CN210890907U

CN210890907U - Projector hanging bracket

Info

Publication number: CN210890907U
Application number: CN201920988654.8U
Authority: CN
Inventors: 沈允骝
Original assignee: Hangzhou Navol Audio Visual Engineering Co ltd
Current assignee: Hangzhou Navol Audio Visual Engineering Co ltd
Priority date: 2019-06-28
Filing date: 2019-06-28
Publication date: 2020-06-30
Anticipated expiration: 2029-06-28

Abstract

The utility model relates to a projector hanger, which comprises a top fixed disk, a projector fixed mount and a main body tube, wherein the projector fixed mount is connected with an intermediate disk through a joint bearing, and the intermediate disk is connected with the main body tube; the joint bearings are at least three and are arranged symmetrically relative to the center of the middle disc, each joint bearing comprises an inner ring with an outer spherical surface and an outer ring with an inner spherical surface, the inner spherical surface of the outer ring and the outer spherical surface of the inner ring form a rolling friction pair, the outer ring is connected with an adjusting screw rod, an adjusting button is arranged on the middle disc, and the adjusting screw rod is in threaded fit with the adjusting button. The projector fixing frame is used for fixing the projector, the top fixing disc is used for connecting a ceiling, the main body pipe is used as a hanging main body, the middle disc and the joint bearing are connected with the main body pipe and the projector fixing frame, the joint bearing is provided with an outer ring and an inner ring matched with a spherical surface, therefore, the outer ring and the inner ring can be adjusted at multiple angles, the projector fixing frame can be adjusted at multiple angles relative to the middle disc, and the projection angle of the projector is adjusted.

Description

Projector hanging bracket

Technical Field

The utility model relates to a gallows especially relates to a projector gallows.

Background

A projector is an optical instrument that magnifies the contour of a workpiece using an optical element and projects it onto a screen. It can be used for profile measurement by transmitted light, and also can be used for measuring the surface shape of a blind hole and observing the surface of a part by reflected light. Under the background that the policies required by the state and the income of people are continuously improved, the implementation of rural culture sharing engineering further promotes the rapid growth of the market of the Chinese projector. At present, projectors are widely used in teaching, meeting, entertainment and home theater for showing, and projectors used in such places are generally fixed on the ceiling through a hanging bracket.

In order to stably, clearly and accurately project the video or image of the projector onto the curtain, the hanger for fixing the projector has the function of adjustment, including adjustment of the position and projection angle of the projector. There are three aspects to position adjustment: firstly, the height direction of the projector is adjusted; secondly, adjusting the distance of the projector relative to the curtain; and thirdly, adjusting the projector in the left-right direction relative to the curtain. The existing hanging bracket can only adjust the position, and cannot adjust the projection angle of the projector.

Disclosure of Invention

The utility model provides a projecting apparatus gallows for the fixed projecting apparatus of installation is provided with joint bearing on it, except can carrying out position control to the projecting apparatus, can also adjust the projection angle of projecting apparatus through joint bearing.

The utility model discloses a concrete technical scheme does: a projector hanging bracket comprises a top fixing disc, a projector fixing frame and a main body tube, wherein the projector fixing frame is connected with a middle disc through a joint bearing, and the middle disc is connected with the main body tube; the joint bearings are at least three and are arranged symmetrically relative to the center of the middle disc, each joint bearing comprises an inner ring with an outer spherical surface and an outer ring with an inner spherical surface, the inner spherical surface of the outer ring and the outer spherical surface of the inner ring form a rolling friction pair, the outer ring is connected with an adjusting screw rod, an adjusting button is arranged on the middle disc, and the adjusting screw rod is in threaded fit with the adjusting button.

The projector fixing frame is used for fixing a projector, the top fixing disc is used for connecting a ceiling, the main body pipe is used as a suspension main body, the middle disc and the joint bearing are connected with the main body pipe and the projector fixing frame, and the joint bearing is provided with an outer ring and an inner ring which are matched in a spherical surface mode, so that the outer ring and the inner ring can be adjusted in multiple angles, the projector fixing frame can be adjusted in multiple angles relative to the middle disc, and the projection angle of the projector is adjusted; the adjusting screw and the adjusting button form a thread transmission pair, and the position of the outer ring relative to the middle disc can be changed by rotating the adjusting button, so that the position of the projector fixing frame is lowered or raised, and the projection angle of the projector is changed; the number of the joint bearings is at least three, the support stability of the three joint bearings is better, and the balance is easier to achieve during adjustment.

