Novel portable compasses suitable for large area mapping
The utility model relates to drawing tool technical fields, more particularly to a kind of pocket suitable for large area mapping
Compasses are a kind of people's daily life and the essential tool that works.In existing compasses, Wo Menyou
Student's compasses and dedicated compasses of constructing, these are mostly made into two brackets and a pencil.Its shortcoming exists
1 is only used for small area drawing, and drawing larger for some areas can not play a role well；
2 compasses fulcrums be easy to cause damage to paper；
3 long-armed compasses occupied spaces are larger inconvenient to carry and are easily damaged；
4 most of compasses can only install pencil, be easy to loosen using long two-arm joining place.
Summary of the invention
In response to the deficiencies in the existing technology, the utility model provides a kind of pocket circle suitable for large area mapping
Rule, the scope of application is wider, is more suitable for large area mapping.
Novel portable compasses suitable for large area mapping, which is characterized in that including cylinder, bolt and hemispheric bottom
Seat, the pedestal center are provided with a through-hole, and the base side is provided with a threaded hole, the central axis phase of the threaded hole and through-hole
It is mutually vertical；In the cylinder insertion through-hole, bolt screws in threaded hole and cylinder and pedestal links together；
The cylinder upper surface is equipped with block-like protrusions object A, and lower end surface is opened there are four symmetrical groove A；
The column side face is provided with the arc groove that angle is 120 °, and the length of the arc groove is less than the length of cylinder；Institute
It states and is also provided with annular groove between arc groove and cylinder lower end surface, annular groove is equipped with small ring, and the profile height of the small ring does not surpass
Cross the profile height of cylinder；
The base outer surface is equipped with a block-like protrusions object B and lifting lug, and the lifting lug is connected by cord with small ring；
A groove B is also provided on the base outer surface, one end of groove B is connected with lifting lug, the other end and pedestal following table
Face is connected；
A circular groove coaxial with pedestal centre through-hole, institute are provided in the chassis interior apart from base lower surface a distance
It states circular groove and is connected by another through-hole with groove B；
The cord cross is wrapped on four symmetrical groove A, forms a protrusion in cylinder lower end surface.
The utility model has the following beneficial effects: (1) changes the protrusion after original thinking is intersected using line as branch
Point reduces the damage to paper, while improving safety without sharp component；Replace compasses long-armed with cord, so that
The circle of larger radius can be made under identical compasses volume.Each part of compasses itself includes the different circular configuration of radius
Fast and easy does figure.The via design of pedestal centre allows compasses to assemble different thicknesses pen of different shapes, use scope
Extensively.(2) through-hole of pedestal centre can be used for placing cylinder in compasses when not in use, annular groove and pedestal lower end on cylinder
The groove C in face can be used for storing cord, save parking space.
Detailed description of the invention
Fig. 1 is the structural schematic diagram of the Novel portable compasses described in the utility model suitable for large area mapping.
Fig. 2 is domed base structural schematic diagram described in the utility model.
Fig. 3 is column structure schematic diagram described in the utility model.
In figure: 1- cylinder；2- bolt；The small ring of 3- block-like protrusions object B, 4-；5- groove A；6- groove B.
As shown in Figure 1, it is suitable for the Novel portable compasses of large area mapping, including cylinder 1, bolt 2 and domed base,
The pedestal center is provided with a through-hole, and base side is provided with a threaded hole, and the central axis of the threaded hole and through-hole is mutually perpendicular to；
The cylinder 1 is inserted into through-hole, and bolt 2 screws in threaded hole and cylinder 1 links together with pedestal；
As shown in figure 3,1 upper surface of cylinder is equipped with block-like protrusions object A, lower end surface is opened there are four symmetrical groove
A5,1 side of cylinder are provided with the arc groove that angle is 120 °, and the length of the arc groove is less than the length of cylinder 1；The arc
Annular groove is also provided between 1 lower end surface of shape slot and cylinder, annular groove is equipped with small ring 4, and the profile height of the small ring 4 is no more than
The profile height of cylinder 1.
As shown in Fig. 2, the base outer surface be equipped with a block-like protrusions object B3 and lifting lug, the lifting lug by cord with
Small ring 4 is connected；A groove B6 is also provided on the base outer surface, one end of groove B6 is connected with lifting lug, the other end and pedestal
Lower surface is connected, and groove B facilitates cord cabling；One and pedestal are provided in the chassis interior apart from base lower surface a distance
The coaxial circular groove of centre through-hole, the circular groove are connected by another through-hole with groove B6；The cord cross is wrapped in
On four symmetrical groove A5, a protrusion is formed in 1 lower end surface of cylinder, which is the center of circle of drawn circle.
When compasses when not in use, ine wound follows the through-hole of the inserted base centre together of cylinder 1 on annular groove
In, bolt 2 screws in threaded hole, and cylinder 1 is fixed together with pedestal.
When using compasses, bolt 2 is rotated, cylinder 1 is taken out, if the length of cord reserved mistake when harvesting compasses
Short, cord is loosened any by rotatable cylinder 1 makes cylinder 1 be easier to take out.By putting to more longer than needed for mapping for cord
Length, and cross is wound on the symmetrical groove A5 in 1 bottom of cylinder four, cord is fixed in 1 bottom cross of cylinder
When cross section protrusion, which is the drawn center of circle justified.Pen used in drawing pours into pedestal center from base bottom
In the through-hole at place, bolt 2 screws in threaded hole and is fixed on the base pen, and domed base is inverted block-like protrusions object B3 and resists paper
Face, to ensure that paintbrush can keep stable in mapping.
In mapping, cylinder 1 is the support leg of traditional compasses, and domed base is the pen of traditional compasses, rotation half
Spherical base can draw complete circle.
Above provide the descriptions to embodiment, so that any person skilled in the art can be used or utilize this practical new
Type, rather than limitations of the present invention, person skilled in the relevant technique do not depart from the utility model spirit and
In the case where range, it can also make a variety of changes or convert, therefore all equivalent schemes also should belong to the utility model
Scope should there is each claim to limit.