JP2003203701A - Piercing terminal connection structure - Google Patents

Abstract

(57) [Problem] To provide a connection structure of a piercing terminal which can be reduced in size and has excellent connection reliability. SOLUTION: A first penetrating blade erected from one side edge of a base portion of a piercing terminal is penetrated together with a flat conductor from one surface of a flat cable to make contact and conduct between the first penetrating blade and the flat conductor. At the same time, the first penetrating blade protruding from the other surface of the flat cable is spirally wound to form an elastic spiral portion, and the winding surface of the elastic spiral portion contacts the first penetrating blade and the flat conductor. A piercing terminal connection structure that elastically contacts the surface of the peripheral flat cable. The contact portion is pressed against the inner wall surface of the first penetrating blade by the winding surface of the elastic spiral portion so that the elastic spiral portion tends to spread outward due to the springback. A contact load can be applied, and connection reliability can be improved while reducing the size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connecting structure for piercing terminals, and more particularly, to automobiles, OA equipment,
The present invention relates to a connection structure for a piercing terminal that is suitable for connection with a flat cable used for internal wiring of home electric appliances and the like.

[0002]

2. Description of the Related Art In recent years, high performance and high functionality have been rapidly promoted mainly in automobiles, office automation equipment, home electric appliances, etc.
For example, a large number of various interior parts, wirings, etc. are used in the doors and seats of automobiles, which tends to become more complicated. Therefore, space-saving and weight-saving are required for internal wiring, etc., and in places where there is almost no gap for wiring, it is much more difficult than the conventionally used round cables. Flat cables, which are thin and have excellent flexibility, are generally used.

As shown in FIG. 11, this type of flat cable 100 is called a so-called FFC (flexible flat cable), and its structure is such that flat conductors 101 made of copper foil or the like are arranged in parallel at a predetermined interval. By being arranged and sandwiched from both sides by an insulating sheet 102 made of an insulating resin such as polyethylene terephthalate, a ribbon shape having flexibility as a whole is formed.

As a connection terminal connected to such a flat cable 100, a so-called piercing terminal 103, which is a piercing type connection terminal for piercing and connecting with the flat conductor 101 of the flat cable 100, is generally known. The piercing terminal 103 of this type has an advantage that it can be easily connected to the flat cable 100 without peeling off the insulating sheet 102 at the time of connection.

As a connection structure of the piercing terminal 103 to the flat cable 100, as shown in FIGS. 11 and 12, through blades 105a and 105b which are erected upright on both left and right sides of a base 104 of the piercing terminal 103. The flat cable 100 is arranged above the ends of the
These penetrating blades 105a, 105 in which 6b is sharply formed
b is penetrated together with the flat conductor 101 of the flat cable 100. After that, the penetrating blades 105a, 105 projected on the upper surface
b is swaged inward as shown in FIG. 13, or is once spread outward as shown in FIG.
The connection structure is such that an inward contact load or an outward contact load is applied between the 5a and 105b and the fracture surface of the flat conductor 101.

[0006]

In recent years, there is a demand for further space saving and weight reduction for wirings used especially for automobiles, etc., and accordingly, connection terminals are more Miniaturization is required. However, when the width L of the base portion 104 of the piercing terminal 103 is narrowed (narrowed pitch) to reduce the size, the connection structure of the piercing terminal cannot be applied as it is.

This is because the narrower the width L of the base portion is, the tip portion 106 of the penetrating blades 105a, 105b facing each other.
It becomes difficult to perform the crimping process in which the a and 106b are brought closer to each other inward, and a sufficient contact load cannot be applied to the contact portion between the through blades 105a and 105b and the flat conductor 101, resulting in good connection reliability. This is because there is a problem that it becomes impossible to obtain the sex.

Further, the penetrating blade 105 has a sufficient contact load.
When the a and 105b are not in contact with the flat conductor 101, the through blades 105a and 105b are oscillated by vibration or the like.
If the contact portion between the flat conductor 101 and the flat conductor 101 is displaced or loosened, the problem that the electrical connection becomes unstable and the connection reliability deteriorates easily occurs.