Preferably, the inner ring is internally provided with the connecting assembly in a penetrating manner, the axis of the inner ring is kept parallel relative to the projector fixing frame, the axis of the adjusting screw rod is vertical to the axis of the outer ring, and the axis of the adjusting screw rod is kept parallel relative to the axis of the main body pipe.

Preferably, a swivel base is fixed on the projector fixing frame, a threaded hole is formed in the swivel base, the axis of the threaded hole is parallel to the projector fixing frame, and a counter bore is formed in the position, corresponding to the threaded hole, of the swivel base; the connecting assembly comprises a pin pipe and a pin, the pin pipe is inserted into the inner ring, the end part of the pin pipe is inserted into the counter bore, and the pin penetrates out of the pin pipe and is screwed into the threaded hole of the rotary seat.

Preferably, the middle plate is provided with an adjusting knob rotating hole, the adjusting knob is provided with a knob portion and a cylinder, the cylinder is inserted into the rotating hole, the lower end of the rotating hole is provided with a lower counter bore, a bearing is embedded into the lower counter bore, the end portion of the cylinder is provided with a clamping groove, a clamping spring is clamped into the clamping groove, and the clamping spring limits the bearing. The main part is inserted and is rotated downtheholely, rotates the adjusting knob, and the adjusting knob can not produce axial displacement, and adjusting screw and adjusting knob have formed the lead screw structure.

Preferably, a threaded hole is formed in the axis of the adjusting knob, an external thread is formed in the outer surface of the adjusting screw, the adjusting screw is screwed into the threaded hole of the adjusting knob, and the position of the inner ring relative to the middle disc can be adjusted by rotating the adjusting knob.

Preferably, the middle of the middle disc is provided with a main pipe mounting hole and an opening, so that the main pipe mounting hole is communicated with the outside of the middle disc, the main pipe mounting hole is circular, the middle disc is provided with a radial screw hole corresponding to the main pipe mounting hole, and a main pipe rotating lock pin penetrates into the radial screw hole to lock the main pipe. The main body pipe is arranged in the main body pipe mounting hole, so that the main body pipe can rotate around the axis, the horizontal deflection adjustment of the projection angle is realized, and the main body pipe rotates and is locked by the locking nail after the adjustment.

Preferably, the main pipe mounting hole is circular, the width of the opening is smaller than the diameter of the main pipe mounting hole, the axial length of the main pipe mounting hole is smaller than the thickness of the intermediate disc, the intermediate disc is provided with a step which is inward convex in the radial direction on the upper portion of the main pipe mounting hole, the step surrounds a semicircular hole, and the diameter of the semicircular hole is equal to the width of the opening.

Preferably, the main body pipe is of a telescopic structure and comprises a main body outer pipe and a main body inner pipe which are sleeved with each other, the top fixing disc is fixed to the end portion of the main body outer pipe, the bottom of the main body inner pipe is fixedly provided with a rotary disc, a ring groove is formed in the periphery of the rotary disc, and the rotary disc is matched with the middle disc.

Preferably, the main part inner tube and the main part outer tube are aluminum alloy tubes, the pipe wall of the main part inner tube is provided with an inward convex axial rib and a connecting circular rib, an axial groove is formed in the axial rib, a long strip opening is formed in the outer surface of the main part inner tube, the long strip opening is communicated with the axial groove, an axial hole is formed in the axial rib, a connecting hole is formed in the connecting circular rib, a connecting square rib protruding in the phase is arranged on the pipe wall of the main part outer tube, a connecting hole is formed in the connecting square rib, the appearance of the connecting square rib is matched with the shape of the axial groove, the connecting square rib is inserted into the axial groove to form a guide structure, relative to the main part inner tube, of the main part outer tube, the radial round hole corresponds to the axial hole, the main part outer tube and the main part inner tube are.

