CN212806849U

CN212806849U - Gear parameter rapid detection tool

Info

Publication number: CN212806849U
Application number: CN202022176775.8U
Authority: CN
Inventors: 白武; 甘伟浩; 陆鑫
Original assignee: Shanghai Wanzhong Industrial Co ltd
Current assignee: Shanghai Wanzhong Industrial Co ltd
Priority date: 2020-09-28
Filing date: 2020-09-28
Publication date: 2021-03-26
Anticipated expiration: 2030-09-28

Abstract

The utility model relates to a utensil is examined fast to gear parameter, it includes the operation panel, the fixed platform of placing that is provided with on the lateral wall of operation panel, it keeps away from the fixed a plurality of locating levers that are provided with on the lateral wall of operation panel to place the platform, the one end that the locating lever is close to the operation panel is provided with positioning mechanism, the lateral wall of operation panel slides in the position department of being close to the platform of placing and is provided with the external amesdial, the lateral wall of operation panel slides in the position department for the external amesdial and is provided with the tooth width amesdial. This application has the effect of efficiency when promoting the detection gear.

Description

Gear parameter rapid detection tool

Technical Field

The application relates to the field of gear checking tools, in particular to a gear parameter quick checking tool.

Background

After the gear is manufactured, the gear needs to be detected to detect the gear with unqualified size.

In the related art, when a gear is detected, parameters such as the tooth width and the outer diameter of the gear need to be detected one by using a dial indicator, and the dial indicator is a length measuring instrument which converts general linear displacement (linear motion) into rotary motion of a pointer through a gear or a lever and then reads on a dial. Dial gauges are widely used indicating gauges for precision measurements. It belongs to a comparison measuring tool, and can only measure relative numerical values, but can not measure absolute numerical values. Mainly used for checking the shape and position error of the workpiece.

In view of the above-mentioned related art, the inventors have considered that there is a drawback that the efficiency in performing detection is low.

SUMMERY OF THE UTILITY MODEL

In order to promote the efficiency of detecting the gear, this application provides a utensil is examined fast to gear parameter.

The application provides a gear parameter examines utensil fast adopts following technical scheme:

the gear parameter rapid detection tool comprises an operation table, wherein a placing table is fixedly arranged on the side wall of the operation table, a plurality of positioning rods are fixedly arranged on the side wall, away from the operation table, of the placing table, one end, close to the operation table, of each positioning rod is provided with a positioning mechanism, an outer dial indicator is arranged on the side wall of the operation table in a sliding mode at a position, close to the placing table, of the side wall, and a tooth width dial indicator is arranged on the side wall of the operation table in a sliding mode at a position, relative to the outer dial indicator, of the.

By adopting the technical scheme, when the gear is detected, the standard part is firstly penetrated on the positioning rod and is fixed on the placing table through the positioning mechanism, the outer diameter and the tooth width of the standard part are measured through the outer dial indicator and the tooth width dial indicator at the moment, then the standard part is taken down from the positioning rod, the outer dial indicator and the tooth width dial indicator are reset to zero, at the moment, the plurality of gears to be detected are penetrated on the positioning rod in a one-to-one correspondence manner, the gear to be detected is fixed on the placing table through the positioning mechanism, and at the moment, the outer dial indicator is moved, so that the detecting head of the outer dial indicator is sequentially contacted with the top circular side walls of the plurality of gears to be detected, and the difference value between the outer diameter of the gear to be; after the external diameter measurement operation of the gear to be measured is completed, the tooth width dial indicator can be moved, so that a detection head of the tooth width dial indicator is sequentially contacted with the side walls of the plurality of gears to be measured far away from the placing table, and the difference value of the tooth width of the gear to be measured and the standard part is obtained. So set up for but a plurality of gear that await measuring of gear parameter quick detection utensil in this application simultaneous measurement is favorable to promoting the efficiency that detects the gear.

Preferably, the positioning mechanism comprises a plurality of fixing columns and a plurality of abutting columns, the fixing columns are fixedly arranged on the peripheral side wall of the positioning rod, the abutting columns are sleeved on the fixing columns in a sliding mode, first elastic pieces are arranged in the abutting columns, one ends of the first elastic pieces abut against the side wall of the positioning rod, and one ends, far away from the positioning rod, of the first elastic pieces are fixedly arranged on the inner side wall, close to the positioning rod, of the abutting columns.

