CN203818849U

CN203818849U - Compasses

Info

Publication number: CN203818849U
Application number: CN201420104163.XU
Authority: CN
Inventors: 于立艳; 孙海涛; 林志良
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-03-07
Filing date: 2014-03-07
Publication date: 2014-09-10
Anticipated expiration: 2024-03-07

Abstract

The utility model relates to a pair of compasses, which comprises a drawing stand bar and a positioning stand bar, wherein the end part of one end of the drawing stand bar is hinged to the end part of one end of the positioning stand bar, and the end part of the other end of the drawing stand bar is provided with a pen cap. The compasses are characterized in that the drawing stand bar is fixedly provided with a flexible rule capable of automatically retracting a rule tape; a through cavity suitable for the rule tape to pass through is also formed at a position, near the tip of the drawing stand bar, on the drawing stand bar; a transparent reading window is formed in the side wall of the through cavity; the starting end of the rule tape of the flexible rule passes through the through cavity, and is connected onto the positioning stand bar. The compasses provided by the utility model are simple and compact in structure, convenient to read and small in error.

Description

Compasses

Technical field

The utility model relates to a kind of teaching drawing apparatus, is specifically related to a kind of compasses.

Background technology

Compasses, in mathematics and drawing, are for the instrument of draw circles or string, are usually used in construction with ruler and compasses.

Compasses of the prior art are being drawn the bowlder of predetermined diameter processed or radius, break two legs of compasses into two with one's hands certain amplitude often, then contrast and adjust with scale on ruler, use very inconvenient, not only must carry ruler, and two hand operateds very trouble of getting up also, the most important thing is drawn radius of a circle or directly easily occur error.

Chinese patent literature CN201792647U discloses a kind of compasses with graduated scale, these compasses comprise drawing leg and location leg, the end of the end of described drawing leg and described location leg is hinged, the free end of described drawing leg is provided with the pen cap, the free end of described location leg is provided with sucker, the centre position of described location leg is hinged with the graduated scale that can rotate around the mid point of described location leg, and the centre position of described drawing leg is provided with graduation indication pin.

On compasses in this patent documentation, carry graduation indication pin, without a hand, break compasses into two with one's hands, another hand is taken ruler, use more convenient, but in use also there is following shortcoming: 1, graduated scale is arranged on the centre position of compasses leg, drawn radius of a circle must be multiplied by two for the numerical value of indicating on graduated scale, reading is inconvenient, not direct, and because arranging of centre position can exist error, can there is slight error in reading itself, after being multiplied by two, error will increase, therefore, the circular error that compasses draw in this patent documentation can be larger, 2, rule directly can be rotatably set on compasses leg, make the structure of compasses look complicated, and outside the scale on rule is at every moment exposed to, be easily worn and thicken, more importantly, rule is easily suspended to or touches other things.

Utility model content

For this reason, technical problem to be solved in the utility model is compasses complex structure of the prior art, and reading trouble and the larger problem of error, provide a kind of simple and compact for structure, the compasses that convenient reading and error are little.

For solving the problems of the technologies described above, a kind of compasses of the present utility model, comprise drawing leg and location leg, the end of the end of described drawing leg one end and leg one end, described location is hinged, and the other end end of described drawing leg is provided with the pen cap, it is characterized in that: on described drawing leg, being installed with can be by the tape measure of chi band automatic drawing back, the close drawing leg tiptoe place of described drawing leg also forms and is applicable to the cavity that described chi band passes, one sidewall of described cavity is provided with transparent reading window, the initiating terminal of the described chi band of described tape measure is through described cavity, be connected on the leg of described location.

Described tape measure is also provided with the locking device on the housing of described tape measure by described chi locking.

Scale on described chi band is along the following setting of described chi band.

The described pen cap is made as from moving the core pen cap.

Described reading window is visual glass windows mouth.

Technique scheme of the present utility model has the following advantages compared to existing technology:

1, in the utility model; on drawing leg, being installed with can be by the tape measure of chi band automatic drawing back; the close drawing leg tiptoe place of drawing leg also forms and is applicable to the cavity that described chi band passes; one sidewall of cavity is provided with transparent reading window; the initiating terminal of the chi band of tape measure is through described cavity; be connected on the leg of location; such structure is arranged so that compasses of the present utility model not only can facilitate reading; error is little; and when not using; chi band is recoverable in the housing of the tape measure 4 on drawing leg 1, and chi band is protected.