Preferably, the projector fixing frame comprises a fixing frame body and a plurality of connecting arms connected with the fixing frame body, the fixing frame body is in a circular ring shape, a plurality of sections of arc-shaped grooves are formed in the circular ring, and one ends of the connecting arms are connected to the arc-shaped grooves; the connecting arm is of a telescopic structure and comprises a connecting inner arm and a connecting outer arm which are mutually inserted, and the connecting outer arm and the connecting inner arm are fixed through locking screws after being inserted. Due to the arrangement of the arc-shaped groove, the adjusting range of the connecting arm is larger, especially the area of a fixing hole on the projector is smaller, and when the connecting arm retracts and is easy to interfere, the interference of the connecting arm can be avoided through the position adjustment of the arc-shaped groove.

The utility model has the advantages that: the projector fixing frame is used for fixing the projector, the top fixing disc is used for connecting a ceiling, the main body pipe is used as a hanging main body, the middle disc and the joint bearing are connected with the main body pipe and the projector fixing frame, the joint bearing is provided with an outer ring and an inner ring matched with a spherical surface, therefore, the outer ring and the inner ring can be adjusted at multiple angles, the projector fixing frame can be adjusted at multiple angles relative to the middle disc, and the projection angle of the projector is adjusted.

Drawings

FIG. 1 is a schematic structural view of the present invention;

fig. 2 is a top perspective view of the present invention;

fig. 3 is a bottom perspective view of the present invention;

FIG. 4 is a view A-A of FIG. 1 in accordance with the present invention;

fig. 5 is a sectional view of the joint bearing of the present invention;

fig. 6 is an exploded view of the present invention;

in the figure: 1. the top fixing disc comprises a top fixing disc, 2, a main body tube, 3, a main body outer tube, 4, a locking nail, 5, a main body inner tube, 6, an adjusting button, 7, an intermediate disc, 8, a fixing pin, 9, a clamping spring, 10, a clamping groove, 11, a pin tube, 12, an outer ring, 13, a rotary seat, 14, a fixing frame body, 15, a connecting outer arm, 16, a connecting inner arm, 17, a locking screw, 18, a pin, 19, an adjusting screw rod, 20, a main body tube rotating locking nail, 21, a connecting screw, 22, a central hole, 23, an axial hole, 24, an axial groove, 25, a rotary disc, 26, a bayonet, 27, a boss, 28, an arc-shaped groove, 29, an elongated groove, 30, an axial rib, 31, a connecting square rib, 32, a connecting round rib, 33, a connecting hole, 34, a slotted groove, 35, a gasket, 36, a cylinder, 37, a bearing, 38, an inner ring, 39, a flange, a ring groove.

Detailed Description

The invention will be further described with reference to specific embodiments and with reference to the accompanying drawings.

Example (b):

as shown in fig. 1 to 6, a projector hanger includes a top fixing plate 1, a projector fixing frame and a main tube 2, the projector fixing frame is connected to a middle plate 7 through a joint bearing, and the middle plate is connected to the main tube.

The top fixed disk is circular and has a central hole 22 in the middle. The top fixed disk is provided with a fixing hole on the disk surface, and the top fixed disk can be fixed on a ceiling through the fixing hole.