Through adopting above-mentioned technical scheme, during the fixed gear that awaits measuring, at first press a plurality of butt posts, make the butt post overcome the elasticity of first elastic component and slide towards the locating lever place direction on the fixed column, when the butt post can't continue to remove, can wear to establish the gear that awaits measuring on the locating lever, until the lateral wall of the gear that awaits measuring and the lateral wall butt of placing the platform and keeping away from the operation panel, can loosen the butt post this moment, make the butt post remove towards the direction of keeping away from the locating lever under the effect of the elastic restoring force of first elastic component, a plurality of butt posts on a locating lever are common with the inside wall butt of the gear that awaits measuring, thereby fix the gear that awaits measuring and place the bench, and the gear that awaits measuring this. So set up for when measuring at every turn, gear to be measured and reference column can keep coaxial state of placing, thereby when having reduced because of placing gear to be measured, gear to be measured's position is difficult to keep unanimous and cause the too big probability of measuring error with the position of standard component, is favorable to promoting the accuracy of examining utensil when detecting the gear fast of gear parameter in this application.

Preferably, an elastic cushion layer is fixedly arranged on the side wall of the abutting column away from the positioning rod.

Through adopting above-mentioned technical scheme, when the inside wall butt of butt post and gear to be measured, the elastic cushion layer provides the buffering for gear to be measured's inside wall, has reduced the probability that gear to be measured is worn and torn by the butt post, is favorable to promoting the protectiveness of butt post to gear to be measured.

Preferably, the operation panel is provided with the spout in the both sides of placing the platform, it is provided with first slider to slide in the spout, the external micrometer slides and wears to establish in first slider, the detecting head of external micrometer sets up towards the locating lever place direction, keeps away from it is provided with the second slider to slide in the spout of first slider, is provided with the supporting shoe on the lateral wall that the operation panel was kept away from to the second slider, the tooth width micrometer wears to establish in the supporting shoe, the detecting head of tooth width micrometer sets up towards placing the platform place direction.

Through adopting above-mentioned technical scheme, during the external micrometer that slides, control first slider and slide in the spout, can control the external micrometer and measure the external diameter of each gear that awaits measuring. When the tooth width micrometer slides, the second sliding block is controlled to slide in the sliding groove far away from the first sliding block, and the tooth width of each gear to be measured can be controlled to be measured by the tooth width micrometer. So set up, be favorable to promoting the stability of external micrometer and tooth width micrometer when sliding.

Preferably, a sliding column is fixedly arranged on the side wall, far away from the operating platform, of the second sliding block, the supporting block is arranged on the sliding column in a sliding and penetrating mode, and a fastener for fixing the supporting block is arranged on the side wall of the supporting block in a penetrating mode.

Through adopting above-mentioned technical scheme, when measuring the gear of different tooth width specifications, at first not hard up fastener, and control the supporting shoe and slide on the slip post, so that the tooth width micrometer can contact with the gear lateral wall of different tooth widths, thereby obtain the tooth width data of a plurality of gears of different tooth widths, after finishing measuring, can fix the supporting shoe on the slip post through the fastener, thereby avoid the supporting shoe to slide down from the slip post under the effect of gravity and lead to the detecting head of tooth width micrometer and place the platform touching and damage, be favorable to promoting the whole application of the quick utensil of examining of gear parameter in this application.

Preferably, a placing groove is formed in the side wall, away from the positioning rod, of the first sliding block, the outside dial indicator is arranged in the placing groove in a sliding mode in a penetrating mode, a second elastic piece is sleeved on the outside dial indicator, one end, close to the positioning column, of the second elastic piece is fixedly connected with the bottom side wall of the placing groove, a limiting piece is fixedly arranged on the position, away from the positioning rod, of the peripheral side wall of the outside dial indicator in a penetrating mode, and one end, away from the positioning rod, of the second elastic piece is abutted to the limiting piece.

