CN215978522U

CN215978522U - Safe type beam column fixing device

Info

Publication number: CN215978522U
Application number: CN202122090428.8U
Authority: CN
Inventors: 郑明道; 郭培松; 徐自正; 陈先
Original assignee: Anhui Tiancheng Steel Structure Co ltd
Current assignee: Anhui Tiancheng Steel Structure Co ltd
Priority date: 2021-08-31
Filing date: 2021-08-31
Publication date: 2022-03-08
Anticipated expiration: 2031-08-31

Abstract

The utility model relates to the field of buildings, in particular to a safe beam column fixing device which comprises a beam column, a supporting structure, a swinging mechanism, a telescopic mechanism, a clamping mechanism and a shaking self-locking mechanism, wherein the bottom of the beam column is arranged vertical to the ground, the supporting structure is arranged on the ground or an engineering truck, the swinging mechanism and the shaking self-locking mechanism are both rotatably arranged on the supporting structure, the telescopic mechanism is fixedly arranged on the swinging mechanism, the utility model discloses a safe beam column fixing device, which is characterized in that a clamping mechanism for fixing a beam column is rotatably arranged on a telescopic mechanism, by designing the swing mechanism and the telescopic mechanism, the safety beam column fixing device replaces manual support, greatly reduces the operation risk, and improves the accuracy in fixing the beam column, through the detachable fixture of design, it is complicated to have solved the fixed operation of steel bar welding, and need the manual work to demolish the problem that the reinforcing bar is wasted time and energy after fixed the completion.

Description

Safe type beam column fixing device

Technical Field

The utility model relates to the field of buildings, in particular to a safe beam column fixing device.

Background

The beam column plays the post on the roof beam in the building, and the column bottom is the roof beam promptly, and the beam column is the stress column, and it constitutes a structural system with the frame roof beam, bears the power of top, when installation or welding beam column, needs advance location, pre-fixing, and the method has artifical support or steel bar welding fixed, and the complex danger of operation and inaccuracy easily takes place the incident, proposes the operation pain point to above background:

1. it is dangerous and inaccurate to manually hold the fixed beam column.

2. The steel bar welding and fixing operation is complex, and the steel bar needs to be manually removed after the fixing is completed, so that the operation risk is increased, and time and labor are wasted.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a safe beam column fixing device.

In order to achieve the purpose, the utility model adopts the following technical scheme:

the utility model provides a safe type beam column fixing device, includes the beam column, still includes bearing structure, swing mechanism, telescopic machanism, fixture and wave self-locking mechanism, and beam column bottom perpendicular to ground installation, bearing structure arrange in on ground or the machineshop car, swing mechanism and wave the equal rotation of self-locking mechanism and install on bearing structure, telescopic machanism fixed mounting is on swing mechanism for the fixture rotation of fixed beam column installs on telescopic machanism.

Further, bearing structure includes workstation, fixed plate and four supporting legs, and on ground or the machineshop car was arranged in to four supporting legs, workstation fixed mounting was on four supporting legs, and fixed plate fixed mounting is on the workstation, be provided with first backup pad and second backup pad on the fixed plate, first backup pad and swing mechanism rotate to be connected, and the second backup pad rotates with wave self-locking mechanism to be connected, and the annular is provided with a plurality of first spacing holes on the second backup pad lateral surface, and a plurality of first spacing holes are pegged graft with wave self-locking mechanism.

Further, every the supporting leg all is including supporting the grade pan, rotate mediation post and two and rotate half bases, it has the internal thread to support the grade pan upper end to set up, it is equipped with the external screw thread to rotate mediation post lower part, support the grade pan and rotate mediation post threaded connection, it has spacing annular to rotate mediation post upper portion, two rotate half base opposition laminating covers establish and mediate post upper portion annular in rotating, every rotates half base upper end and all is provided with a semicircle post, per two rotate half base and constitute a cylinder to the back upper end, four turnings in workstation bottom all are provided with the circular slot, four cylinders are fixed mounting in four circular slots in proper order.

