CN206103320U

CN206103320U - Marble robot toy

Info

Publication number: CN206103320U
Application number: CN201620907778.5U
Authority: CN
Inventors: 邱雨夫
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-08-18
Filing date: 2016-08-18
Publication date: 2017-04-19
Anticipated expiration: 2026-08-18

Abstract

The utility model discloses a marble robot toy, including body, power and first arm, still including establishing the actuating mechanism in the arm, intact full -tooth wheel, establishing at the first slider of firsthand bizhong the slidable, taking turns a rack and a fixture who meshes with intact full -tooth. Marble robot toy still includes the trigger mechanism, establishes switch and control system in trigger mechanism one side to supply an actuating mechanism to drive trigger mechanism and then trigger switch. Implement the technical scheme of the utility model, marble robot toy realizes the power transmission between an actuating mechanism and the slider through not intact full -tooth wheel and rack, and then realizes jetting out of marble to an actuating mechanism cannot not drive intactly the full -tooth wheel simultaneously and rotates and trigger mechanism motion, and degree of automation is higher, and is more convenient when making the user the object for appreciation, in addition, the hand that the people had been simulated to form that this marble robot toy jetted out the marble through the arm jets out the marble action, has the interest more.

Description

Hoodle robot toy

Technical field

This utility model is related to toy art, more particularly, to a kind of hoodle robot toy.

Background technology

At present the existing robot toy that can launch hoodle manually launches mostly, and automaticity is not Height, it is cumbersome when playing；It is interesting relatively low and it is single to launch the mode of hoodle.

Utility model content

The technical problems to be solved in the utility model is, for drawbacks described above of the prior art, there is provided one kind can be with Launch the hoodle robot toy of hoodle automatically in arm.

This utility model solves the technical scheme that its technical problem adopted：A kind of hoodle robot toy is constructed, is wrapped The first arm for including body, power supply and being connected with body, it is characterised in that also including the first driving machine being located in arm Structure, the partial gear for rotating, the first slide block being slidably disposed in the first arm are driven by the first drive mechanism, the is located at On one slide block and the tooth bar that can engage with partial gear and it is located on the first arm and hoodle can be clipped in first The first clamping device in jaws, tooth bar parallel to the first slide block glide direction, with by partial gear band movable slider stretch Go out to from the first jaws of the first clamping device.

Hoodle robot toy also includes the trigger mechanism driven by the first drive mechanism, is located at opening for trigger mechanism side The control system closed and electrically connect with the first drive mechanism and switch, so that the first drive mechanism drives trigger mechanism and then touches Switch is sent out, so that control system stops the first drive mechanism when switch is triggered.

Preferably, trigger mechanism includes the cam driven by the first drive mechanism, for cam rotation and trigger switch, with Stop the first drive mechanism when switch is triggered for control system.

Preferably, partial gear and cam synchronous axial system.

Preferably, switch as cut-off switch, so that control system stops the first drive mechanism when switch is triggered.

Preferably, slide block is including base portion and is located on base portion and propels bar parallel to slide block glide direction, to pass through Partial gear makes to propel bar and stretches out from the first jaws of the first clamping device with movable slider.

Preferably, the first clamping device includes at least two first holders, and at least two first holders define the First jaws of one clamping device；First holder can turn to be connected with the first arm；First clamping device includes and at least two The STATEMENT OF FEDERALLY SPONSORED of the first holder linkage, STATEMENT OF FEDERALLY SPONSORED is slidably disposed in the first arm, so that the first holder can be synchronously Swing around pivot center.

Preferably, the first clamping device includes the pivot center of the rotating disk and rotating disk being located at can turning on the first arm Between at least two first holders, rotating disk to be provided with and stretch out hole for what slide block stretched out, so that slide block is reached from hole is stretched out In first jaws of the first clamping device.

Preferably, hoodle robot toy includes being located in body and can driving the first the 3rd driving rolled over Mechanism.

Preferably, hoodle robot toy include the second arm being connected with body, be located on the second arm second Clamping device；Second clamping device includes the second drive mechanism, is slidably disposed in the second arm and by the second drive mechanism The second slide block and the second arm for driving can turn the second holder for connecting, and the second holder defines the second clamping device Second jaws, the second slide block and the second holder link, to drive the second slide block and then drive second by the second drive mechanism Holder swings around pivot center.