Therefore, the problem to be solved by the present invention is as follows.
An object of the present invention is to provide a connection structure for a piercing terminal that can be downsized and has excellent connection reliability.

[0010]

In order to solve this problem, the connection structure of the piercing terminal according to the present invention has a base and a side edge on either side of the base as described in claim 1. The first through-blade of the piercing terminal having the first through-blade standing upright is penetrated together with the flat conductor from one surface of the flat cable having the flat conductor to bring the first through-blade into contact with the flat conductor. At the same time, the first through blade protruding on the other surface of the flat cable is spirally wound to form an elastic spiral portion, and the winding surface of this elastic spiral portion is a contact portion where the first through blade and the flat conductor contact each other. The gist of the invention is that it is elastically contacted with the surface of the peripheral flat cable.

According to the connection structure of the piercing terminal,
The winding surface of the elastic spiral portion formed by spirally winding the first through blade penetrating the flat cable with the flat conductor is the first
Since the elastic blade is elastically contacted with the surface of the flat cable around the contact portion where the through blade and the flat conductor come into contact with each other, the elastic spiral portion tries to spread outward due to the spring back, and the first spiral blade is wound by the elastic spiral portion. The contact portion between the flat conductor and the flat conductor is pressed against the inner wall surface of the first penetrating blade. Also, the flat cable itself is pressed against the base portion by the winding surface of the elastic spiral portion.

Therefore, even if the width of the base portion of the piercing terminal is narrowed, a contact load can be surely applied to the periphery of the contact portion where the first through blade and the flat conductor contact each other, and the flat cable can also be securely fixed. Therefore, the connection reliability between the flat cable and the piercing terminal can be improved. That is, it is possible to obtain a piercing terminal connection structure having excellent connection reliability while achieving miniaturization.

A piercing terminal connection structure according to a second aspect of the present invention is the piercing terminal connection structure according to the first aspect, wherein the piercing terminal connection side is opposite to a side edge of a base portion on which the first penetrating blade is erected. A second penetrating blade, which is shorter than the first penetrating blade, is provided at the side edge of the stand, and the second penetrating blade is pierced together with the flat conductor from one surface of the flat cable, or there is no flat conductor. While penetrating the portion, a second penetrating blade protruding on the other surface of the flat cable is bent toward the contact portion, and the second penetrating blade is formed on the winding surface of the elastic spiral portion and the flat cable surface around the contact portion. The point is to intervene between and.

According to this piercing terminal connection structure,
The second penetrating blade penetrating the flat cable is bent in the direction of the contact portion between the first penetrating blade and the flat conductor, and then, between the winding surface of the elastic spiral portion and the flat cable surface around the contact portion. Since it is interposed, the second penetrating blade is pressed by the winding surface of the elastic spiral portion by the springback of the elastic spiral portion described above. Then, the contact portion between the first through blade and the flat conductor is pressed against the inner wall surface of the first through blade by the second through blade pressed by the pressing force.

Therefore, even if the width of the base portion of the piercing terminal is narrowed, a contact load can be surely applied to the periphery of the contact portion where the first through blade and the flat conductor contact via the second through blade, and Since the flat cable is also securely fixed,
It has excellent vibration resistance and can improve the connection reliability between the flat cable and the piercing terminal.

In this case, in the piercing terminal connection structure according to claim 1 or 2, as described in claim 3, in the elastic spiral portion, the first through blade is wound at least once or more. Are preferably formed. When the number of turns of the first through blade is less than one, the elastic spiral portion spreads out too much due to the spring back, and the pressing force by the winding surface of the elastic spiral portion is reduced, or sufficient pressing force is obtained. It is not preferable because it disappears.

Further, as described in claim 4, it is preferable that the base portion has a substantially U-shaped cross section. This is because when the base has a substantially U-shaped cross section, sufficient strength can be maintained even if the width of the base of the piercing terminal is narrowed.

Also, as described in claim 5, the first
It is preferable that a plurality of penetrating blades be provided upright. In this case, the contact area between the first through blade and the flat conductor increases,
It is possible to further improve the connection reliability.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings. The connection direction with the mating terminal (not shown) will be described as the front side.

