engages the large diameter portion 23 of the first cam portion 19, that is, the lever
39 rotates clockwise, which causes the slide rail 5
The protrusion 45 of the lever 39 enters into the notch 44 formed in the ridge, and the protrusion 45 engages with the edge of the notch 44 so that the slide rail 5, that is, the tray 3 is immovably locked. The compact optical disc 2 stored in the tray 3 is held so as not to move in the horizontal direction.

At this time, as shown in FIG. 8 (c), the lever 40
The roller 47 of the first cam portion 19 is also engaged with the large diameter portion 23 of the first cam portion 19, and the snawachi lever 40 is rotated counterclockwise, whereby the lever 40 is engaged with the overhang portion 62 of the slide support 61. , Spring
The slide support 61 is pushed toward the tray 3 against the force of 70, and as a result, as shown in FIG. 6, the shafts 68, 69 fixedly mounted on the slide rail 5 are formed in the elongated holes 66, 66 of the slide support 61.
The link 82, 83 (shown in FIG. 2) is located at the right end of the figure 67 at the same time, and the link support 82, 83 (shown in FIG. 2) is rotated at the same time.
Shafts 80 and 81 fixed to 75 are the slant holes 6 of the slide support 61.
It is located at the lower end of 4,65, whereby the disk supporting base 72, that is, the supporting portions 77, 78, 79 is lowered, and the central hole of the compact optical disk 2 is engaged with the taper of the peripheral edge of the spindle 88.
Guided by this taper, centering of the rotary system of the compact optical disc 2 is performed.

At this time, as shown in FIG. 8 (c), the lever 39
The connecting rod 60 moves with the rotation of the lever.
58 rotates counterclockwise, the contact between the lever 58 and the switch 52 is released, the switch 52 is turned off, and, for example, a grip (clamp) start signal is output to a control device (not shown).

Then, as shown in FIG. 8 (c), the roller 98 is in the second position.
The lever 95 and the arm 92 rotate counterclockwise about the shaft 94 as a fulcrum as shown in FIG. 9 (b) as the cam portion 20 gradually engages with the high portion 27 of the cam portion 20. As a result, the wheel 91 presses the compact optical disc 2, the compact optical disc 2 is placed on the table 87, and the spindle 88 sinks into the table 87.
The compact optical disc 2 is held between the 91 and the table 87.

(4) [End of gripping of compact optical disc 2] When the cam 18 further rotates clockwise from the state of (3) above, the roller 48 of the lever 41 causes the first cam to move as shown in Fig. 8 (d). The recessed portion 25a of the portion 19 is engaged, whereby the overhanging portion 51 of the lever 41 comes into contact with the switches 49, 50, these switches 49, 50 are turned on, and the control devices (not shown) from these switches 49, 50 are turned on. For example, a gripping (clamping) end signal and a drive signal for the carriage 90 are output.

Further, as shown in FIG. 8 (d), as the roller 98 engages with the high portion 27 of the second cam portion 20 of the cam 18, as shown in FIG. 9 (c), the spring 100 The lever 95 slightly rotates counterclockwise in the drawing against the force of the shaft 97 as a fulcrum, and the overstroke of the assembly including the arm 92 and the lever 95 is absorbed.

Then, after the carriage 90 is moved in the radial direction of the compact optical disc 2, the recording of the compact optical disc 2 is read by the laser head (not shown) or the recording of the compact optical disc 2 is performed.

When the compact optical disc 2 is taken out from the tray 3, the cam 18 is rotated in the opposite direction to release the grip of the compact optical disc 2 from the table 87 of the compact optical disc 2. Ascending and unlocking of the tray 3 are performed, and then the tray 3 moves in the direction away from the chassis 1 contrary to the above.

In the embodiment configured as described above, a cam 18 that rotates in conjunction with the positioning operation of the tray 3 in the chassis 1 is provided, and a lever 39 that operates in conjunction with the cam 18 is provided.
Etc., a trail lock / release means, a lever 40, a slide support 61, a disk supporting means 72, a disk lifting means, a lever 95, an arm 92, a wheel 91, a table.
Since the disc gripping / releasing means composed of 87 etc. is provided, it is possible to favorably realize the reading of the record of the compact optical disc 2 and the writing of the record to the compact optical disc 2 simply by using one cam. Therefore, the number of members can be suppressed, and the structure is simplified. Further, since the number of members can be suppressed and the structure is simple, the member arrangement space can be small.

In addition, it is possible to read the record of the compact optical disc 2 and to write the record to the compact optical disc 2, in particular, through one slide support 61. Therefore, from this also, the number of members can be suppressed, The structure is simple and the space for arranging the members is small.

