TW201740026A - Screw - Google Patents

Abstract

The present invention relates to a screw including a shank, a first thread, and a second thread. The shank includes a tapered screwing portion, a head portion, and a straight portion between the screwing portion and the head portion. The first thread is spirally formed on the shank and includes an upper thread portion formed on an outer circumference of the straight portion and a lower thread portion formed on an outer circumference of the screwing portion. The second thread is spirally formed on the shank and extends to a lower end of the straight portion from the screwing portion. The second thread includes a plurality of thread convolutions spaced from the thread convolutions of the lower thread portion of the first thread. The screw allows rapid insertion of the screw into articles to be fastened without reducing the binding force between the screw and the articles.

Description

Screw

The invention relates to a screw, in particular to a screw with a fast screwing speed and a labor-saving operation.

On wood objects including furniture, decoration and construction, wood is used in large quantities or composite wood made of plastic resin and wood chips. The connection between wooden objects is usually locked by screws. Conventional screws generally include a rod and a thread wound around the rod, which are screwed into the two objects so that the two objects can be screwed together. However, the thread of the conventional screw may come into contact with the object during the process of screwing the object to generate a considerable frictional resistance, which is laborious and time consuming to operate. Moreover, the waste generated by the thread cutting object can not be smoothly discharged, so that the screw is hindered by the waste debris during the process of screwing the object, which causes the screwing speed to be slow, the operation is laborious, and the object is liable to be cracked due to the pressing.

Accordingly, the main object of the present invention is to provide a screw which can be smoothly screwed into an object such as wood, which has a high screwing speed and is labor-saving, and further, the screw is generated in the process of screwing in the object. Chips can be smoothly removed to reduce frictional resistance.

The screw of the present invention comprises a rod body, a first thread, and a second thread. The shaft includes a tapered screw-in portion, a head portion, and a straight stem portion positioned between the screw-in portion and the head portion, the screw-in portion being spaced from the head portion on a longitudinal axis of the shaft body. The first thread is spirally wound around the outer periphery of the rod body and includes an upper thread portion and a lower thread portion. The upper thread portion is disposed at an outer circumference of the straight rod portion, and the lower thread portion is disposed at the rotation The outer periphery of the entry portion, and the bottom end of the lower threaded portion extends to the tip end of the screw-in portion to form an anchor point. The second thread is spirally disposed around the outside of the rod and extends from the screwing portion of the rod to the bottom end of the straight rod portion. The second thread includes a plurality of threads, and the thread of the second thread is The threads of the threaded portion of the first thread are spaced apart from each other, and the pitch between the adjacent two threads of the second thread is approximately equal to the pitch of the threaded portion.

In an embodiment, the straight portion includes a lower portion adjacent to the screwing portion and an upper portion adjacent to the head portion, the outer diameter of the upper portion is slightly larger than an outer diameter of the lower portion, and the first thread further includes an intermediate thread portion. The upper threaded portion is disposed around the outer circumference of the upper portion of the straight rod portion, and the intermediate thread portion is disposed around the outer circumference of the lower portion of the straight rod portion and is connected between the upper thread portion and the lower thread portion, and the thread of the upper thread portion The outer diameter is larger than the outer diameter of the thread of the intermediate thread portion. The upper thread portion and the intermediate thread portion individually include a plurality of asymmetrical threads having a thread angle of between 35 and 45 degrees and a thread angle of the intermediate thread portion being between 53 and 57 degrees.

Preferably, the threaded portion of the lower threaded portion is inclined between 55 and 65 degrees with respect to the longitudinal axis and greater than the threaded slope of the upper threaded portion relative to the longitudinal axis. The pitch of the thread of the second thread relative to the longitudinal axis is approximately equal to the pitch of the thread of the lower threaded portion.

Other objects, advantages and features of the present invention will become apparent from

The preferred embodiments of the present invention will now be described by way of example only, and not by way of limitation,

Referring to Figures 1 through 7, there is shown a screw 10 constructed in accordance with an embodiment of the present invention. The screw 10 includes a shaft 12 that includes a screw-in portion 14, a head portion 16, and a screw-in portion 14 and a head. The shank 18 is always between the portions 16. The screw-in portion 14 is separated from the head portion 16 by a longitudinal axis (X) of the shaft 12. The screwing portion 14 has a tapered shape with an angle (A) between 20 and 30 degrees (see Fig. 7), preferably 25 degrees. The straight stem portion 18 includes a lower section 20 adjacent the screw-in portion 14 and an upper section 22 adjacent the head portion 16. In the present embodiment, the outer diameter (D1) of the upper section 22 is slightly larger than the outer diameter (D2) of the lower section 20. The outer diameter of the head 16 is larger than the diameter of the shaft 12 and the upper surface of the head 16 has a bore 24 for providing insertion of a driver (not shown).