Through adopting above-mentioned technical scheme, when the technical staff measured the gear that awaits measuring on a plurality of locating levers, at first slide first slider to the position department that is close to the gear that awaits measuring, then press the external dial indicator, spacing piece extrusion second elastic component this moment, make the external dial indicator and spacing piece overcome the elasticity of second elastic component and move towards the gear that awaits measuring, when the detecting head of external dial indicator and the external diameter lateral wall butt of the gear that awaits measuring, can carry out the reading, the back is accomplished in the reading, can stop pressing the external dial indicator, the second elastic component makes spacing piece move towards the direction of keeping away from the locating lever through the elastic restoring force of self, spacing piece drives external dial indicator simultaneous movement simultaneously, when the external dial indicator stopped moving, can continue to move first slider, in order to continue to measure other gears that await measuring. So set up for the technical staff need not manually to reset the external dial indicator after finishing to the external diameter measurement of a gear that awaits measuring, is favorable to promoting the measurement of the quick utensil of examining of gear parameter in this application.

Preferably, a shifting sheet is fixedly arranged on the peripheral side wall of the abutting column.

Through adopting above-mentioned technical scheme, the technical staff accessible removes the plectrum and drives the butt joint post and slide towards the reference column, is favorable to promoting the convenience when removing the butt joint post.

Preferably, the placing table is fixedly provided with a flexible cushion layer on the peripheral side of the positioning rod.

Through adopting above-mentioned technical scheme, when the gear that awaits measuring is placed placing the bench, the flexible cushion layer can provide the buffering to the gear that awaits measuring, reduces the gear that awaits measuring and is placed the probability of platform wearing and tearing, is favorable to promoting to place the platform to the protectiveness of gear that awaits measuring.

In summary, the present application includes at least one of the following beneficial technical effects:

by arranging a plurality of positioning rods on the placing table, arranging a positioning mechanism at one end of each positioning rod, arranging an outer diameter dial indicator on the operating table in a sliding manner, arranging a tooth width dial indicator on the side wall of the operating table in a sliding manner, when the gear is detected, firstly, the standard part is arranged on the positioning rods in a penetrating manner, and is fixed on the placing table through a positioning mechanism, at the moment, the outer diameter and the tooth width of the standard component are measured through an outer diameter dial indicator and a tooth width dial indicator, then the standard piece is taken down from the positioning rod, the outside dial indicator and the tooth width dial indicator are reset to zero, at the moment, a plurality of gears to be measured are correspondingly arranged on the positioning rod in a penetrating way one by one, the gear to be measured is fixed on the placing table through the positioning mechanism, at the moment, the outside dial indicator is moved, enabling a probe of the outside dial indicator to be sequentially contacted with the top circular side walls of the teeth of the plurality of gears to be tested, and obtaining the difference value between the outside diameter of the gear to be tested and the standard part; after the external diameter measurement operation of the gear to be detected is completed, the tooth width dial indicator can be moved, so that a detecting head of the tooth width dial indicator is sequentially contacted with the side walls of the plurality of gears to be detected, which are far away from the placing table, and therefore the difference value of the tooth width of the gear to be detected and the standard part is obtained, and the efficiency of detecting the gear is improved;

through set up a plurality of fixed columns and a plurality of butt post on positioning mechanism, the fixed column is fixed to be set up on the week lateral wall of locating lever, butt post slip cap is established on the fixed column, be provided with first elastic component in the butt post, when making the fixed gear that awaits measuring, press a plurality of butt posts, when the butt post can't continue to remove, can wear to establish the gear that awaits measuring on the locating lever, until the lateral wall of the gear that awaits measuring with place the platform and keep away from the lateral wall butt of operation panel, can loosen the butt post this moment, make the butt post move towards the direction of keeping away from the locating lever under the effect of the elastic restoring force of first elastic component, a plurality of butt posts on the locating lever jointly with the inside wall butt of the gear that awaits measuring, thereby fix the gear that awaits measuring on placing the platform. Due to the arrangement, the accuracy of the gear parameter quick detection tool in the application in detecting the gear is improved;

through fixed setting plectrum on the butt joint post for the technical staff accessible removes the plectrum and drives the butt joint post and slide towards the reference column, is favorable to promoting the convenience when removing the butt joint post.

Drawings

Fig. 1 is a schematic overall structure diagram of an embodiment of the present application.

Fig. 2 is an enlarged schematic view of a portion a in fig. 1.