Further, the disc gripping / releasing means includes a tehble 87 on which the compact optical disc 2 can be placed, a wheel 91 arranged to face the table 87 and abuttable on the compact optical disc 2, and the wheel 91. An arm 92 that is held and rotatable, a lever 95 that is rotatably provided in a direction in which the arm 92 is engaged with and away from the arm 92, and a lever 95 that rotates in conjunction with rotation of the cam 18, and this lever. A first spring 100 biases the lever 95 and the arm 92 such that the arm 95 engages with the arm 92, and a second spring 100 biases the lever 95 such that the lever 95 engages the cam 18. Since the spring 102 is provided, after the compact optical disc 2 is gripped with a predetermined gripping force, the arm 92 is rotated by the rotation of the lever 95 against the force of the first spring 100. Good overstroke of assembly consisting of lever 95 Absorbed in that, the can to hold the gripping force of the connexion compact optical discs 2 to be constant.

In addition, a switch 53 that outputs a stop signal for driving the motor 17 that moves the tray 3 and a drive signal for the motor 38 that drives the cam 18, a switch 52 that outputs a grip start signal for the compact optical disk 2 by the arm 92, a compact optical switch. Switch 49, a carriage that outputs a gripping end signal of the disk 2
One switch 50 that outputs 90 drive signals
The switch mounting space can be minimized because it is held by 54 and is arranged at the edge of the chassis 1 near the cam 18.

[Effect of device]

As described above, according to the present invention, after the optical disc is gripped with a predetermined gripping force, the assembly of the arm and the lever is formed by the rotation of the lever against the force of the first spring. The overstroke of (1) is satisfactorily absorbed, so that the gripping force of the optical disk can be kept constant and the manufacturing accuracy of the cam, lever, arm, etc. can be eased.

Further, it is possible to satisfactorily realize the recording of the optical disc and the writing of the recording to the optical disc through only one cam, and therefore, the number of members can be suppressed as compared with the conventional one, and the structure is simplified. Therefore, the manufacturing cost can be reduced. Further, since the number of members is reduced and the structure is simple, the space for arranging the members can be small, and therefore the overall external dimensions can be suppressed to the minimum and the device can be made compact.

[Brief description of drawings]

1 to 9 (a), (b) and (c) are explanatory views showing an embodiment of the optical disk drive device of the present invention, and FIG. 1 is a plan view showing a state before the optical disk is mounted. FIG. 2 is a rear view showing a state before mounting the optical disc, FIG. 3 is a plan view showing a state of positioning the tray in the main body, and FIG. 4 (a) is a plan view of a cam provided in this embodiment. Fig. 4 (b) is a longitudinal sectional view of the cam shown in Fig. 4 (a), Fig. 4 (c) is a characteristic diagram of the second cam portion of the cam shown in Fig. 4 (a), 5 to 7 are explanatory views showing the disc elevating means provided in this embodiment, FIG. 5 is a side view showing a state before the optical disc is mounted, corresponding to FIG. 1, and FIG. 6 is FIG. Fig. 7 is a side view showing a state of positioning the tray corresponding to Fig. 7 in the main body, Fig. 7 is an exploded view, and Figs. 8 (a), (b), (c), and (d) are provided in this embodiment. Explanatory view showing a series of operations accompanying the rotation of the cam, FIG. 9 (a), is an explanatory diagram showing the operation of (b), (c) the disk gripping and releasing means provided in this embodiment. 1 ... Cherashi, 2 ... Compact optical disk, 3 ...
Tray, 4 ... Circular recess, 7 ... Stopper, 18 ... Cam, 19 ... First cam part, 20 ... Second cam part, 21 ...
Gear part, 23 …… Large diameter part, 24 …… Small diameter part, 25 …… Stopper part, 26 …… Lower part, 27 …… High part, 39,40,41,58,95 …… Lever, 43,47 , 48,49 …… Roller, 49,50,52,53,103 …… Switch, 55,56,70 …… Spring, 60 …… Coupling rod, 61 …… Slide support, 64,64 …… Inclined hole, 66, 67 …… elongated hole, 72 ……
Disk support, 73 …… substrate, 74, 75, 76 …… rising part,
77,78,79 …… Supporting part, 82,83 …… Connecting link, 87 …… Table, 88 …… Spindle, 91 …… Wheel, 92 …… Arm, 99 …… Bending part, 100 …… First Spring, 102 ... second spring.

Claims (1)

[Scope of utility model registration request] 1. A tray in which an optical disc is housed and which can be moved toward and away from the main body, a cam which interlocks with a positioning operation of the tray in the main body, and a tray which interlocks with the cam. The optical disk housed in the optical disk is rotatably gripped, and the disk gripping / releasing means is provided for releasing the gripping. The disk gripping / releasing means is a table on which the optical disk can be placed, and a table facing the table. And a wheel capable of contacting the optical disc, and an arm that holds the wheel and is rotatable in a direction toward and away from the optical disc housed in the tray, and an arm that engages with the arm. A lever that is rotatably provided in a mating direction and a distant direction and that rotates in conjunction with the cam, and a lever that engages with the lever and the arm. It is composed of a first spring for urging the bar and the arm and a second spring for urging the lever so that the lever engages with the cam. When the gripping operation is carried out, the lever and the arm are rotated against the spring force of the spring, and further, after gripping the disk, only the lever comes into contact with the arm. On the other hand, the optical disk drive device is characterized in that the optical disk drive device is rotated against the first spring.