Further, swing mechanism includes initiative swing arm, driven swing arm, the sleeve, dwang and first axis of rotation, the one end of dwang is provided with the spline, the one end of initiative swing arm is provided with the keyway, the spline joint is in the keyway, the other end of dwang rotates and installs in the second backup pad, first axis of rotation rotates and installs in first backup pad and second backup pad, driven swing arm's bottom is rotated and is installed in first axis of rotation, the sleeve slip cap is established on driven swing arm, be provided with the rotary column on the sleeve, the other end of initiative swing arm rotates and installs on the rotary column, the spacing hole of a plurality of seconds has been seted up on the driven swing arm, the grafting of spacing hole of a plurality of seconds and telescopic machanism.

Further, telescopic machanism includes the regulating arm, flexible arm and two adjusting nut, the pot head of regulating arm is established on driven swing arm, the other pot head of regulating arm is established on flexible arm, the spacing hole of a plurality of third has been seted up on the flexible arm, a plurality of regulation holes have been seted up to correspondence on the regulating arm, and the regulation hole is provided with the screw thread, two adjusting nut respectively fixed mounting in two of them regulating hole, and one of them adjusting nut pegs graft in one of them third is spacing downthehole, another adjusting nut pegs graft in one of them second is spacing downthehole, flexible arm end is provided with the hinge and props up with fixture rotation and connects.

Further, fixture includes splint and second axis of rotation, and splint and beam column slip joint are provided with the hinged-support on the splint, and the second axis of rotation is rotated and is installed on the hinged-support, and second axis of rotation and hinged-support rotate to be connected.

Further, wave self-locking mechanism and include the curved handle, rotate handle and stop nut, the one end fixed mounting of curved handle is on the dwang, the through-hole has been seted up to the other end of curved handle, the one end of rotating the handle is provided with inserts the post, it is provided with the screw ring platform to insert post inner, curved handle and rotation handle sliding connection, stop nut and curved handle's screw ring platform fixed connection, the post of inserting and one of them first spacing hole of rotating the handle are pegged graft, the other end of rotating the handle is provided with the non slipping spur, and the diameter of non slipping spur is greater than the through-hole diameter of curved handle.

The utility model has the beneficial effects that:

1. according to the safe beam column fixing device, the swing mechanism and the telescopic mechanism are designed, manual supporting is replaced, the operation risk is greatly reduced, and the accuracy in beam column fixing is improved.

2. According to the safe beam column fixing device, the detachable clamping mechanism is designed, so that the problems that the reinforcing steel bar welding and fixing operation is complex, and time and labor are wasted due to the fact that the reinforcing steel bar needs to be manually detached after the fixing is completed are solved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the embodiments of the present invention will be briefly described below.

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

FIG. 2 is an exploded perspective view of the present invention;

FIG. 3 is a schematic overall perspective view of the support structure of the present invention;

FIG. 4 is an exploded perspective view of the support leg of the support structure;

FIG. 5 is a schematic view of the overall structure of the swing mechanism of the present invention;

FIG. 6 is an exploded perspective view of the swing mechanism of the present invention;

FIG. 7 is an exploded perspective view of the telescoping mechanism of the present invention;

FIG. 8 is an exploded perspective view of the clamping mechanism of the present invention;

FIG. 9 is an exploded perspective view of the rocking self-locking mechanism of the present invention;

in the figure:

1. a beam column;

2. a support structure; 2a, supporting legs; 2a1, supporting ground; 2a2, rotating adjusting column; 2a3, turning the half-base; 2b, a workbench; 2c, fixing plates; 2d, a first supporting plate; 2e, a second support plate; 2f, a first limiting hole;

3. a swing mechanism; 3a, driving swing arms; 3b, a driven swing arm; 3c, a key groove; 3d, a sleeve; 3e, rotating the column; 3f, rotating the rod; 3g, splines; 3h, a first rotating shaft; 3k, a second limiting hole;

4. a telescoping mechanism; 4a, an adjusting arm; 4b, adjusting nuts; 4c, adjusting holes; 4d, a telescopic arm; 4e, a third limiting hole; 4f, hinging and supporting;

5. a clamping mechanism; 5a, a splint; 5b, a hinged support; 5c, a second rotating shaft;

6. shaking the self-locking mechanism; 6a, bending a handle; 6b, rotating the handle; 6c, a limit nut; 6d and anti-slip columns.

Detailed Description

The technical scheme of the utility model is further explained by the specific implementation mode in combination with the attached drawings.