Description of reference numerals: 1. an operation table; 2. a placing table; 3. positioning a rod; 4. a positioning mechanism; 41. a butting post; 42. fixing a column; 5. a first elastic member; 6. an elastic cushion layer; 7. a shifting sheet; 8. a flexible cushion layer; 9. a chute; 10. a first slider; 11. an outside dial gauge; 12. a placement groove; 13. a second elastic member; 14. a limiting sheet; 15. a second slider; 16. a sliding post; 17. a support block; 18. a tooth width dial gauge; 19. a fastener.

Detailed Description

The present application is described in further detail below with reference to figures 1-2.

The embodiment of the application discloses utensil is examined fast to gear parameter. Referring to fig. 1 and 2, the gear parameter rapid checking fixture comprises a rectangular parallelepiped operating console 1, a rectangular parallelepiped placing platform 2 is welded to a top side wall of the operating console 1, and a plurality of cylindrical positioning rods 3 are uniformly and vertically welded to the top side wall of the placing platform 2 along a length direction, wherein in this embodiment, the number of the positioning rods 3 may be four. The positioning mechanism 4 is uniformly arranged on the peripheral side wall of the positioning rod 3 at a position close to the placing table 2.

The positioning mechanism 4 includes a plurality of cylindrical fixing posts 42 and a plurality of cylindrical abutting posts 41, and in this embodiment, the number of the fixing posts 42 and the abutting posts 41 may be four. The fixed column 42 is uniformly welded on the peripheral side wall of the positioning rod 3, and the fixed column 42 is coaxially sleeved with the first elastic member 5, in this embodiment, the first elastic member 5 may be a spring. One end of the first elastic member 5 is disposed in contact with the peripheral side wall of the positioning rod 3. The abutting column 41 is coaxially and slidably sleeved on the fixed column 42, and one end of the first elastic piece 5, which is far away from the positioning rod 3, abuts against the inner side wall, which is close to the positioning rod 3, of the abutting column 41. When fixing the gear that awaits measuring, at first press a plurality of butt columns 41, make butt column 41 overcome the elasticity of first elastic component 5 and slide towards the orientation of locating lever 3 place on fixed column 42, when butt column 41 can't continue to remove, can wear to establish on locating lever 3 the gear that awaits measuring, until the lateral wall of the gear that awaits measuring with place the platform 2 and keep away from the lateral wall butt of operation panel 1, can loosen butt column 41 this moment, make butt column 41 move towards the orientation of keeping away from locating lever 3 under the effect of the elastic restoring force of first elastic component 5, a plurality of butt columns 41 on one locating lever 3 are common with the inside wall butt of the gear that awaits measuring, thereby fix the gear that awaits measuring on placing platform 2, and the gear that awaits measuring this moment is coaxial with fixed column 42 and is placed. So set up for when measuring at every turn, gear to be measured and reference column can keep coaxial state of placing, thereby when having reduced because of placing gear to be measured, gear to be measured's position is difficult to keep unanimous and cause the too big probability of measuring error with the position of standard component, is favorable to promoting the accuracy of examining utensil when detecting the gear fast of gear parameter in this application.

The abutting column 41 is provided with an elastic cushion layer 6 on the side wall far away from the fixed column 42 through glue, and in this embodiment, the material of the elastic cushion layer 6 may be isoprene rubber. When the inside wall butt of butt post 41 and the gear that awaits measuring, elastic cushion 6 provides the buffering for the inside wall of the gear that awaits measuring, has reduced the probability that the gear that awaits measuring is worn and torn by butt post 41, is favorable to promoting the protectiveness of butt post 41 to the gear that awaits measuring.

The rectangular shifting piece 7 is fixedly welded on the peripheral side wall of the abutting column 41 at the position close to the positioning rod 3, so that a technician can drive the abutting column 41 to slide towards the positioning column by moving the shifting piece 7, and convenience in moving the abutting column 41 is improved.

The side wall of the top of the placing table 2 is provided with a round flexible cushion layer 8 through glue coaxially fixed on the periphery of the positioning rod 3, and in the embodiment, the flexible cushion layer 8 can be made of silica gel. When the gear that awaits measuring is placed placing platform 2 on, flexible bed course 8 can provide the buffering to the gear that awaits measuring, reduces the gear that awaits measuring and is placed the probability of 2 wearing and tearing of platform, is favorable to promoting and places the protectiveness of platform 2 to the gear that awaits measuring.