Preferably, hoodle robot toy includes being located in body and can driving the second the 4th driving rolled over Mechanism.

Implement the technical solution of the utility model, at least with following beneficial effect：Hoodle robot toy is not by Completely gear and tooth bar are transmitted realizing the power between the first drive mechanism and slide block, and then realize the injection of hoodle, and First drive mechanism drives partial gear to rotate and trigger mechanism motion simultaneously, and once switch means that band for triggering Move a slide block and project a hoodle, then motor just stopped, to treat next injection, it is not necessary to which user is projected manually Hoodle, automaticity is higher so that convenient when user is played；Additionally, hoodle robot toy is penetrated by arm Go out the form simulation hand motion of people of hoodle, more with interest.

Description of the drawings

Below in conjunction with drawings and Examples, the utility model is described in further detail, in accompanying drawing：

Fig. 1-4 is axonometric drawing of the hoodle robot toy in the preferred embodiment of this utility model one in different visual angles.

Fig. 5 is the front view of the hoodle robot toy in Fig. 1.

Fig. 6,7 be hoodle robot toy in Fig. 1 explosive view.

Fig. 8,9 are that the first arm, the first clamping device and the 3rd drive mechanism of hoodle robot toy in Fig. 1 is shown It is intended to (the first slide block is not extended out in the first jaws).

Figure 10 is showing for the first arm, the first clamping device and the 3rd drive mechanism of the hoodle robot toy in Fig. 1 It is intended to (the first slide block is reached in the first jaws).

Figure 11-13 is the explosive view of the first arm, the first clamping device and the 3rd drive mechanism in Fig. 8.

Figure 14-16 is the first arm in Fig. 8, the first clamping device and the 3rd drive mechanism under another explosive state Explosive view.

Figure 17,18 be hoodle robot toy in Fig. 1 the second arm, the second clamping device and the 4th drive mechanism Explosive view.

Figure 19-21 is the axonometric drawing of first slide block of the hoodle robot toy in Fig. 1.

Figure 22,23 be respectively hoodle robot toy in Fig. 1 the second slide block axonometric drawing and front view.

Figure 24,25 are respectively the signal of the first arm in Fig. 1 under clamping hoodle state and in the case where hoodle state is projected Figure.

Wherein, 100. body, 1. the first arm, 11. first slide blocks, 111. base portions, 112. propel bar, 12. tooth bars, and 13. First drive mechanism, 14. partial gears, 15. trigger mechanisms, 151. cams, 16. switches, 17. first clamping devices, 171. First holder, 172. STATEMENT OF FEDERALLY SPONSOREDs, 173. rotating disks, 17b. stretches out hole, the jaws of 17a. first, 2. the second arm, 21. second clampings Mechanism, 211. second holders, 212. second slide blocks, 213. back-moving springs, the jaws of 21a. second, 22. second drive mechanisms, 51. wheels, 5. pin components, 52. hoofing part mechanisms, 3. the 3rd drive mechanism, 4. the 4th drive mechanism.

Specific embodiment

In order to be more clearly understood to technical characteristic of the present utility model, purpose and effect, accompanying drawing is now compareed detailed Illustrate specific embodiment of the present utility model.

【Embodiment one】

As shown in Fig. 1-2 3, a kind of hoodle robot toy, including body 100, power supply and body are present embodiments provided First arm 1 of 100 connections, also drives rotation including the first drive mechanism 13 being located in arm, by the first drive mechanism 13 Partial gear 14, be slidably disposed in the first arm 1 the first slide block 11, be located on the first slide block 11 and can be with The tooth bar 12 of the engagement of partial gear 14, the first folder for being located on the first arm 1 and hoodle being clipped in the first jaws 17a Hold mechanism 17, tooth bar 12 parallel to the first slide block 11 glide direction, with by partial gear 14 with movable slider reach from In first jaws 17a of the first clamping device 17.