First, the connection structure of the piercing terminal according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. 1 is an external perspective view showing a piercing terminal and a flat cable that are preferably applied to the connection structure of the piercing terminal according to the first embodiment.

The flat cable 1 is a so-called FFC (flexible flat cable), and is used for wiring in a place having a very small gap, such as a ceiling of a car, a roof lining, a door, a seat, or the like. Is.

In the flat cable 1, flat conductors 2 made of copper foil or the like are arranged in parallel at predetermined intervals, and an insulating sheet 3 made of an insulating resin such as polyethylene terephthalate.
By being sandwiched from both the front and back sides, it is formed into a flexible ribbon shape as a whole.

The piercing terminal 4 (female type in this case) is
It is formed by bending a metal plate material, and includes a connecting portion 5, a base portion 6, and a first penetrating blade 7. As a metal plate material for forming the piercing terminal 4, specifically, a metal plate material having excellent elasticity such as brass, phosphor bronze, or Corson copper alloy is preferably used.

Next, each configuration will be described respectively.
The connecting portion 5 is connected to a mating terminal (not shown) (male type in this case), and an elastic contact piece 8 is provided inside the mating terminal, and the mating terminal of the mating terminal is formed. A tab-shaped insertion portion is inserted to allow contact and conduction.

The base portion 6 is formed by extending a flat bottom portion 9 from the bottom surface of the connecting portion 5 rearward by a predetermined length, and the bottom portion 9 is formed on both side edges on the long side of the bottom portion 9. The side walls 10a and 10b are erected in a direction substantially perpendicular to, and are formed to have a generally U-shaped cross section.

The first penetrating blade 7 has a side wall 10 on one side of the base 6.
A plurality (three in FIG. 1) are provided upright from the upper end of b at predetermined intervals, and the tip end 11 thereof is sharp so that the flat cable 1 can be pierced together with the flat conductor 2. Has been formed. At this time, the length of the first through blade 7 in the longitudinal direction is at least 1 when the number of turns of the elastic spiral portion 18 (described later) formed by winding the first through blade 7 is increased.
It is set to a length that allows it to be more than once.

In this case, the side walls 10b to 3 of the base 6 are
The first through blade 7 is erected, but the first
The number of the penetrating blades 7 can be variously changed according to the connection specifications (electrical characteristics, mechanical strength, etc.) of the flat cable 1 to be connected to the flat conductor 2, and the number thereof is not particularly limited. Not something. Further, although the first penetrating blade 7 is erected on the side wall 10b, it goes without saying that the first penetrating blade 7 may be erected on the side wall 10a.

Next, the piercing terminal 4 having the above structure
A procedure for connecting the flat cable 1 with the flat cable 1 to form the connection structure of the piercing terminal according to the first embodiment of the present invention will be described. As shown in FIG. 2, the concave portion 1 of the lower caulking jig 12
After fixing the base portion 6 of the piercing terminal 4 in 3,
The end portion of the flat cable 1 is disposed above the flat cable 1, and the flat conductor 2 of the flat cable 1 is positioned above the first through blade 7.

Next, as shown in FIG. 3, the flat cable 1 is pressed from the upper side of the piercing terminal 4 and penetrated through the first penetrating blade 7 together with the flat conductor 2 of the flat cable 1. As a result, the first penetrating blade 7 is penetrated from the lower surface side of the flat cable 1 toward the upper surface side.

At this time, the first penetrating blade 7 of the piercing terminal 4
The contact portion where the flat conductor 2 of the flat cable 1 comes into contact is located at a position slightly higher than the base end portion 14 of the first through blade 7. That is, the flat cable 1 as a whole
The flat cable 1 is pierced so that the height of the flat cable 1 gradually decreases as the distance from the contact portion increases.

Next, the upper caulking jig 15 is disposed so as to face the lower caulking jig 12 with the piercing terminal 4 interposed therebetween.
The tooth mold 16 provided on the upper jig 15 for lowering
The tip portion 11 of the first penetrating blade 7 is brought into contact with. This tooth mold 1
Reference numeral 6 is for spirally winding the first penetrating blade 7 protruding to the upper surface side of the flat cable 1, and the tooth die 16 has a substantially semi-cylindrical curved surface portion 17 having a predetermined radius of curvature. Are formed.