Wherein the showings are for the purpose of illustration only and are shown by way of illustration only and not in actual form, and are not to be construed as limiting the present patent; to better illustrate the embodiments of the present invention, some components of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product.

Referring to fig. 1 to 9, the safe beam column fixing device comprises a beam column 1, and further comprises a supporting structure 2, a swinging mechanism 3, a telescopic mechanism 4, a clamping mechanism 5 and a shaking self-locking mechanism 6, wherein the bottom of the beam column 1 is installed perpendicular to the ground, the supporting structure 2 is arranged on the ground or an engineering vehicle, the swinging mechanism 3 and the shaking self-locking mechanism 6 are installed on the supporting structure 2 in a rotating mode, the telescopic mechanism 4 is fixedly installed on the swinging mechanism 3, and the clamping mechanism 5 for fixing the beam column 1 is installed on the telescopic mechanism 4 in a rotating mode. In construction, in order to avoid the inclination of the beam column 1, the beam column 1 needs to be fixed firstly, then the welding installation is carried out on the beam column 1, the supporting structure 2 is arranged on the ground or an engineering vehicle with a proper distance, the device needs to be placed horizontally, therefore, a supporting leg 2a with adjustable height is arranged, the supporting leg 2a is regulated to be horizontal, then a regulating arm 4a is sleeved on a driving swing arm 3a to regulate the required length, a regulating nut 4b is inserted into one of the second limiting holes 3k, the regulating nut 4b is rotated to fix a regulating nut 4b in one of the regulating holes 4c, so that the driving swing arm 3a and the regulating arm 4a are fixed, similarly, a telescopic arm 4d is sleeved in the regulating arm 4a to regulate the required length, the regulating arm 4a and the telescopic arm 4d are fixed, a handle 6b is rotated, and the clamping mechanism 5 is connected with the telescopic mechanism 4 in a rotating way, therefore, the swing of the telescopic mechanism 4 drives the clamping mechanism 5 to be close to the beam column 1, the support of the beam column 1 is completed when the clamping mechanism 5 is completely attached to the beam column 1, the rotating handle 6b is pushed inwards at the moment, the rotating handle 6b is pushed into the corresponding first limiting hole 2f, the fixing of the device to the beam column 1 is completed, after the beam column 1 is installed and completed, the rotating handle 6b is shaken in the opposite direction until the telescopic mechanism 4 swings to a reachable position by a touching hand, an operator pulls out the reverse rotation of the adjusting nut 4b, then the telescopic arm 4d and the adjusting arm 4a are sequentially pulled out, and the disassembly of the device is completed.

Supporting structure 2 includes workstation 2b, fixed plate 2c and four supporting legs 2a, and on ground or the machineshop car was arranged in to four supporting legs 2a, workstation 2b fixed mounting was on four supporting legs 2a, and fixed plate 2c fixed mounting is on workstation 2b, be provided with first backup pad 2d and second backup pad 2e on the fixed plate 2c, first backup pad 2d rotates with swing mechanism 3 and connects, and second backup pad 2e rotates with wave self-locking mechanism 6 and connects, and the annular is provided with a plurality of first spacing holes 2f on the 2e lateral surface of second backup pad, and a plurality of first spacing holes 2f are pegged graft with wave self-locking mechanism 6. The supporting structure 2 can be placed on the ground or an engineering vehicle according to the working environment, and for better fixing the beam column 1, the device needs to be horizontally placed, so that the supporting legs 2a with adjustable height are arranged.

Every supporting leg 2a all includes support land 2a1, rotate and mediate post 2a2 and two and rotate half base 2a3, support land 2a1 upper end and seted up the internal thread, it is equipped with the external screw thread to rotate and mediate post 2a2 lower part, support land 2a1 and rotate and mediate post 2a2 threaded connection, it has seted up spacing annular to rotate and mediate post 2a2 upper portion, two rotate half base 2a3 opposition laminating cover and establish in rotating and mediating post 2a2 upper portion annular, every rotates half base 2a3 upper end and all is provided with a semicircle post, every two rotates half base 2a3 opposition back upper end and constitutes a cylinder, four turnings in workstation 2b bottom all are provided with the circular slot, four cylinders are fixed mounting in proper order in four circular slots. A through hole is formed in the rotation adjusting column 2a2, the rotation adjusting column 2a2 can rotate in the two rotation half bases 2a3, an iron rod is inserted into the through hole of the rotation adjusting column 2a2, and the height of the supporting leg 2a is adjusted by rotating the iron rod.