The screw 10 further includes a first thread 26, and the first thread 26 is spirally disposed on the shaft 12. In the present embodiment, the first thread 26 includes an upper threaded portion 28, a lower threaded portion 30, and an intermediate threaded portion 32. The upper threaded portion 28 is disposed around the outer portion of the upper portion 22 of the straight rod portion 18, and the lower threaded portion 30 is provided. Around the outer periphery of the screwing portion 14 of the rod body 12, the intermediate thread portion 32 is provided around the outer periphery of the lower portion 20 of the straight rod portion 18 and is connected between the upper thread portion 28 and the lower thread portion 30 such that the upper thread portion 28 and the lower thread portion The intermediate thread portion 32 and the intermediate thread portion 32 constitute a continuous first thread 26, and the bottom end of the lower thread portion 30 extends to the tip end of the screwing portion 14 to form a cutting point 34. Furthermore, the thread taper of the lower threaded portion 30 relative to the longitudinal axis (X) is greater than the thread pitch of the upper threaded portion 28 relative to the longitudinal axis (X), ie the thread of the lower threaded portion 30 has a position to be screwed in. On the side (i.e., facing the lower end of the screw-in portion 14), a cutting surface 36 (see Fig. 4), the slope (A1) of the cutting surface 36 relative to the longitudinal axis (X) is preferably 60 ± 5 degrees, i.e., at 55-65 degrees. between.

As shown in FIG. 3, the first thread portion of the upper thread portion 28 has a first pitch (P1), and the second thread portion of the lower thread portion 30 has a second pitch (P2). The pitch (P2) is slightly larger than the first pitch (P1). Furthermore, as shown in FIG. 6, the upper thread portion 28 and the intermediate thread portion 32 individually include a plurality of asymmetrical threads, wherein the thread angle (A2) of the upper thread portion 28 is 40 ± 5 degrees, that is, at 35-45 degrees. The thread angle (A3) of the intermediate thread portion 32 is 55 ± 2 degrees, that is, between 53 and 57 degrees, and further, the thread outer diameter (T1) of the upper thread portion 28 is slightly larger than that of the intermediate thread portion 32. The outer diameter of the thread (T2). Further, a cutting tooth 38 is provided on the thread of the intermediate thread portion 32 adjacent to the screwing portion 14, and the cutting tooth 38 has a zigzag shape and has an inclined helix angle to increase the cutting force of the first thread 26.

The screw 10 further includes a second thread 40 that is helically disposed about the outer periphery of the shaft 12 and that extends from the screw-in portion 14 of the shaft 12 to the bottom end of the lower section 20 of the straight portion 18. The second thread 40 includes a plurality of threads 41. The threads 41 of the second thread 40 are spaced apart from the threads of the lower thread portion 30, and the pitch between the adjacent two threads 41 and the pitch of the lower thread portion 30 (P2) Further, the inclination of the thread 41 relative to the longitudinal axis (X) is approximately equal to the thread inclination (A1) of the lower thread portion 30, as shown in FIG. In the present embodiment, the bottom end of the second thread 40 does not extend to the tip end of the screwing portion 14, and thus the tip end of the screwing portion 14 of the rod body 12 has only one cutting point 34.

The screw 10 further includes a plurality of oblique ribs 42 and at least one swarf groove 44. The rib 42 is disposed around the outer periphery of the rod body 12. In the embodiment, the rib 42 is disposed on the bottom of the tooth between the lower thread portion 30 and the adjacent two thread of the intermediate thread portion 32 for improving the chip evacuation function, and The height of the rib 42 protruding from the bottom of the tooth is smaller than the height of the first thread 26. The chip flutes 44 are provided in the lower section 20 of the straight rod portion 18 and adjacent to the screwing portion 14 for accommodating waste. A cutting surface 46 is formed on both sides of the fluffing groove 44 so that the fluffing groove 44 has an auxiliary cutting action.

The screw 10 of the present invention is implemented by inserting a cutting point 34 at the lower end of the screwing portion 14 into an article such as a wooden board, and then using the lower thread portion 30 and the second thread of the first thread 26 of the screwing portion 14 of the screw 10. 40 screw into the object. When the first thread 26 and the second thread 40 are simultaneously screwed into the object, the object is cut to generate waste, and the waste is guided by the oblique rib 42 to be upwardly removed to reduce the resistance of the screw 10 in the locking direction. The screwing speed is increased; then, when the intermediate thread portion 32 of the straight rod portion 18 is screwed into the article, the cutting teeth 40 on the intermediate thread portion 32 assist in cutting the object, making operation less laborious. Further, the scraps extruded by the ribs 42 can be accommodated in the swarf groove 44 and the inter-space of the intermediate thread portion 32 of the first thread 26 so that the waste does not accumulate in the upper section 22 of the straight portion 18. Thus, the upper section 22 of the screw 10 can be smoothly introduced into the article so that the object to be screwed does not break.