The main body tube 2 is of a telescopic structure (see fig. 2, 3 and 6), and comprises a main body outer tube 3 and a main body inner tube 5 which are sleeved with each other, and the main body outer tube and the main body inner tube are locked and fixed through radial locking nails 4 after being sleeved with each other. The main part inner tube and the main part outer tube are aluminum alloy tubes, the pipe wall of the main part inner tube is provided with inward convex axial ribs 30 and connecting circular ribs 32, the number of the axial ribs is three, the number of the connecting circular ribs is three, the interval between the three axial ribs is 120 degrees, the interval between the three connecting circular ribs is 120 degrees, and the axial ribs and the connecting circular ribs are staggered mutually. The cross section of the axial rib is square, the cross section of the connecting round rib is round, a square axial groove 24 is formed in the axial rib, a strip opening is formed in the outer surface of the inner pipe of the main body and communicated with the axial groove, and protruding retaining edges 39 are arranged on two side walls of an opening of the axial groove (see fig. 6 and fig. 4). The axial rib is provided with an axial hole 23, the axial hole is positioned at the bottom of the axial rib, the axial rib extends to the upper end from the lower end of the inner tube of the main body, and the length of the axial hole is smaller than that of the axial rib. The connecting round ribs are internally provided with connecting holes 33, the pipe wall of the main body outer pipe is provided with connecting square ribs 31 which are mutually raised, the connecting square ribs are internally provided with connecting holes 33, the periphery of the central hole of the top fixing disc is provided with connecting holes, and the connecting holes on the connecting square ribs correspond to the connecting holes on the top fixing disc and are fixed through connecting screws 21. The shape of the connecting square rib is matched with the shape of the axial groove, the position of the connecting square rib corresponds to the position of the axial groove of the main body inner pipe, the connecting square rib is inserted into the axial groove to form a guide structure for the main body outer pipe to stretch relative to the main body inner pipe, the two sides of the connecting square rib are provided with concave square grooves, and the square grooves are matched with the flanges. Be provided with radial round hole on the main part outer tube, radial round hole corresponds the axial hole, and the lock pin inserts and pierces through the axial hole from the radial round hole of main part outer tube and stretches into the main part inner tube, the end screw in latch segment that stretches out of lock pin. After the telescopic length of the main body outer pipe and the main body inner pipe is adjusted, the locking nail and the locking block are screwed to fix the main body outer pipe and the main body inner pipe. The bottom of the inner pipe of the main body is fixed with a rotary disk 25, the periphery of the rotary disk is provided with a ring groove 40, the central position of the rotary disk is provided with a central hole, and the central hole of the rotary disk is communicated with the central hole of the top fixed disk (see figure 6). Three connecting holes are formed in the rotary disc, the positions of the connecting holes correspond to the connecting circular ribs of the inner tube of the main body, and the connecting screws penetrate through the connecting holes and are screwed into the connecting circular ribs. The connecting square rib of the main body outer pipe and the connecting round rib of the main body inner pipe are both provided with a slot 34, and the length of the slot is equal to that of the connecting square rib and the connecting round rib at the position of the slot.

The middle plate is triangular, and three adjusting button rotating holes 42 are arranged on the middle plate and symmetrically arranged in a triangular shape. The centre of intervalve is provided with main part pipe mounting hole and sets up opening 26 and makes main part pipe mounting hole intercommunication intervalve outside, and the main part pipe mounting hole is circular, and the aperture of main part pipe mounting hole is the same with the external diameter of carousel, and the axial height of main part pipe mounting hole is the same with the thickness of carousel, and the position that the intervalve corresponds the main part pipe mounting hole is provided with radial screw, and the main part pipe that screws into in radial screw rotates locking nail 20, and in the main part pipe mounting hole was gone into to the carousel card, the tip that the main part pipe rotated the locking nail pushed up into the annular of carousel always. The number of the radial screw holes is three, one of the radial screw holes is positioned at the position of the rotating hole, so that the fastening screw is directly screwed into the radial screw hole, and the other two metallographic screw holes are screwed into the main pipe rotating locking screw. The width of the opening is smaller than the aperture of the main pipe mounting hole, the axial length of the main pipe mounting hole is smaller than the thickness of the middle disc, the middle disc is provided with a step 41 (see fig. 6) protruding inwards in the radial direction on the upper portion of the main pipe mounting hole, a semicircular hole is defined by the step, the aperture of the semicircular hole is equal to the width of the opening, and a U-shaped structure is formed.

Three joint bearing is connected to the position in the three rotation hole of intervalve, be provided with adjusting knob 6 in the rotation hole, the adjusting knob has button portion and cylinder 36, the cylinder inserts in the rotation hole, the upper end in rotation hole is provided with the counter bore, the lower extreme sets up down the counter bore, it has packing ring 35 to go up the embedded packing ring 35 of counter bore, embedding bearing 37 in the counter bore, the external diameter of button portion is greater than the external diameter of cylinder, be provided with anti-skidding line on the outer cylinder of button portion, the tip of cylinder sets up draw-in groove 10, draw-in spring 9 is blocked in the draw-in groove, the jump ring is spacing to the bearing. The joint bearing comprises an inner ring 38 with an outer spherical surface and an outer ring 12 with an inner spherical surface, the inner spherical surface of the outer ring and the outer spherical surface of the inner ring form a rolling friction pair, the outer ring is connected with an adjusting screw rod 19, an inner screw hole is formed in the axis of an adjusting button, an external thread is arranged on the outer surface of the adjusting screw rod, and the adjusting screw rod is in threaded fit with the inner screw hole of the adjusting button to form a screw rod structure. The axis of adjusting screw parallels with the axis of main part pipe all the time, rotates the adjusting knob, can change adjusting screw's screw in size to change the position of the relative intermediate disc of outer lane. The middle disc is provided with radial screw holes corresponding to the positions of the rotating holes, the fixing pins 8 are screwed into the radial screw holes, and the adjusting buttons are screwed into the fixing pins and fixed after the rotation adjustment is finished.