Swing mechanism 3 includes initiative swing arm 3a, driven swing arm 3b, sleeve 3d, dwang 3f and first axis of rotation 3h, the one end of dwang 3f is provided with spline 3g, the one end of initiative swing arm 3a is provided with keyway 3c, the joint of spline 3g is in keyway 3c, the other end of dwang 3f is rotated and is installed on second backup pad 2e, first axis of rotation 3h is rotated and is installed on first backup pad 2d and second backup pad 2e, driven swing arm 3 b's bottom is rotated and is installed on first axis of rotation 3h, sleeve 3d slip cap is established on driven swing arm 3b, be provided with rotary column 3e on the sleeve 3d, the other end of initiative swing arm 3a is rotated and is installed on rotary column 3e, the spacing hole 3k of a plurality of seconds has been seted up on driven swing arm 3b, the spacing hole 3k of a plurality of seconds is pegged graft with telescopic machanism 4. Dwang 3f and the one end that initiative swing arm 3a is connected are provided with spline 3g, spline 3g does not pass initiative swing arm 3a, dwang 3f terminal surface is provided with the screw hole, use the screw fixation to prevent dwang 3f slippage, dwang 3f rotates the other end swing that drives initiative swing arm 3a simultaneously, initiative swing arm 3 a's the other end and sleeve 3d rotate to be connected, when initiative swing arm 3a swings, it slides on driven swing arm 3b to drive sleeve 3d, driven swing arm 3b bottom and first rotation axis 3h rotate to be connected, consequently, sleeve 3d drives driven swing arm 3b swing, according to the fixed height of required centre gripping, adjust driven swing arm 3 b's swing angle, make that this device can be better fixed with beam column 1.

The telescopic mechanism 4 comprises an adjusting arm 4a, a telescopic arm 4d and two adjusting nuts 4b, one end of the adjusting arm 4a is sleeved on the driven swing arm 3b, the other end of the adjusting arm 4a is sleeved on the telescopic arm 4d, a plurality of third limiting holes 4e are formed in the telescopic arm 4d, a plurality of adjusting holes 4c are correspondingly formed in the adjusting arm 4a, the adjusting holes 4c are provided with threads, the two adjusting nuts 4b are fixedly installed in the two adjusting holes 4c respectively, one adjusting nut 4b is inserted into one of the third limiting holes 4e, the other adjusting nut 4b is inserted into one of the second limiting holes 3k, the tail end of the telescopic arm 4d is provided with a hinge 4f, and the hinge 4f is rotatably connected with the clamping mechanism 5. The environment is complicated in the construction operation, needs to select comparatively smooth bottom surface installation this device, consequently designs telescopic machanism 4, according to the distance between 1 and this device of beam column, through changing the position adjustment telescopic machanism 4 of adjusting nut 4b in spacing hole 3k of second and the spacing hole 4e of third to suitable length, and this device and 1 butt joint centre gripping of beam column are fixed to rethread swing mechanism 3 completion.

Fixture 5 includes splint 5a and second axis of rotation 5c, and splint 5a and the slip joint of beam column 1 are provided with hinged-support 5b on splint 5a, and second axis of rotation 5c rotates and installs on hinged-support 5b, and second axis of rotation 5c and hinged 4f rotate and connect. The size of splint 5a designs according to the specification of beam column 1, and this device only needs to pull down second axis of rotation 5c, changes the splint 5a of suitable size when the fixed beam column 1 of unable specification of centre gripping.