The screw 10 of the present invention has the following advantages: 1. The screwing portion 14 is provided with double threads (the lower thread portion 30 and the second thread 40 of the first thread 26) and a cutting positioning point 34, and the threaded portion of the lower thread portion 30 is inclined. The degree is greater than the pitch of the thread of the upper threaded portion 28, so that the screwing speed of the screw 10 can be effectively increased. 2. The thread angle (A3) of the intermediate thread portion 32 is larger than the thread angle (A2) of the upper thread portion 28, and the cutting teeth 38 are provided on the threads of the partial intermediate thread portion 32, which can effectively improve the screw 10 Cutting force. 3. The outer diameter (T1) of the thread of the upper thread portion 28 is slightly larger than the outer diameter (T2) of the thread of the intermediate thread portion 32, so that the crest of the upper thread portion 28 can generate a high-strength biting force for objects such as wood. Achieve the effect of increasing the bonding strength. 4. The waste generated by the cutting object can be guided through the rib 42 and discharged from the chip flute 44 and the bottom of the intermediate thread portion 32 to reduce the resistance in the locking direction, so that the operation of the screw 10 is more labor-saving.

The above description of the preferred embodiments of the present invention is not intended to limit the scope of the present invention, and the scope of the invention should be limited to the following claims. And the approximate structure should be included in the present invention.

10‧‧‧ screws
12‧‧‧ rod body
14‧‧‧Driving Department
16‧‧‧ head
18‧‧‧ Straight section
20‧‧‧ lower section
22‧‧‧上段
24‧‧‧ hole
26‧‧‧First thread
28‧‧‧Threaded Department
30‧‧‧Under threading
32‧‧‧Intermediate thread
34‧‧‧Location points
36‧‧‧cutting surface
38‧‧‧ cutting teeth
40‧‧‧second thread
41‧‧‧ threaded teeth
42‧‧‧ ribs
44‧‧‧Setting trough
46‧‧‧cutting surface

1 is a perspective view of a screw according to an embodiment of the present invention. Figure 2 shows a front view of the screw of Figure 1. Figure 3 shows a longitudinal cross-sectional view of the screw of Figure 1. Figure 4 shows a partial enlarged view of the screw of Figure 1. Figure 5 is a cross-sectional view taken along line 5-5 of Figure 2. Figure 6 shows a partial enlarged view of the screw of Figure 2. Figure 7 shows a longitudinal cross-sectional view of the screw of Figure 4.

10‧‧‧ screws

12‧‧‧ rod body

14‧‧‧Driving Department

16‧‧‧ head

18‧‧‧ Straight section

20‧‧‧ lower section

22‧‧‧上段

26‧‧‧First thread

28‧‧‧Threaded Department

30‧‧‧Under threading

32‧‧‧Intermediate thread

38‧‧‧ cutting teeth

40‧‧‧second thread

41‧‧‧ threaded teeth

42‧‧‧ ribs

44‧‧‧Setting trough

46‧‧‧cutting surface

Claims (9)

A screw comprising: a rod body including a tapered screwing portion, a head portion, and a straight rod portion between the screwing portion and the head portion, the screwing portion and the head portion of the rod body Separating a longitudinal axis; a first thread spirally wound around the outer periphery of the rod body and including an upper thread portion and a lower thread portion, the upper thread portion being disposed around the outer portion of the straight rod portion, a lower threaded portion is disposed at an outer periphery of the screwing portion, and a bottom end of the lower threaded portion extends to a tip end of the screwing portion to form a positioning point; and a second thread is spirally disposed around the rod body And extending from the screwing portion of the rod body to the bottom end of the straight rod portion, the second thread includes a plurality of threaded teeth, and the thread of the second thread is spaced apart from the thread of the thread portion of the first thread. And the pitch between the adjacent two threads of the second thread is about equal to the pitch of the lower thread portion. The screw according to claim 1, wherein the straight portion includes a lower portion adjacent to the screwing portion and an upper portion adjacent to the head portion, and an outer diameter of the upper portion is slightly larger than an outer diameter of the lower portion, the first thread further comprising a An intermediate threaded portion is disposed around an outer circumference of the upper portion of the straight rod portion, the intermediate threaded portion is disposed around an outer circumference of the lower portion of the straight rod portion and is coupled between the upper threaded portion and the lower threaded portion, the upper threaded portion The thread outer diameter of the threaded portion is larger than the outer diameter of the thread of the intermediate thread portion. The screw according to the second aspect of the patent application, wherein the upper thread portion and the intermediate thread portion individually comprise a plurality of asymmetrical thread teeth having a thread angle of 35-45 degrees, the screw of the intermediate thread portion The tooth angle is between 53-57 degrees. A screw according to claim 2, wherein the cutting teeth are provided on the thread of the intermediate thread portion adjacent to the screwing portion. According to the screw of the second aspect of the patent application, the plurality of oblique ribs are further disposed on the bottom of the tooth between the lower thread portion and the adjacent two thread of the intermediate thread portion. The screw according to Item 2 of the patent application further includes at least one chip collecting groove, and the at least one chip collecting groove is disposed at a lower portion of the straight rod portion and adjacent to the screwing portion. A screw according to the first aspect of the invention, wherein the bottom end of the second thread does not extend to the tip end of the screwing portion of the rod. A screw according to the first aspect of the invention, wherein the lower thread portion has a thread inclination of between 55 and 65 degrees with respect to the longitudinal axis and is greater than a thread inclination of the upper thread portion with respect to the longitudinal axis. A screw according to the eighth aspect of the invention, wherein the thread of the second thread has a slope with respect to the longitudinal axis that is approximately equal to a thread of the threaded portion.