Hoodle robot toy also includes the trigger mechanism 15 driven by the first drive mechanism 13, is located at trigger mechanism 15 1 The switch 16 of side and the control system electrically connected with the first drive mechanism 13 and switch 16, so that the first drive mechanism 13 drives Trigger mechanism 15 and then trigger switch 16, so that control system stops the first drive mechanism 13 when switch 16 is triggered.Power supply For needing the mechanism of driven by power to power to the various of hoodle robot toy；First drive mechanism 13 is used for project bullet Pearl and trigger switch 16 provide power；First clamping device 17 is used to clamp hoodle；First slide block 11 is used to that first will to be clamped in Hoodle in the jaws of clamping device 17 is projected；Partial gear 14 and tooth bar 12 are used to pass the power of the first drive mechanism 13 Slide block is delivered to, to realize the slip-stick of slide block.

Partial gear 14 refers to that the gear teeth are not covered with the gear of whole circumference, and the drive mechanism being made up of this gear is referred to as The mechanism of partial gear 14.In the present embodiment, partial gear 14 does intermittent movement by its toothed portion band movable slider.

Wherein, the first drive mechanism 13 can be the mechanism of all offer power such as motor.

Specifically, when hoodle robot toy is played, hoodle is clamped in into the first folder of the first clamping device 17 In mouth 17a；First drive mechanism 13 drives partial gear 14 to rotate and drive trigger mechanism 15 to move, partial gear 14 Toothed portion engage with tooth bar 12, partial gear 14 drive the first slide block 11 slide, the first slide block 11 is to the first jaws 17a In stretch out, then hoodle is propelled away, so as to realize project hoodle function；Hereafter the toothed portion of partial gear 14 with Tooth bar 12 departs from, and the trigger switch 16 of trigger mechanism 15 so that the first drive mechanism 13 stops, and partial gear 14 and One slide block 11 no longer links, i.e., the first slide block 11 is unfettered, can now promote the first slide block 11 to contract from the first jaws 17a Go back, be to make the first slide block 11 reset, and again hoodle is clipped in the jaws of the first clamping device 17, to prepare to weigh next time It is new to start the first drive mechanism 13 to project hoodle again.In other words, the first drive mechanism 13 drives partial gear 14 simultaneously Rotate and trigger mechanism 15 is moved, once switch 16 means that and driven a slide block and projected a hoodle for triggering , then motor just stopped, to treat next injection.

Figure 24,25 are respectively that the first arm 1 holds hoodle and projects the schematic diagram of hoodle.

Wherein, trigger mechanism 15 can be the form of toggle, drive crank to enter by the first drive mechanism 13 And drivening rod carrys out trigger switch 16；Can also be the form of slider-crank mechanism, crank is driven by the first drive mechanism 13 And then band movable slider carrys out trigger switch 16；The form of cam 151 is can also be, by the first drive mechanism 13 with moving cam 151 Rotate to make the trigger switch 16 of cam 151.

In sum, the hoodle robot toy of the present embodiment realizes the first drive by partial gear 14 and tooth bar 12 Power transmission between motivation structure 13 and slide block, and then the injection of hoodle is realized, and the first drive mechanism 13 drives not simultaneously Completely gear 14 is rotated and trigger mechanism 15 is moved, and once switch 16 means that and driven a slide block and penetrated for triggering Go out a hoodle, then motor just stopped, to treat next injection, it is not necessary to which user projects manually hoodle, automaticity It is higher so that convenient when user is played；Additionally, hoodle robot toy projects the form simulation of hoodle by arm The hand of people projects hoodle action, more with interest.

【Embodiment two】

The hoodle robot toy of the present embodiment has done further improvement to the technical scheme of embodiment one, and it includes enforcement All the elements of the technical scheme of example one.

As shown in Fig. 1-5,8-16, the hoodle robot toy that the present embodiment is provided, including body 100, power supply and body First arm 1 of 100 connections, also drives rotation including the first drive mechanism 13 being located in arm, by the first drive mechanism 13 Partial gear 14, be slidably disposed in the first arm 1 the first slide block 11, be located on the first slide block 11 and can be with The tooth bar 12 of the engagement of partial gear 14, the first folder for being located on the first arm 1 and hoodle being clipped in the first jaws 17a Hold mechanism 17, tooth bar 12 parallel to the first slide block 11 glide direction, with by partial gear 14 with movable slider reach from In first jaws 17a of the first clamping device 17.