Rectangular sliding grooves 9 are formed in the top side wall of the operating platform 1 along the length direction on two sides of the placing platform 2, and a first rectangular sliding block 10 is arranged in one sliding groove 9 in a sliding mode. An outside dial indicator 11 is arranged at one end, far away from the operating platform 1, of the first sliding block 10 in a penetrating mode, and a detection head of the outside dial indicator 11 faces the positioning rod 3. A circular placing groove 12 is formed in the side wall, away from the positioning rod 3, of the first sliding block 10, and the outer dial indicator 11 coaxially slides to be arranged in the placing groove 12 in a penetrating mode. The second elastic member 13 is disposed in the placing groove 12, and in this embodiment, the second elastic member 13 may be a spring. The second elastic piece 13 is coaxially sleeved on the outside dial indicator 11. The peripheral side wall of the outside dial indicator 11 is provided with a circular limiting sheet 14 at a position close to the placing groove 12 by coaxial welding. One end of the second elastic piece 13 is welded with the bottom side wall of the placing groove 12, and one end of the second elastic piece 13, which is far away from the positioning rod 3, is abutted against the limiting piece 14. When a technician measures gears to be measured on a plurality of positioning rods 3, firstly, the first sliding block 10 is slid to a position close to the gears to be measured, then the outside dial indicator 11 is pressed, at the moment, the limiting piece 14 extrudes the second elastic piece 13, the outside dial indicator 11 and the limiting piece 14 move towards the gears to be measured by overcoming the elastic force of the second elastic piece 13, when a detection head of the outside dial indicator 11 is abutted to the outside diameter side wall of the gears to be measured, reading can be carried out, after the reading is finished, the pressing of the outside dial indicator 11 can be stopped, the second elastic piece 13 enables the limiting piece 14 to move towards the direction far away from the positioning rods 3 through the elastic restoring force of the second elastic piece 13, meanwhile, the limiting piece 14 drives the outside dial indicator 11 to move together, when the outside dial indicator 11 stops moving, the first sliding block 10 can be continuously moved, so that other. So set up for the technical staff need not manually to reset external dial indicator 11 to the external diameter measurement back that finishes of a gear that awaits measuring, is favorable to promoting the measurement of the quick utensil of examining of gear parameter in this application.

A second slide block 15 in a cuboid shape is arranged in the slide groove 9 far away from the first slide block 10 in a sliding way. A cylindrical sliding column 16 is vertically welded on the top side wall of the second slider 15, a cuboid-shaped supporting block 17 is slidably arranged on the sliding column 16 in a penetrating manner, a tooth width dial indicator 18 is vertically and fixedly arranged on the top side wall of the supporting block 17 at a position far away from the sliding column 16 in a penetrating manner, and a detection head of the tooth width dial indicator 18 faces the operating platform 1. The side wall of the supporting block 17 far away from the tooth width dial indicator 18 is provided with a fastener 19 in a penetrating way, and in the embodiment, the fastener 19 can be a bolt. When measuring the gear of different tooth width specifications, at first not hard up fastener 19, and control supporting shoe 17 and slide on sliding column 16, so that the tooth width micrometer can contact with the gear lateral wall of different tooth widths, thereby obtain the tooth width data of a plurality of gears of different tooth widths, after finishing measuring, can fix supporting shoe 17 on sliding column 16 through fastener 19, thereby avoid supporting shoe 17 to slide down from sliding column 16 under the effect of gravity and lead to the detecting head of tooth width micrometer and place the platform 2 touching and damage, be favorable to promoting the whole application of the quick utensil of examining of gear parameter in this application.