The tooth mold 16 is provided with a tip portion 11 of the first penetrating blade 7.
When the upper crimping jig 15 is further lowered after abutting against, the tip portion 11 of the first penetrating blade 7 is gradually rounded while being guided along the shape of the curved surface portion 17. And tooth mold 1
The tip end portion 11 of the first penetrating blade 7 protruding from the inside of the elastic member 6 is elastically wound in a spiral shape toward the inside to form an elastic spiral portion 18.
Is formed. As shown in FIG. 4, the elastic spiral portion 18 is formed by winding the winding surface until it comes into contact with the surface of the flat cable 1 around the contact portion where the first through blade 7 and the flat conductor 2 contact each other. However, it is preferable that it is wound at least once or more.

After the elastic spiral portion 18 is formed in this manner, the piercing terminal 4 is removed from the upper caulking jig 15 and the lower caulking jig 12 to remove the flat cable 1
The connection of the piercing terminal 4 to the connection is completed, and the connection structure of the piercing terminal according to the first embodiment of the present invention is obtained.

According to this piercing terminal connection structure,
The winding surface of the elastic spiral portion formed by spirally winding the first through blade penetrating the flat cable with the flat conductor is the first
Since the elastic blade is elastically contacted with the surface of the flat cable around the contact portion where the through blade and the flat conductor contact, the contact surface between the first through blade and the flat conductor is the inner wall surface of the first through blade due to the winding surface of the elastic spiral portion. Is pressed by.

The operation of the elastic spiral portion 18 in the connection structure of the piercing terminal according to the present invention will be described in more detail with reference to FIGS. 5 to 7 (the flat cable is omitted in the drawings). After the bending process of spirally winding the first penetrating blade 7 of the piercing terminal 4 by the tooth mold 16 of the tool 15 to form the elastic spiral portion 18 (see FIG. 5), the upper crimping jig 15 is moved. When the load is raised to remove the load, the elasticity of the elastic spiral portion 18 causes some deformation to be restored during bending. That is, the elastic spiral portion 18 has elasticity as a whole by the spiral spring, and tends to spread outward by the spring back (see FIG. 6).

Therefore, the contact surface between the first through blade 7 and the flat conductor 2 is pressed against the inner wall surface of the first through blade 7 by the winding surface of the elastic spiral portion 18, so that the first through blade 7 and the flat conductor 2 are separated from each other. A contact load is generated around the contact portion inside the first penetrating blade 7 that makes contact. Further, the flat cable 1 itself is also pressed against the upper end of the side wall 10a by the winding surface of the elastic spiral portion 18, so that the flat cable 1 is also securely fixed.

At this time, when the elastic spiral portion 18 is not formed in consideration of the return amount of the deformation after bending caused by the spring back, that is, the winding surface of the elastic spiral portion 18 is the same as the first through blade 7. When the flat cable 1 is in contact with the surface of the flat cable 1 around the contact portion where the flat conductor 2 comes into contact with the flat conductor 2 and is not wound at least once or more, as shown in FIG. The winding surface of the swells too outwardly and the spiral shape cannot be maintained.

Therefore, the pressing force by the winding surface of the elastic spiral portion 18 becomes small, or the pressing force cannot be sufficiently obtained, so that the first through blade 7 and the flat conductor 2 are securely contacted with each other around the contact portion. It becomes impossible to apply a contact load to. From this, it can be said that it is preferable that the elastic spiral portion 18 is wound so that the winding surface of the elastic spiral portion 18 does not spread too outwardly, in consideration of the amount of return of the deformation caused by the springback after bending. .

According to the piercing terminal connection structure according to the first embodiment of the present invention described above, even if the width of the base portion of the piercing terminal is narrowed, the first through blade and the flat conductor are securely contacted with each other around the contact portion. Since a contact load can be applied to the flat cable and the flat cable is securely fixed, the flat cable and the piercing terminal can be connected reliably without slipping or loosening even if vibration or the like is applied. It is possible to improve. That is, it is possible to obtain a piercing terminal connection structure having excellent connection reliability while achieving miniaturization.