Trigger mechanism 15 can be the form of toggle, drive crank by the first drive mechanism 13 and then drive Connecting rod carrys out trigger switch 16；Can also be the form of slider-crank mechanism, crank and then band are driven by the first drive mechanism 13 Movable slider carrys out trigger switch 16；Can also be the form of cam 151, by the first drive mechanism 13 with moving cam 151 rotate come Make the trigger switch 16 of cam 151.In the present embodiment, trigger mechanism 15 is the form of cam 151.Specifically, the ball spring game machine Device people's toy includes the cam 151 driven by the first drive mechanism 13, the switch 16 for being located at the side of cam 151 and drives with first Motivation structure 13 and the control system of the electrical connection of switch 16, so that cam 151 is rotated and trigger switch 16, so that control system is being opened Pass 16 stops the first drive mechanism 13 when being triggered.When the projection of cam 151 is turned at switch 16 and by compressing switch 16 When, just trigger switch 16.

Preferably, partial gear 14 and the synchronous axial system of cam 151.Switch 16 is cut-off switch 16, for control system Stop being powered to the first drive mechanism 13 when switch 16 is triggered, to stop the first drive mechanism 13.

Slide block includes base portion 111 and is located on base portion 111 and propels bar 112 parallel to slide block glide direction, with logical Cross partial gear 14 and make to propel bar 112 with movable slider and stretch out from the first jaws 17a of the first clamping device 17, and then will folder Hoodle in the first clamping device 17 is projected.

First clamping device 17 includes at least two first holders 171, and at least two first holder 171 is defined First jaws 17a of the first clamping device 17, to clamp hoodle by least two first holder 171.First holder 171 can turn to be connected with the first arm 1；First clamping device 17 includes the linkage with the linkage of at least two first holder 171 Part 172, STATEMENT OF FEDERALLY SPONSORED 172 is slidably disposed in the first arm 1, so that the first holder 171 can synchronously around pivot center Swing；The linked manner of the first STATEMENT OF FEDERALLY SPONSORED 172 and at least two first holder 171 can be the first STATEMENT OF FEDERALLY SPONSORED 172 and be somebody's turn to do At least two first holders 171 are joined directly together, or the first STATEMENT OF FEDERALLY SPONSORED 172 is by connecting rod and at least two first folder Gripping member 171 is connected.Specifically, in the present embodiment, the quantity of the first holder 171 is three, is clamped with relatively stable Hoodle；Linkage recess is provided with per one first holder 171, STATEMENT OF FEDERALLY SPONSORED 172 is slidably enclosed within to be propelled on bar 112 and it Identical with the glide direction of the first slide block 11, STATEMENT OF FEDERALLY SPONSORED 172 is provided with linkage projection, and linkage projection is trapped in per one first holder In 171 linkage recess, can cause when STATEMENT OF FEDERALLY SPONSORED 172 is slided per the synchronous hunting of one first holder 171 so that the first clamping First jaws 17a of mechanism 17 is opened or is clamped.

Preferably, STATEMENT OF FEDERALLY SPONSORED 172 is located at the front of the base portion 111 of the first slide block 11, so that the first slide block 11 is when sliding Promote STATEMENT OF FEDERALLY SPONSORED 172 and then drive the first holder 171 to swing so that the first jaws 17a of the first clamping device 17 is opened.

First clamping device 17 is located at the front of the first slide block 11, and the first clamping device 17 includes being located at the first arm with can turning Between at least two first holders 171, rotating disk 173 is provided with confession to the pivot center of rotating disk 173 and rotating disk 173 on 1 What slide block stretched out stretches out hole 17b, so that the first slide block 11 is from the first jaws for stretching out hole 17b and reaching the first clamping device 17 In 17a, and the first holder 171 can be rotated around the first jaws 17a, so that hoodle robot toy has object for appreciation with a greater variety Method, brings higher interest.

First arm 1 is connected in which can turn with body 100, and hoodle robot toy includes being located in body 100 and can be with The 3rd drive mechanism 3 for driving the first arm 1 to rotate, so as to hoodle robot toy rotating or can swing up and down first Complete to launch hoodle this function while arm 1.

Hoodle robot toy includes that the second arm 2 being connected with body 100, second be located on the second arm 2 are pressed from both sides Hold mechanism 21；Second clamping device 21 includes the second drive mechanism 22, is slidably disposed in the second arm 2 and driven by second The second slide block 212 and the second arm 2 that mechanism 22 drives can turn the second holder for connecting, and the second holder defines second Second jaws 21a of clamping device 21, the second slide block 212 and the second holder link, to be driven by the second drive mechanism 22 Second slide block 212 further drives the second holder to swing around pivot center.Preferably, the second slide block 212 and the second holder structure Into sine mechanism, the linear motion of the second slide block 212 is converted to into the rotation of the second holder.