The implementation principle of the gear parameter rapid checking fixture in the embodiment of the application is as follows: when the gear is detected, firstly, the standard part is arranged on the positioning rod 3 in a penetrating mode and is fixed on the placing table 2 through the positioning mechanism 4, the outer diameter and the tooth width of the standard part are measured through the outer dial indicator 11 and the tooth width dial indicator 18 at the moment, then the standard part is taken down from the positioning rod 3, the outer dial indicator 11 and the tooth width dial indicator 18 are reset to zero, at the moment, a plurality of gears to be detected are arranged on the positioning rod 3 in a penetrating mode in a one-to-one correspondence mode, the gears to be detected are fixed on the placing table 2 through the positioning mechanism 4, at the moment, the outer dial indicator 11 is moved, so that a detecting head of the outer dial indicator 11 is sequentially contacted with the top circular side walls of the teeth of the plurality of gears to be detected, and therefore; after the external diameter measurement operation of the gear to be measured is completed, the tooth width dial indicator 18 can be moved, so that the detecting head of the tooth width dial indicator 18 is sequentially contacted with the side walls of the plurality of gears to be measured far away from the placing table 2, and the difference value of the tooth width of the gear to be measured and the standard component is obtained. So set up for but a plurality of gear that await measuring of gear parameter quick detection utensil in this application simultaneous measurement is favorable to promoting the efficiency that detects the gear.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. The utility model provides a utensil is examined fast to gear parameter which characterized in that: the automatic positioning device comprises an operating platform (1), wherein a placing platform (2) is fixedly arranged on the side wall of the operating platform (1), a plurality of positioning rods (3) are fixedly arranged on the side wall, away from the operating platform (1), of the placing platform (2), one end, close to the operating platform (1), of each positioning rod (3) is provided with a positioning mechanism (4), the side wall of the operating platform (1) is provided with an outer dial indicator (11) in a sliding mode at a position close to the placing platform (2), and the side wall of the operating platform (1) is provided with a tooth width dial indicator (18) in a sliding mode at a position relative to the outer dial indicator (11).

2. The gear parameter rapid gauge according to claim 1, characterized in that: the positioning mechanism (4) comprises a plurality of fixing columns (42) and a plurality of abutting columns (41), the fixing columns (42) are fixedly arranged on the peripheral side wall of the positioning rod (3), the abutting columns (41) are slidably sleeved on the fixing columns (42), first elastic pieces (5) are arranged in the abutting columns (41), one ends of the first elastic pieces (5) abut against the side wall of the positioning rod (3), and one ends, far away from the positioning rod (3), of the first elastic pieces (5) are fixedly arranged on the inner side wall, close to the positioning rod (3), of the abutting columns (41).

3. The gear parameter rapid gauge according to claim 2, wherein: an elastic cushion layer (6) is fixedly arranged on the side wall of the abutting column (41) far away from the positioning rod (3).

4. The gear parameter rapid gauge according to claim 1, characterized in that: the operation panel (1) is provided with spout (9) in the both sides of placing platform (2), it is provided with first slider (10) to slide in spout (9), external dial indicator (11) slide and wear to establish in first slider (10), the detecting head of external dial indicator (11) sets up towards locating lever (3) place direction, keeps away from it is provided with second slider (15) to slide in spout (9) of first slider (10), is provided with supporting shoe (17) on the lateral wall that operation panel (1) was kept away from in second slider (15), tooth width dial indicator (18) are worn to establish in supporting shoe (17), the detecting head of tooth width dial indicator (18) is towards placing platform (2) place direction setting.

5. The gear parameter rapid gauge according to claim 4, wherein: the side wall, far away from the operating table (1), of the second sliding block (15) is fixedly provided with a sliding column (16), the supporting block (17) is arranged on the sliding column (16) in a penetrating mode in a sliding mode, and a fastening piece (19) used for fixing the supporting block (17) is arranged on the side wall of the supporting block (17) in a penetrating mode.

6. The gear parameter rapid gauge according to claim 4, wherein: be provided with standing groove (12) on the lateral wall that locating lever (3) were kept away from in first slider (10), outside micrometer (11) slide and wear to establish in standing groove (12), the cover is equipped with second elastic component (13) on outside micrometer (11), one end that second elastic component (13) are close to the reference column and the end lateral wall fixed connection of standing groove (12), spacing piece (14) are fixed wearing to be equipped with in the position department of keeping away from locating lever (3) in the side wall of outside micrometer (11), the one end and spacing piece (14) butt setting that locating lever (3) were kept away from in second elastic component (13).

7. The gear parameter rapid gauge according to claim 2, wherein: and the circumferential side wall of the abutting column (41) is fixedly provided with a shifting sheet (7).

8. The gear parameter rapid gauge according to claim 1, characterized in that: the placing table (2) is fixedly provided with a flexible cushion layer (8) on the peripheral side of the positioning rod (3).