The projector fixing frame comprises a fixing frame body 14 and a plurality of connecting arms connected with the fixing frame body, the fixing frame body is in a circular ring shape, three sections of arc-shaped grooves 28 are formed in the circular ring, the centers of the three sections of arc-shaped grooves are symmetrically arranged, and one ends of the connecting arms are connected to the arc-shaped grooves. The ring inside of fixed support body is provided with radial outstanding boss 27, is fixed with swivel mount 13 on the boss, and the boss is in the position between the arc wall, and swivel mount vertical fixation support body is provided with the screw hole on the swivel mount, and the axis of screw hole keeps parallel relative projector mount, and the position that corresponds the screw hole on the swivel mount is provided with the counter bore. The connecting arm is of a telescopic structure and comprises an inner connecting arm 16 and an outer connecting arm 15 which are mutually inserted, and the outer connecting arm and the inner connecting arm are fixed through a locking screw 17 after being inserted. The cross section of the connecting outer arm is C-shaped, the connecting inner arm is flat, a connecting counter bore is arranged at the end part of the connecting inner arm and used for being fixed with a projector, a threaded hole is formed in the other end of the connecting inner arm, and one end of the threaded hole of the connecting inner arm is inserted into the connecting outer arm. The outer connecting arm is provided with a long groove 29, a threaded hole of the inner connecting arm is opposite to the long groove, and a locking screw penetrates through the long groove to be locked and connected with the inner arm. The connecting outer arm is positioned below the fixed frame body, the long groove is opposite to the arc-shaped groove, the fixed block 43 is arranged in the connecting outer arm, and the locking screw penetrates through the arc-shaped groove and the long groove and is screwed into the fixed block to fix the fixed frame body and the connecting outer arm.

The inner ring of the joint bearing is internally penetrated with a connecting assembly, the axis of the inner ring is kept parallel relative to the projector fixing frame, and the axis of the adjusting screw rod is vertical to the axis of the outer ring. The connecting assembly comprises a pin tube 11 and a pin 18, the pin tube is inserted into the inner ring, the end part of the pin tube is inserted into a counter bore of the rotary seat, and the pin penetrates out of the pin tube and is screwed into a threaded hole of the rotary seat.

And adjusting the height of the main body pipe and the extension length of the connecting arm according to the installation height of the projector and the position of the fixing hole on the projector, and determining the position of the end part of the connecting inner arm. Fix projecting apparatus and gallows mutually earlier, the initial parallel of keeping fixed support body and intermediate disc, fix the gallows to the ceiling through the top fixed disk after that, then adjust the relative main part pipe rotation of intermediate disc for the projection direction of projecting apparatus is towards the place ahead curtain, fixed main part pipe and intermediate disc after that, adjust corresponding adjusting knob according to the projection angle of projecting apparatus again, change the position of the relative intermediate disc of fixed support body through rotating the adjusting knob, finely tune the projection angle of projecting apparatus. After the adjusting button is adjusted in place, the fixing pin is screwed to fix the adjusting button.

The above, only be the utility model discloses a preferred embodiment, it is not right the utility model discloses do any restriction, all according to the utility model discloses the technical entity all still belongs to any simple modification, change and equivalent transformation of doing above embodiment the utility model discloses technical scheme's protection scope.

Claims

1. A projector hanging bracket is characterized by comprising a top fixing disc (1), a projector fixing frame and a main body tube (2), wherein the projector fixing frame is connected with a middle disc (7) through a joint bearing, and the middle disc is connected with the main body tube; the joint bearings are at least three and are arranged symmetrically relative to the center of the middle disc, each joint bearing comprises an inner ring (38) with an outer spherical surface and an outer ring (12) with an inner spherical surface, the inner spherical surface of the outer ring and the outer spherical surface of the inner ring form a rolling friction pair, the outer ring is connected with an adjusting screw rod (19), and the middle disc is provided with an adjusting button (6) which is in threaded fit with the adjusting button.

