A kind of on-deformable tape measure wheel hub
Technical field
The present invention relates to a kind of collecting device of tape measure, particularly relate to a kind of on-deformable tape measure wheel hub.
Background technology
Tape measure is little because of volume, and is easy to carry, become one of the instrument of staff's indispensability of a lot of industries as a kind of survey instrument that is easy to carry about with one.
Existing tape measure generally comprises chi box, wheel hub and is wound on chi band on the wheel hub, and wherein, wheel hub is the collecting device of tape measure, can bounce back automatically under the wind spring restoring force effect of chi band in being built in wheel hub.Usually, wheel hub has wheel hub cover and hub seat to constitute, in the processing and manufacturing process, wind spring need be put into the cavity of hub seat in advance, is fixed in the hub seat by fastening wheel hub cover again, therefore, generally all the spacer of withholding wheel hub cover can be arranged on the edge of hub seat, this spacer can pass the perforation that correspondingly is arranged on the wheel hub cover, make wheel hub cover closely and hub seat withhold mutually, also promptly, this structure provides the axial limiting between wheel hub cover and the hub seat.But, in actual production, can find, when tape measure is longer, required wind spring backrush pretightning force is also bigger, so the width of wind spring and length are all bigger, in use for some time, the radial deformation distortion takes place in wheel hub easily under the tension force effect of wind spring, use thereby influence is normal, also shortened the serviceable life of caliper scale, need further this to be improved.
Summary of the invention
Technical matters to be solved by this invention is the tape measure wheel hub that a kind of difficult generation radial distorted distortion is provided at above-mentioned prior art present situation.
The present invention solves the problems of the technologies described above the technical scheme that is adopted: this on-deformable tape measure wheel hub, comprise hub seat and wheel hub cover, wherein hub seat include disk and be connected as a single entity with it, and vertical with it cylinder sheet, described wheel hub cover then is fastened on the end of this cylinder sheet, it is characterized in that also being provided with at least two axial projection portions, then correspondingly have at wheel hub cover and can hold this axial projection portion inserting aperture wherein at the end of described cylinder sheet.
Consider the good stability of triangle location, and can make wheel hub cover cooperate with hub seat that afterwards radial force is even, described axial projection portion is three, and circumferentially uniform along the cylinder sheet.
In order to guarantee to take turns the axial limiting between wheel hub cover and the hub seat, described wheel hub cover can be fastened on the end of this cylinder sheet in the following manner: the cylinder sheet of hub seat is provided with the catch of axial evagination at its end, protuberance in this catch end has radially, on the wheel hub cover then the position in correspondence have spacing hole, catch passes spacing hole, and the radially interior protuberance clinching of catch is on wheel hub cover.
Evenly described catch is three for the stability of locating and hub seat cylinder sheet end and wheel hub cover stressed, and circumferentially uniform along the cylinder sheet.
Axial projection on the described wheel hub cover preferably can be arranged on the position near catch, and promptly described axial projection portion and described catch are contiguous mutually to be provided with.
Compared with prior art, the invention has the advantages that: set up lug boss by cylinder sheet end at hub seat, make original tape measure wheel hub on the basis that prevents hub seat and wheel hub cover axial separation, increased barrier force radially again, thereby when wheel hub is subjected to bigger wind spring tension force, can prevent the radial distorted distortion of wheel hub effectively, prolong the serviceable life of wheel hub.
Description of drawings
Fig. 1 is the spatial structure exploded view of the embodiment of the invention.
Fig. 2 is the vertical view of the embodiment of the invention.
Fig. 3 is that A-A shown in Figure 2 is to cut-open view.
Fig. 4 is the side view of the embodiment of the invention.
Embodiment
Embodiment describes in further detail the present invention below in conjunction with accompanying drawing.
As Fig. 1~shown in Figure 4, a kind of on-deformable tape measure wheel hub comprises a hub seat 1 and a wheel hub cover 2 that is provided with center pit accordingly with central shaft hole, wherein hub seat 1 includes disk 11 and is connected as a single entity with it, and vertical with it cylinder sheet 12, described wheel hub cover 2 is fastened on the end of this cylinder sheet 12 in the following manner: the cylinder sheet 12 of hub seat 1 is provided with three axial evaginations at its end, and along the circumferential uniform catch 13 of cylinder sheet 12,14,15, protuberance in the end of this catch also has radially, then have spacing hole 21 on the wheel hub cover 2 in the position of correspondence, 22,23, catch 13,14,15 pass corresponding spacing hole 21,22,23 and by correspondence radially in the protuberance clinching on wheel hub cover 2.
End at described cylinder sheet 12 also is provided with three circumferential uniform axial projection portions 16,17,18 along cylinder sheet 12, then correspondingly have at wheel hub cover 2 and can hold these axial projection portion 16,17,18 insertings three apertures 24,25,26 wherein, described axial projection portion 16,17,18 and contiguous be provided with corresponding mutually respectively with catch 13,14,15.
In order to guarantee being connected of tape measure and wind spring, the wind spring interface that prevents to pack in the wheel hub can not be fully retracted in the hub seat cavity, the irregular breach 121 that also has a band V-type screens a of portion on the cylinder sheet 12 of hub seat 1, wheel hub cover 2 then has an inserted sheet 24 that extends in addition downwards at irregular breach 121 places of corresponding cylinder sheet 12, this inserted sheet 24 have one with the corresponding reverse V-shaped breach b of the described V-type screens a of portion and form a spacing hole, wind spring one end can pass in hub seat by this spacing hole, and is stuck on this spacing hole and is exposed to outside the wheel hub.