Next, the connection structure of the piercing terminal according to the second embodiment of the present invention will be described with reference to FIGS. 8 to 10. In the following, points different from the connection structure of the piercing terminal according to the first embodiment will be mainly described. Figure 8
FIG. 9 is an external perspective view showing a piercing terminal and a flat cable that are preferably applied to the piercing terminal connection structure according to the second embodiment of the present invention.

The piercing terminal 20 includes a connecting portion 21, a base portion 22, a first penetrating blade 23, and a second penetrating blade 24. In this piercing terminal 20, the second penetrating blade 24 stands facing the first penetrating blade 23 upward from the upper end of the side wall 25a opposite to the side wall 25b on which the first penetrating blade 23 is erected. It is set up. Further, the second through blade 24 is formed shorter than the length of the first through blade 23 in the longitudinal direction, and the tip portion 26 thereof has the flat cable 28 like the tip portion 27 of the first through blade 23. The flat conductor 29 is sharply formed so that it can be pierced together.

Next, the piercing terminal 2 having the above structure
0 and the flat cable 28 to establish a connection structure of the piercing terminal according to the second embodiment of the present invention with reference to FIGS. 9 and 10 (in the drawings, an upper crimping jig and a lower crimping jig). Tools are omitted.).

As shown in FIG. 9, the flat conductor 2 of the flat cable 28 is provided above the first penetrating blade 23 of the piercing terminal 20.
Align so that 9 is located. At this time, the flat conductor 29 of the flat cable 28 is provided above the second penetrating blade 24.
May be positioned so that the position of the flat conductor 29 is not present, that is, the insulating sheet 30 may be positioned as shown in FIG.
It can be appropriately adjusted depending on the width of the flat conductor 29 of the flat cable 28 used in the width direction.

After aligning the two in this way, the flat cable 28 is pressed from above the piercing terminal 20 so that the flat conductor 29 of the flat cable 28 and the first penetrating blade 23 are penetrated, and the insulating sheet 30 is also inserted. The second penetrating blade 24 is passed through. As a result, the first penetrating blade 23 and the second penetrating blade 24 are penetrated from the lower surface side of the flat cable 28 toward the upper surface side. At this time, the contact portion where the first through blade 23 of the piercing terminal 20 and the flat conductor 29 of the flat cable 28 contact each other is located at a position slightly higher than the base end portion 31 of the first through blade 23.

Next, as shown in FIG. 10, the second penetrating blade 24 protruding toward the upper surface of the flat cable 28 is bent toward the contact portion where the first penetrating blade 23 and the flat conductor 29 come into contact with each other, and thereafter, The first penetrating blade 2 by an upper swaging jig (not shown)
3 is wound in a spiral shape to form the elastic spiral portion 31. In the connection structure of the piercing terminal according to the second embodiment of the present invention, the elastic spiral portion 31 is formed by being wound until its winding surface comes into contact with the surface of the bent second through blade 24. However, it is preferable that it is wound at least once or more.

After the elastic spiral portion 31 is formed in this manner, the piercing terminal 20 is removed from the upper and lower crimping jigs (not shown) to remove the flat cable 2 from the flat cable 2.
The connection of the piercing terminal 20 to 8 is completed, and the connection structure of the piercing terminal according to the second embodiment of the present invention is obtained.

According to this piercing terminal connection structure,
The second penetrating blade penetrating the flat cable is bent in the direction of the contact portion between the first penetrating blade and the flat conductor, and then interposed between the winding surface of the elastic spiral portion and the flat cable surface around the contact portion. Therefore, the second through blade is pressed by the winding surface of the elastic spiral portion by the springback of the elastic spiral portion described above. Then, the contact portion between the first through blade and the flat conductor is pressed against the inner wall surface of the first through blade by the second through blade pressed by the pressing force.

Therefore, even if the width of the base portion of the piercing terminal is narrowed, the contact load can be surely applied to the periphery of the contact portion where the first through blade and the flat conductor contact via the second through blade, and Since the flat cable is also securely fixed,
It has excellent vibration resistance and can improve the connection reliability between the flat cable and the piercing terminal.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments and various modifications can be made without departing from the spirit of the present invention. Is. For example, in the above-described embodiment, the FFC (flexible flat cable) is used as the flat cable for connecting the piercing terminals. However, a flat cable having a flat conductor such as an FPC (flexible printed circuit board) is also available. It is also applicable to, and is not particularly limited.