Wave self-locking mechanism 6 and include curved handle 6a, rotate handle 6b and stop nut 6c, the one end fixed mounting of curved handle 6a is on dwang 3f, the through-hole has been seted up to curved handle 6 a's the other end, the one end of rotating handle 6b is provided with inserts the post, it is provided with the screw ring platform to insert the post inner, curved handle 6a and rotation handle 6b sliding connection, stop nut 6c and curved handle 6 a's screw ring platform fixed connection, the post of inserting and one of them first spacing hole 2f of rotating handle 6b are pegged graft, the other end of rotating handle 6b is provided with non slipping spur 6d, and the diameter of non slipping spur 6d is greater than the through-hole diameter of curved handle 6 a. Considering that the self-weight of the telescopic mechanism 4 will affect the position of the swing mechanism 3, the swing self-locking mechanism 6 is designed, when the swing mechanism 3 needs to be adjusted, an operator pulls the anti-skid column 6d outwards, the bent handle 6a and the rotating handle 6b form a crank at the moment, when the swing mechanism 3 is adjusted to a target position, the operator presses the anti-skid column 6d inwards, the rotating handle 6b is inserted into the corresponding first limiting hole 2f, the self-locking of the device is completed, and the telescopic mechanism 4 is prevented from swinging downwards due to the self-weight.

The working principle is as follows: in construction, in order to avoid the inclination of the beam column 1, the beam column 1 needs to be fixed firstly, then the welding installation is carried out, the supporting structure 2 is arranged on the ground or an engineering vehicle with a proper distance, the device needs to be placed horizontally, therefore, a supporting leg 2a with adjustable height is arranged, a through hole is arranged on a rotating adjusting column 2a2, the rotating adjusting column 2a2 can rotate in two rotating half bases 2a3, an iron rod is inserted into the through hole of the rotating adjusting column 2a2, the adjusting of the height of the supporting leg 2a is completed by rotating the iron rod, then an adjusting arm 4a is sleeved on an active swing arm 3a to adjust the required length, an adjusting nut 4b is inserted into one of second limiting holes 3k, the adjusting nut 4b is rotated to fix the adjusting nut 4b in one of adjusting holes 4c, so that the active swing arm 3a and the adjusting arm 4a are fixed, and a telescopic arm 4d is sleeved in the adjusting arm 4a in the same way, adjusting the required length, fixing the adjusting arm 4a and the telescopic arm 4d, considering that the dead weight of the telescopic mechanism 4 will affect the position of the swing mechanism 3, designing the swing self-locking mechanism 6, when the swing mechanism 3 needs to be adjusted, an operator pulls the anti-skid post 6d outwards, at this time, the bent handle 6a and the rotating handle 6b form a crank, when the swing mechanism 3 is adjusted to the target position, the operator presses the anti-skid post 6d inwards, inserts the rotating handle 6b into the corresponding first limit hole 2f, completing the self-locking of the device, preventing the telescopic mechanism 4 from swinging downwards due to the dead weight, because the clamping mechanism 5 is rotatably connected with the telescopic mechanism 4, the telescopic mechanism 4 swings to drive the clamping mechanism 5 to approach to the beam column 1, when the clamping mechanism 5 is completely attached to the beam column 1, the rotating handle 6b is pushed inwards, and the rotating handle 6b is pushed into the corresponding first limit hole 2f, the fixing of the beam column 1 by the device is finished, after the beam column 1 is installed, the rotating handle 6b is shaken in the opposite direction until the telescopic mechanism 4 swings to a position where a touch hand can reach, the operator pulls out the adjusting nut 4b in the opposite direction, then the telescopic arm 4d and the adjusting arm 4a are sequentially pulled out, and the device is disassembled.

Claims

1. The utility model provides a safe type beam column fixing device, includes beam column (1), its characterized in that: still include bearing structure (2), swing mechanism (3), telescopic machanism (4), fixture (5) and wave self-locking mechanism (6), beam column (1) bottom perpendicular to ground installation, on ground or the machineshop car was arranged in to bearing structure (2), swing mechanism (3) and wave self-locking mechanism (6) and all rotate and install on bearing structure (2), telescopic machanism (4) fixed mounting is on swing mechanism (3), fixture (5) for fixed beam column (1) rotate and install on telescopic machanism (4).

2. The safety beam column fixing device of claim 1, wherein: bearing structure (2) are including workstation (2b), fixed plate (2c) and four supporting legs (2a), and ground or machineshop car are arranged in to four supporting legs (2a), workstation (2b) fixed mounting on four supporting legs (2a), fixed plate (2c) fixed mounting on workstation (2b), be provided with first backup pad (2d) and second backup pad (2e) on fixed plate (2c), first backup pad (2d) and swing mechanism (3) rotate to be connected, second backup pad (2e) with wave self-locking mechanism (6) and rotate to be connected, the annular is provided with a plurality of first spacing holes (2f) on second backup pad (2e) lateral surface, a plurality of first spacing holes (2f) with wave self-locking mechanism (6) and peg graft.