Second drive mechanism 22 includes the tapered shaft being slidably disposed on the second arm 2, and the second slide block 212 is provided with wedge Shape portion, tapered shaft is not parallel to each other with the glide direction of the second slide block 212, and for lozenges, the other end stretches out for one end of tapered shaft Outside second arm 2, so that user promotes tapered shaft；Tapered shaft is contacted with wedge-shaped part by lozenges, to be pushed away by tapered shaft Movable slider slides, and then drives the second holder around pivot axis and then make the second jaws 21a of the second clamping device 21 Open and/or clamp.Hoodle robot toy also includes the back-moving spring 213 being connected with the second slide block 212, back-moving spring 213 are used to provide restoring force to the second slide block 212, and then drive the second holder to rotate to clamp the second clamping device 21. So as to when user promotes tapered shaft, the second clamping device 21 opens；When user unclamps tapered shaft, the second clamping device 21 clamp.

Second arm 2 is connected in which can turn with body 100, and hoodle robot toy includes being located in body 100 and can be with The 4th drive mechanism 4 for driving the second arm 2 to rotate, so that hoodle robot toy can clip thing while rotating Or the second arm 2 is swung up and down, bring higher interest.

Wherein, the second drive mechanism 22, the 3rd drive mechanism 3 and the 3rd drive mechanism 3 can be motor etc. all carry For the mechanism of power.

Hoodle robot toy includes pin components 5, is located at the second drive mechanism 22 of the bottom of pin components 5, is located at leg In part 5 and the hoofing part mechanism 52 of the second drive mechanism 22 can be driven, so as to hoodle robot toy can be while walk It is dynamic, while the first arm 1 and the second arm 2 are rotated or swing up and down, while projecting hoodle and by second by the first arm 1 Arm 2 presss from both sides thing.

When hoodle robot toy is played, hoodle is clamped in the first jaws 17a of the first clamping device 17；The One drive mechanism 13 drives partial gear 14 to rotate and drive trigger mechanism 15 to move, the toothed portion of partial gear 14 Engage with tooth bar 12, partial gear 14 drives the first slide block 11 to slide, and the first slide block 11 stretches out in the first jaws 17a, so Hoodle is propelled away afterwards, so as to realize projecting the function of hoodle；Hereafter the toothed portion of partial gear 14 takes off with tooth bar 12 From, and the trigger switch 16 of trigger mechanism 15 so that the first drive mechanism 13 stops, and the slide block 11 of partial gear 14 and first No longer link, i.e., the first slide block 11 is unfettered, can now promote the first slide block 11 to shrink back from the first jaws 17a, i.e., It is to make the first slide block 11 reset, and again hoodle is clipped in the jaws of the first clamping device 17, to prepare to restart next time First drive mechanism 13 is projecting again hoodle.In other words, the first drive mechanism 13 drive partial gear 14 to rotate simultaneously with And trigger mechanism 15 is moved, once switch 16 means that and has driven a slide block and projected a hoodle for triggering, so Afterwards motor just stopped, to treat next injection.

In sum, the hoodle robot toy of the present embodiment realizes the first drive by partial gear 14 and tooth bar 12 Power transmission between motivation structure 13 and slide block, and then the injection of hoodle is realized, and the first drive mechanism 13 drives not simultaneously Completely gear 14 is rotated and trigger mechanism 15 is moved, and once switch 16 means that and driven a slide block and penetrated for triggering Go out a hoodle, then motor just stopped, to treat next injection, it is not necessary to which user projects manually hoodle, automaticity It is higher so that convenient when user is played；Additionally, hoodle robot toy projects the form simulation of hoodle by arm The hand of people projects hoodle action, more with interest.Further, hoodle robot toy also drives including second Mechanism 22, hoofing part mechanism 52 and the second arm 2 of thing can be pressed from both sides by the second clamping device 21, and the second arm 2 can clip thing while rotating or swinging up and down, and walk about such that it is able to one side, while rotating or swinging up and down first-hand The arm 2 of arm 1 and second, while hoodle is projected by the first arm 1 and thing is pressed from both sides by the second arm 2, with object for appreciation with a greater variety Method, brings higher interest.