2. The projector hanger as claimed in claim 1, wherein the inner ring has a connection assembly passing therethrough, the axis of the inner ring is parallel to the projector mount, the axis of the adjustment screw is perpendicular to the axis of the outer ring, and the axis of the adjustment screw is parallel to the axis of the main tube.

3. The projector hanger as claimed in claim 2, wherein a rotary seat (13) is fixed on the projector mount, the rotary seat is provided with a threaded hole, the axis of the threaded hole is parallel to the projector mount, and a counter bore is provided on the rotary seat corresponding to the threaded hole; the connecting assembly comprises a pin pipe (11) and a pin (18), the pin pipe is inserted into the inner ring, the end part of the pin pipe is inserted into the counter bore, and the pin penetrates out of the pin pipe and is screwed into the threaded hole of the rotary seat.

4. The projector hanger as claimed in claim 1, 2 or 3, wherein the intermediate plate is provided with a knob rotating hole (42), the knob has a knob portion and a cylinder (36), the cylinder is inserted into the rotating hole, the lower end of the rotating hole is provided with a lower counter bore, a bearing (37) is embedded in the lower counter bore, the end of the cylinder is provided with a clamping groove (10), a clamping spring (9) is clamped in the clamping groove, and the clamping spring limits the bearing.

5. The projector hanger as claimed in claim 4, wherein the adjusting knob has a threaded hole at an axis thereof, the adjusting screw has an external thread on an outer surface thereof, the adjusting screw is screwed into the threaded hole of the adjusting knob, and the position of the inner ring relative to the intermediate plate is adjusted by rotating the adjusting knob.

6. The hanger for projectors according to claim 1, 2 or 3, wherein the middle plate has a main tube mounting hole formed therein and an opening (26) formed therein such that the main tube mounting hole communicates with the outside of the middle plate, the main tube mounting hole has a circular shape, the middle plate has a radial screw hole formed therein at a position corresponding to the main tube mounting hole, and a main tube rotation locking nail (20) is inserted into the radial screw hole to lock the main tube.

7. The hanger according to claim 6, wherein the main tube mounting hole has a circular shape, the width of the opening is smaller than the diameter of the main tube mounting hole, the axial length of the main tube mounting hole is smaller than the thickness of the intermediate plate, the intermediate plate is provided with a step (41) protruding inward in the radial direction at the upper portion of the main tube mounting hole, the step surrounds a semicircular hole, and the diameter of the semicircular hole is equal to the width of the opening.

8. The projector hanging bracket as claimed in claim 1, 2 or 3, wherein the main tube is of a telescopic structure and comprises a main outer tube (3) and a main inner tube (5) which are sleeved with each other, a top fixing disc is fixed to the end of the main outer tube, a bottom fixing disc (25) is fixed to the bottom of the main inner tube, a ring groove (40) is formed in the periphery of the disc, and the disc is matched with the middle disc.

9. The projector hanger according to claim 8, wherein the main inner tube and the main outer tube are aluminum alloy tubes, the main inner tube has an axial rib (30) and a circular connecting rib (32) protruding inward, the axial rib has an axial groove (24), the main inner tube has a rectangular opening on its outer surface, the rectangular opening communicates with the axial groove, the axial rib has an axial hole (23), the circular connecting rib has a connecting hole (33), the main outer tube has a square connecting rib (31) protruding inward, the square connecting rib has a connecting hole, the square connecting rib has an outer shape matching the shape of the axial groove, the square connecting rib is inserted into the axial groove to form a guiding structure for the main outer tube to extend and retract relative to the main inner tube, the main outer tube has a radial circular hole corresponding to the axial hole, and the main outer tube and the main inner tube are fixed by a locking pin, the locking nail penetrates through the radial round hole and penetrates out of the axial hole, and the extending end is screwed into the locking block.

10. The projector hanging bracket as claimed in claim 1, 2 or 3, wherein the projector fixing bracket comprises a fixing bracket body (14) and a plurality of connecting arms connected with the fixing bracket body, the fixing bracket body is annular, a plurality of arc-shaped grooves (28) are formed in the annular ring, and one ends of the connecting arms are connected to the arc-shaped grooves; the connecting arm is of a telescopic structure and comprises a connecting inner arm (16) and a connecting outer arm (15) which are mutually inserted, and the connecting outer arm and the connecting inner arm are fixed through locking screws after being inserted.