3. The safety beam column fixing device of claim 2, wherein: every supporting leg (2a) all includes support ground plate (2a1), rotate and mediate post (2a2) and two and rotate half base (2a3), support ground plate (2a1) upper end and seted up the internal thread, it is equipped with the external screw thread to rotate and mediate post (2a2) lower part, support ground plate (2a1) and rotate and mediate post (2a2) threaded connection, it has seted up spacing annular to rotate and mediate post (2a2) upper portion, two rotate half base (2a3) opposition laminating cover establish in rotating and mediating post (2a2) upper portion annular, every rotates half base (2a3) upper end and all is provided with a semicircle post, the upper end constitutes a cylinder after per two rotate half base (2a3) opposition, four turnings in workstation (2b) bottom all are provided with the circular slot, four cylinders are fixed mounting in four circular slots in proper order.

4. A secure beam and column fixing device as claimed in claim 3, wherein: the swing mechanism (3) comprises a driving swing arm (3a), a driven swing arm (3b), a sleeve (3d), a rotating rod (3f) and a first rotating shaft (3h), one end of the rotating rod (3f) is provided with a spline (3g), one end of the driving swing arm (3a) is provided with a key groove (3c), the spline (3g) is connected in the key groove (3c) in a clamping manner, the other end of the rotating rod (3f) is rotatably arranged on a second supporting plate (2e), the first rotating shaft (3h) is rotatably arranged on a first supporting plate (2d) and a second supporting plate (2e), the bottom end of the driven swing arm (3b) is rotatably arranged on the first rotating shaft (3h), the sleeve (3d) is sleeved on the driven swing arm (3b) in a sliding manner, a rotating column (3e) is arranged on the sleeve (3d), the other end of the driving swing arm (3a) is rotatably arranged on the rotating column (3e), a plurality of second limiting holes (3k) are formed in the driven swing arm (3b), and the second limiting holes (3k) are connected with the telescopic mechanism (4) in an inserting mode.

5. The safety beam column fixing device of claim 4, wherein: the telescopic mechanism (4) comprises an adjusting arm (4a), a telescopic arm (4d) and two adjusting nuts (4b), one end of the adjusting arm (4a) is sleeved on the driven swing arm (3b), the other end of the adjusting arm (4a) is sleeved on the telescopic arm (4d), a plurality of third limiting holes (4e) are formed in the telescopic arm (4d), a plurality of adjusting holes (4c) are correspondingly formed in the adjusting arm (4a), the adjusting holes (4c) are provided with threads, two adjusting nuts (4b) are respectively and fixedly arranged in the two adjusting holes (4c), and one adjusting nut (4b) is inserted in one third limiting hole (4e), the other adjusting nut (4b) is inserted in one second limiting hole (3k), the tail end of the telescopic arm (4d) is provided with a hinged support (4f), and the hinged support (4f) is rotatably connected with the clamping mechanism (5).

6. The safety beam column fixing device of claim 5, wherein: fixture (5) are including splint (5a) and second axis of rotation (5c), and splint (5a) and beam column (1) slip joint are provided with hinged-support (5b) on splint (5a), and second axis of rotation (5c) are rotated and are installed on hinged-support (5b), and second axis of rotation (5c) and hinged-support (4f) rotate and are connected.

7. The safety beam column fixing device of claim 6, wherein: wave self-locking mechanism (6) including curved handle (6a), rotate handle (6b) and stop nut (6c), the one end fixed mounting of curved handle (6a) is on dwang (3f), the through-hole has been seted up to the other end of curved handle (6a), the one end of rotating handle (6b) is provided with inserts the post, insert the post inner and be provided with the screw ring platform, curved handle (6a) and rotation handle (6b) sliding connection, the screw ring platform fixed connection of stop nut (6c) and curved handle (6a), the post of inserting of rotating handle (6b) is pegged graft with one of them first spacing hole (2f), the other end of rotating handle (6b) is provided with anti-skidding post (6d), and the diameter of post (6d) is greater than the through-hole diameter of curved handle (6 a).