Preferred embodiment of the present utility model is the foregoing is only, this utility model is not limited to, for this For the technical staff in field, this utility model can have various changes, combination and change.It is all it is of the present utility model spirit and Within principle, any modification, equivalent substitution and improvements made etc., should be included in right of the present utility model it It is interior.

Claims

1. a kind of hoodle robot toy, including body (100), power supply and the first arm being connected with the body (100) (1), it is characterised in that also including the first drive mechanism (13) being located in the arm, by first drive mechanism (13) Drive the partial gear (14) for rotating, the first slide block (11) being slidably disposed in first arm (1), be located at it is described On first slide block (11) and the tooth bar (12) that can engage with the partial gear (14) and it is located at first arm (1) on and the first clamping device (17) that can be clipped in hoodle in the first jaws (17a), the tooth bar (12) is parallel to described The glide direction of the first slide block (11), to drive the slide block to reach from the described first folder by the partial gear (14) In holding first jaws (17a) of mechanism (17)；

The hoodle robot toy also include the trigger mechanism (15) driven by first drive mechanism (13), be located at it is described The switch (16) of trigger mechanism (15) side and the control electrically connected with first drive mechanism (13) and the switch (16) System processed, so that first drive mechanism (13) drives the trigger mechanism (15) and then triggers the switch (16), for The control system stops first drive mechanism (13) when the switch (16) is triggered.

2. hoodle robot toy according to claim 1, it is characterised in that the trigger mechanism (15) is included by described The cam (151) that first drive mechanism (13) drives, so that the cam (151) rotates and triggers the switch (16), for The control system stops first drive mechanism (13) when the switch (16) is triggered.

3. hoodle robot toy according to claim 2, it is characterised in that the partial gear (14) is convex with described Wheel (151) synchronous axial system.

4. hoodle robot toy according to claim 2, it is characterised in that the switch (16) is cut-off switch (16), so that the control system stops first drive mechanism (13) when the switch (16) is triggered.

5. hoodle robot toy according to claim 1, it is characterised in that the slide block includes base portion and is located at institute State on base portion (111) and propel bar (112) parallel to the slide block glide direction, with by the partial gear (14) band Moving the slide block makes described to propel bar (112) and stretch out from first jaws (17a) of first clamping device (17).

6. hoodle robot toy according to claim 1, it is characterised in that first clamping device (17) include to Few two the first holders (171), described at least two first holders (171) define first clamping device (17) First jaws (17a)；First holder (171) can turn to be connected with first arm (1)；First clamping machine Structure (17) includes the STATEMENT OF FEDERALLY SPONSORED (172) with the linkage of described at least two first holders (171), and the STATEMENT OF FEDERALLY SPONSORED (172) can slide In being located at first arm (1) dynamicly, so that first holder (171) synchronously can swing around pivot center.

7. hoodle robot toy according to claim 6, it is characterised in that first clamping device (17) is including can It is located at the pivot center of rotating disk (173) on first arm (1) and the rotating disk (173) with turning described at least two Between individual first holder (171), the rotating disk (173) to be provided with and stretch out hole (17b) for what the slide block stretched out, for described Slide block is stretched out in first jaws (17a) that hole (17b) reaches first clamping device (17) from described.

8. the hoodle robot toy according to any one of claim 1-7, it is characterised in that including being located at the body (100) in and the 3rd drive mechanism (3) that first arm (1) rotates can be driven.

9. hoodle robot toy according to claim 1, it is characterised in that include what is be connected with the body (100) Second arm (2), the second clamping device (21) being located on second arm (2)；Second clamping device (21) includes Second drive mechanism, the second slide block for being slidably disposed in second arm (2) and being driven by second drive mechanism (212) and second arm (2) can turn the second holder (211) for connecting, second holder (211) defines institute Second jaws (21a) of the second clamping device (21) is stated, second slide block (212) is linked with second holder (211), To drive second slide block (212) by second drive mechanism and then drive second holder (211) around rotation Axis oscillating.

10. hoodle robot toy according to claim 9, it is characterised in that including being located in the body (100) simultaneously The 4th drive mechanism (4) that second arm (2) can be driven to rotate.