CN2412756Y

CN2412756Y - Anti-skid chalk compasses

Info

Publication number: CN2412756Y
Application number: CN 99245186
Authority: CN
Inventors: 王忠华
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-10-28
Filing date: 1999-10-28
Publication date: 2001-01-03
Anticipated expiration: 2009-10-28

Abstract

The utility model relates to a pair of chalk compasses, which is convenient for drawing a circle on a hard blackboard. The utility model has the advantage that a centering needle (6) is used for centering. The stabilization of the centering needle (6) is maintained by a rubber magnetic chuck (5) to make a needle tip of the centering needle not go so far as to slide. An auxiliary rod (10) is connected with a main rod (2) by a connecting piece (7), and the auxiliary rod (10) is movably connected with the connecting piece (7) by (8) and (9). The (9) is loosened, the auxiliary rod (10) can be rotated left or right around the (8) and can be moved upward and downward following the (8) in a long gap of the connecting piece (7), distance between a chalk head and the needle point of the centering needle (6) can be regulated thus, and the distance is the same to the radius of the drawn circle. (1) is held by the left hand and downward pressed, the centering needle (6) is correspondingly moved upward to compress (4), (2) and (3) to move downward, the rubber magnetic chuck (5) is adsorbed on the blackboard, and the centering needle (6) does not slide. The connecting piece (7) is kneaded by the right hand to make the auxiliary rod (10) rotated for 360 DEG following the connecting piece (7) around the main rod (2), and then a circle is drawn.

Description

Anti-gliding style chalk compasses

The utility model relates to a kind of when hard blackboard upper drawing circle, the chalk compasses of unlikely slip.

Still at the traditional chalk compasses that use, very convenient at present at wooden blackboard upper drawing circle.And since the seventies in 20th century, wooden blackboard is replaced by class hard blackboards such as plastics, building stones, metals gradually.On the hard blackboard, it is just very inconvenient to use traditional chalk compasses to draw circle." confront the tough with toughnees " because be used for determining the metal centering needle point in the center of circle, slide easily, be difficult to the circle of the standard that is drawn as.

The purpose of this utility model, provide a kind of can be when hard blackboard upper drawing circle, the chalk compasses of unlikely slip.Also can be easily at wooden blackboard upper drawing circle.

The utility model is the sucked type educational compasses of " CN2089876U " than the notification number on Dec 4th, 1991, seems advanced.The centre point of the sucker 13 of these compasses can not place on the blackboard on the known point as the center of circle exactly.When leg 11 with the angle of cut of blackboard surface during less than 60 °, the outside of soft limit skirt 2 will have been lifted up, and causes 13 can not be stabilized in circle centre position, and can not finish the task of what a circle of picture.

The purpose of this utility model is achieved in that

1. chalk is put into (11), make (12) the chalk banding.Left hand is held (1), puts tip known circle centre position on blackboard of (6).Loosening (9) are regulated (8) position the space in (7), and (10) are rotated to the left or to the right, the needle point of definite (6) and the distance of chalk head, make it equal ask and make radius of a circle, (9) are tightened.

2. left hand makes (2) perpendicular to blackboard surface, and firmly to pressing down, (6) move up relatively and compress (4), and (2) and (3) move down simultaneously, (5) also move down with (3), and push down blackboard, the air inner because of (5) is discharged from major part, so its air pressure inside is lower than atmospheric pressure, because the effect of draught head, make (5) be adsorbed on the blackboard tightly, and safeguard that (6) are stabilized in circle centre position, unlikely slip.

3. the right hand pinches (7), make (10) with (7) around (2) rotation 360 ° or less than 360 °, then the drawn track of chalk head is the circle or the circular arc of the work of asking.

4. left hand firmly pulls out (2), makes (5) break away from blackboard and reinstatement.(4) resilience and drive (6) to original position.

If changing chalk into fluid injection has coloured pencil, then can be at the blank upper drawing circle.

Below in conjunction with accompanying drawing, the technical program is described further.Accompanying drawing is integrally-built front view, and institute's target number 1～12 is the sequence number of whole parts among the figure.Handle (1) and mobile jib (2) are connect by screw threads for fastening.Mobile jib (2) and secondary bar (10) are the trunk parts.Mobile jib (2) and spring box (3) are connect by screw threads for fastening.Rubber suction cups (5) is enclosed within the bottom of (3), and centering pin (6) is in the central authorities of (3), and compression spring (4) is enclosed within the periphery of (6), and an annulus is protruded at the middle part of (6), and it blocks (4).Plate (7) and (10) are by screw (8) link joint, and regulate its degree of tightness by fish bolt nut (9).Chalk folder (11) securely is enclosed within the lower end of (10).(7) being enclosed within the upper end of (2), movingly, being pushed down by (1), but do not kill, can serve as the axle rotation with (2).One microscler space is arranged at bottom (7), and the width in space equals the diameter of (8), and (10) can rotate around (8) in the space to the left or to the right, and moves with (8) are upper and lower, and plastics hoop (12) can make (11) to clamp chalk.

Claims

1. anti-gliding style chalk compasses.The technical characterictic of traditional chalk compasses is to be made of two timber pin, and wherein the lower end centering pin of a leg is that metal material makes.Technical characterictic of the present utility model is to be made of mobile jib and supplement.Parts of client link under the mobile jib; Client link a plate on the secondary bar.

2. compasses according to claim 1 is characterized in that securely connecting parts by the external thread of mobile jib lower end and the internal thread of spring box.These parts are assembled by spring box, compression spring, rubber suction cups and centering pin.

3. by the described compasses of claim 1, it is characterized in that secondary bar by screw and fish bolt nut and plate connection, has a microscler space in the plate.