CN2447556Y

CN2447556Y - Thread-cutting wooden screw

Info

Publication number: CN2447556Y
Application number: CN 00251531
Authority: CN
Inventors: 高文俊; 蔡明雄
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-09-04
Filing date: 2000-09-04
Publication date: 2001-09-12
Anticipated expiration: 2010-09-04

Abstract

The utility model relates to a thread-cutting type wooden screw which comprises a nut head and a screw rod. The screw rod is provided with screw threads. The tooth diameters of the screw threads are divided into two sections. One section of front screw threads with smaller tooth diameters is arranged from the sharp and convex end of the screw rod, and back screw threads with larger tooth diameters are continued. Sharp and convex parts are arranged among tooth distances at the front half section of the sharp and convex end of the screw rod. At least one sharp and convex part is arranged on the annular face of a screw thread. Because the sharp and convex parts are arranged among the tooth distances of the screw threads, the utility model can cut off wooden fibers and discharges wooden chips as rotation. Users can save labor when cut harder timbers. Otherwise, the utility model is matched with the design of different tooth diameters of the front and the back screw threads, and can improve the locking force of the screw.

Description

A kind of tapping formula WOOD SCREWS

The utility model relates to a kind of screw.

Existing screw 1 (as shown in Figure 1), usually has a bigger cap head 11, this cap head is provided with a word or cross turn trough 111, screw rod 12 is then by the cap head 11 root edges small pole diameter that contracts gradually downwards, till a sharp protruding end 121, screw rod 12 be provided with by acies under the cap head to sharp protruding end 121 around thread 13, in general; In order to screw in more smoothly in the timber, the tooth footpath of its thread 13 is dwindled to sharp protruding end 121 gradually by cap head lower edge, in design, the angle of tooth peak 131 its sharp coigns of this thread, the oblique angle that is 20 degree by the prominent middle mind-set both sides of point respectively, just the tooth peak 131 of this thread is the sharp coign of symmetry, with this; When the turn screw enters in the timber, looser as the material of timber, just can screw in easily, but it is harder to run into wood quality, want the DRIVE SCREWS will be gruelling, the fiber that its thread will very powerful cut-out timber when not only screwing in, and also the tooth footpath of thread is strengthened again gradually when going deep into more, therefore by beginning to whole screw-ins, all equally to exert oneself very much, especially during DRIVE SCREWS, fully with the fiber of thread extruding timber, could screw in gradually, more increase the required turn power of DRIVE SCREWS.In addition, the tooth peak of thread is monosymmetric sharp coign, and when wood quality was softer, though be easy to screw in, its pull-out capacity was relatively poor, and is heavier or when the situation of vibration kenel was arranged, this screw just was easier to loosening or gets loose drop out as desiring set.

Can be comparatively laborsaving when the purpose of this utility model aims to provide a kind of being used, and the strong improved tapping formula WOOD SCREWS of screw locking force.

The said WOOD SCREWS of the utility model comprises cap head and screw rod, screw rod screw rod on is established thread from the cap head root edge sharp protruding end of small pole diameter to of contracting gradually downwards, and the tooth of thread directly divides two sections, establish one section less preceding thread in tooth footpath from sharp protruding end, continue again to cap head root edge and establish back thread than the molar footpath.Between the tooth distance of the extremely preceding half section thread in the sharp protruding end of screw rod, by on the half waist position at tooth peak, extending projecting part at the bottom of the tooth, this projecting part from bottom to top forms a plane of inclination, and extend the plane of inclination at a certain angle to both sides, form a sharp-pointed face, 1 projecting part is set on each anchor ring of thread at least.

Fig. 1 is the structural representation of existing screw.

Fig. 2 is the utility model structural representation.

Fig. 3～5 are the utility model user mode schematic representation.

Below in conjunction with accompanying drawing structure of the present utility model and characteristics are elaborated.

As Fig. 2, the improved screw 2 of the utility model is provided with thread in screw rod 22 to its sharp protruding end 221 of cap head 21 lower edges, and the tooth of thread directly is divided into two-part, sharp protruding end by screw rod is provided with the less preceding thread 23 in tooth footpath for 221 one section, continue again and be back thread 24 than the molar footpath, and in the middle of at the bottom of the tooth of preceding thread 23 and the several back threads 24 that continue, by 231 extending projecting part 25 at the bottom of the tooth to the half waist position at tooth peak 232, this projecting part 25 forms a plane of inclination in mode from bottom to top, and tilt at a certain angle and extend to both sides, form a sharp-pointed face 251, on the anchor ring of thread, one or more are set, in implementing, directly decide quantity according to screw rod 22 bars of screw, it is good with big bar footpath person more projecting part being set.

When desire uses this screw to screw in the timber, as shown in Figure 3, after timber is inserted in the screw rod 22 sharp protruding ends 221 of helical, after beginning is with the screwdriver turn, because the tooth of its preceding thread 23 footpath is less, so the user can require great effort very much, just can earlier screw be screwed in the timber and locate, secondly, when preceding thread 23 is threaded in the timber, be located at tooth apart between projecting part 25 will allow its sharp-pointed face 251 directly to the insertion lumber fibre in, and in turn, the fiber of the cut-out timber that the sharp-pointed face 251 of its inclination can be horizontal makes the turn of thread more laborsaving, at this moment, be subjected to projecting part 25 wood chip that blends that cuts off between this thread, as shown in Figure 4, can be along with the screw-in of preceding thread 23, discharge both sides, plane of inclination along projecting part 25, for meeting the principle that can be bonded to after screw screws in the timber, so setting up of the projecting part between its thread is unreachable in Ya Feng, half that it is only reached in the tooth peak highly is the best, then, when again screw being continued to screw in the timber, as shown in Figure 5, because of the fiber in the timber is cut off, its hole can slightly strengthen, so, utilize the tooth footpath of back thread 24 bigger, in the time of in screwing in timber, can increase its locking force.

Claims

1. tapping formula WOOD SCREWS, comprise cap head and screw rod, screw rod is from the cap head root edge sharp protruding end of small pole diameter to of contracting gradually downwards, establish thread on the screw rod, it is characterized in that the tooth of thread directly divides two sections, establish one section from sharp protruding end before thread, continue again to cap head root edge establish the back thread, the tooth footpath of back thread extends projecting part greater than preceding thread between the tooth of thread distance, and 1 projecting part is set on each anchor ring of thread at least.

2. a kind of tapping formula WOOD SCREWS as claimed in claim 1, the tooth that it is characterized in that sharp protruding end that projecting part is arranged at screw rod playing preceding half section thread apart between.

3. a kind of tapping formula WOOD SCREWS as claimed in claim 1 is characterized in that said projecting part is arranged at the bottom of the tooth of thread on the half waist position at tooth peak, from bottom to top forms a plane of inclination, and tilts and extend to both sides, forms a sharp-pointed face.

4. a kind of tapping formula WOOD SCREWS as claimed in claim 1, the height that it is characterized in that projecting part is half of tooth peak.