2, in the utility model, tape measure is also provided with the locking device on the housing of tape measure by chi locking, and the length that can stretch out chi band locks, and compasses of the present utility model is used more convenient.

Accompanying drawing explanation

For content of the present utility model is more likely to be clearly understood, according to specific embodiment of the utility model also by reference to the accompanying drawings, the utility model is described in further detail, wherein below

Use state diagram when Fig. 1 is compasses drawing of the present utility model;

Schematic diagram after Fig. 2 compasses of the present utility model draw in;

In figure, Reference numeral is expressed as: 1-drawing leg, 2-location leg, the 3-pen cap, 4-tape measure, 5-chi band, 6-reading window, 7-locking device.

The specific embodiment

As shown in Figure 1-2, compasses in the present embodiment, comprise drawing leg 1 and location leg 2, the end of the end of described drawing leg 1 one end and leg 2 one end, described location is hinged, and the other end end of described drawing leg 1 is provided with the pen cap 3, on described drawing leg 1, being installed with can be by the tape measure 4 of chi band 5 automatic drawing backs, the close drawing leg 1 tiptoe place of described drawing leg 1 also forms and is applicable to the cavity that described chi band 5 passes, one sidewall of described cavity is provided with transparent reading window 6, the initiating terminal of the described chi band 5 of described tape measure 4 is through described cavity, be connected on described location leg 2.The compasses of the present utility model that are arranged so that of said structure not only can facilitate reading, and error is little, and when not using, chi band is recoverable in the housing of the tape measure 4 on drawing leg 1, and chi band is protected.

For the length that chi band 5 is stretched out locks, compasses of the present utility model are used more convenient, described tape measure 4 is also provided with described chi band 5 is locked in to the locking device 7 on the housing of described tape measure 4.

Scale on described chi band 5 is along the following setting of described chi band 5, and the scale numerical value on described chi band 5 can arrange upward, also can arrange down, as shown in Figure 1.

In order to be convenient for changing pen core, the described pen cap 3 is made as from moving the core pen cap.

Described reading window 6 is visual glass windows mouth, can certainly be transparent plastic paper.

The measuring process of compasses of the present utility model:

Outwards move drawing leg 1 and location leg 2, observe the reading window 6 on drawing leg 1, when the nib on the pen cap 3 aligns with the preliminary election scale value on chi band 5, press locking device, by 5 lockings of chi band, now chi band 5 length are locked, as shown in Figure 1, and then compasses using method routinely mapping.

After mapping, the locking of device to chi band 5 that unlock, inwardly moves drawing leg 1 and location leg 2, makes the two gather merging.Under the effect of the torsion spring of chi band 5 in tape measure in the housing of automatic drawing back tape measure, as shown in Figure 2.

Obviously, above-described embodiment is only for example is clearly described, not the restriction to embodiment.For those of ordinary skill in the field, can also make other changes in different forms on the basis of the above description.Here exhaustive without also giving all embodiments.And among the protection domain that the apparent variation of being extended out thus or change are still created in the utility model.

Claims

1. compasses, comprise drawing leg (1) and location leg (2), the end of the end of described drawing leg (1) one end and described location leg (2) one end is hinged, and the other end end of described drawing leg (1) is provided with the pen cap (3), it is characterized in that: on described drawing leg (1), being installed with can be by the tape measure (4) of chi band (5) automatic drawing back, close drawing leg (1) the tiptoe place of described drawing leg (1) also forms and is applicable to the cavity that described chi band (5) passes, one sidewall of described cavity is provided with transparent reading window (6), the initiating terminal of the described chi band (5) of described tape measure (4) is through described cavity, be connected on described location leg (2).

2. compasses according to claim 1, is characterized in that: described tape measure (4) is also provided with described chi band (5) is locked in to the locking device (7) on the housing of described tape measure (4).

3. compasses according to claim 1 and 2, is characterized in that: the scale on described chi band (5) is along the following setting of described chi band (5).

4. compasses according to claim 1, is characterized in that: the described pen cap (3) is made as from moving the core pen cap.

5. compasses according to claim 1, is characterized in that: described reading window (6) is visual glass windows mouth.