CN201148073Y - Accurate compasses - Google Patents

Abstract

The utility model relates to a precise bow compass, comprising a supporting rod and a traveling rod. The supporting rod is connected with the top end of the traveling rod by a shaft, a groove is arranged on the outer flank of the middle part of the traveling rod, and a small pencil is arranged therein; the inside lower end of the supporting rod is hollow, a small curve ruler is arranged in the hollow cavity, and a clip is arranged along the brim of the hollow cavity; the end (with zero graduation) of the small curve ruler is permanently connected with the position in which the traveling rod corresponds to the hollow cavity of the supporting rod; the length of the traveling rod is smaller than the length of the supporting rod, and a round plug hole is arranged at the bottom end, the diameter is equal to the diameter of the small pencil. The user can draw out the small curve ruler and determine the length first, and then fix the clip on the supporting rod; a circle with precise radius will be drawn up by turning the traveling rod if the small pencil is inserted into the round plug socket of the traveling rod. The utility model has the advantages of simple structure, user-friendly functions, rational constitution, etc. The utility model is capable to settle the problem that precise circles can not be drawn out by the conventional bow compasses without the support of auxiliary tools.

Description

Accurate compasses

Technical field

The utility model relates to a kind of drafting instrument, especially a kind of accurate compasses of the precise radius of can drawing.

Background technology

Existing compasses need standby one rule when drawing the known radius circle, both bothered, and occupy again and have living space, and also can influence the efficient of picture.

Summary of the invention

The purpose of this utility model provides a kind of accurate compasses, is used to solve existing compasses can not drawn accurate circle under the situation of no aid problem.

For achieving the above object, the accurate compasses of the utility model comprise support bar and motion bar, and support bar is connected with motion bar top axle, offer groove in the outside, middle part of motion bar, and little pencil is placed in one; The inside lower end of support bar is a hollow structure, and little tape measure is positioned at its hollow cavity, and establishes clip at the hollow cavity edge; Rouleau chi zero graduation one end is fixed in the position of the corresponding support bar hollow cavity of motion bar; The length of motion bar is less than the length of support bar, and is provided with circular jack in its bottom, and its diameter equals the diameter of little pencil.

After adopting said structure, during use, the user can extract the rouleau chi out determine length earlier, is fixed on the support bar with clip then, little pencil is inserted in the circular socket holes of motion bar the rotary moveable bar circle of precise radius that can draw.

The utility model has the advantages that: simple in structure, easy to use, structure has rationally solved existing compasses under the situation of no aid effectively, can not draw the problem of accurate circle.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the accurate compasses of the utility model.

The specific embodiment

As shown in Figure 1, the accurate compasses of the utility model comprise support bar 1 and motion bar 2, and support bar 1 is connected with motion bar 2 top axles, offer groove in the outside, middle part of motion bar 2, and little pencil 3 is placed in one; The inside lower end of support bar 1 is a hollow structure, and rouleau chi 4 is positioned at its hollow cavity, and establishes clip 5 at the hollow cavity edge; Rouleau chi 4 zero graduations one end is fixed in the position of motion bar 2 corresponding support bar 1 hollow cavities; The length of motion bar 2 is less than the length of support bar 1, and be provided with circular jack 6 in its bottom, its diameter equals the diameter of little pencil 3, during use, the user can extract middle tape measure 4 out determine length earlier, is fixed with clip 5 then, little pencil 3 is taken out in the groove of motion bar 2, insert in the circular socket holes 6 of motion bar 2 bottoms, the rotary moveable bar 2 then, and accurate circle can draw.

Claims (2)

1, a kind of accurate compasses comprise support bar (1) and motion bar (2), it is characterized in that: support bar (1) is connected with motion bar (2) top axle, offers groove in the outside, middle part of motion bar (2), and little pencil (3) is placed in one; The inside lower end of support bar (1) is a hollow structure, and little tape measure (4) is positioned at its hollow cavity, and establishes clip (5) at the hollow cavity edge; Little tape measure (4) zero graduation one end is fixed in the position of the corresponding support bar of motion bar (2) (1) hollow cavity.

2, a kind of accurate compasses according to claim 1 is characterized in that: the length of motion bar (2) is less than the length of support bar (1), and is provided with circular jack (6) in its bottom, and its diameter equals the diameter of little pencil (3).

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