Further, in the above-mentioned embodiment, the connecting portion of the piercing terminal has a female shape, but it may have a tab-like male shape or a round shape.
It is not particularly limited.

[0051]

According to the piercing terminal connection structure of the present invention, even if the widthwise dimension of the piercing terminal is designed to be small (narrower pitch), the contact portion where the first through blade and the flat conductor contact each other The contact load can be reliably applied to the periphery, and the connection reliability can be improved.

[Brief description of drawings]

FIG. 1 is an external perspective view showing a piercing terminal and a flat cable that are preferably applied to a connection structure for a piercing terminal according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a positional relationship between a piercing terminal, a flat cable, and a caulking jig in the piercing terminal connection structure according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a state in which a flat cable is passed through a first penetrating blade of a piercing terminal.

FIG. 4 is a view showing a connection structure of piercing terminals according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a state after the bending process for forming the elastic spiral portion is completed.

FIG. 6 is a diagram for explaining the operation principle of the elastic spiral portion.

FIG. 7 is a diagram showing a state of the elastic spiral portion when the elastic spiral portion is not sufficiently wound.

FIG. 8 is an external perspective view showing a piercing terminal and a flat cable that are preferably applied to the connection structure of the piercing terminal according to the second embodiment of the present invention.

FIG. 9 is a diagram showing a positional relationship between a piercing terminal and a flat cable in a piercing terminal connection structure according to a second embodiment of the present invention.

FIG. 10 is a view showing a connection structure of piercing terminals according to the second embodiment of the present invention.

FIG. 11 is a diagram showing a piercing terminal and a flat cable when the width L of the base is relatively large.

FIG. 12 is a diagram showing a state where a flat cable is penetrated through a penetrating blade of the piercing terminal of FIG. 11.

FIG. 13 is a diagram showing a conventional connection structure of piercing terminals when applying an inward contact load.

FIG. 14 is a diagram showing a connection structure of a conventional piercing terminal when an outward contact load is applied.

[Explanation of symbols]

1 Flat cable 2 Flat conductor 4 Piercing terminal 6 base 7 First penetrating blade 9 Bottom part 10a side wall 10b side wall 18 Elastic spiral part 20 Piercing terminal 22 base 23 First Penetrating Blade 24 Second penetrating blade 25a side wall 25b side wall 28 Flat cable 29 Flat conductor 30 insulating sheet 31 Elastic spiral part

Continued front page    (72) Inventor Saito Nei             1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi             Auto Network Technical Laboratory Co., Ltd. F-term (reference) 5E012 AA25                 5E077 BB05 BB11 DD07 DD11 FF09                       HH02 HH07 JJ20

Claims (5)

[Claims] 1. A first through-blade of a piercing terminal comprising a base and a first through-blade that is provided upright from a side edge on either side of the base, from a flat cable having a flat conductor on one side thereof. While passing through the flat conductor to bring the first through blade and the flat conductor into contact with each other, the first through blade protruding from the other surface of the flat cable is spirally wound to form an elastic spiral portion. A connecting structure for a piercing terminal, wherein the winding surface of the portion is elastically contacted with the surface of the flat cable around the contact portion where the first penetrating blade and the flat conductor contact each other. 2. A second penetrating blade, which is shorter than the second penetrating blade and which is opposed to the first penetrating blade, is provided on the side edge of the base portion on which the first penetrating blade is erected, the side edge being opposite to the side edge. A through blade is penetrated from one surface of the flat cable together with the flat conductor, or a part without a flat conductor is penetrated, and a second through blade projected on the other surface of the flat cable is bent toward the contact portion, 2. The piercing terminal connection structure according to claim 1, wherein the second penetrating blade is interposed between the winding surface of the elastic spiral portion and the surface of the flat cable around the contact portion. 3. The connection structure for a piercing terminal according to claim 1, wherein the elastic spiral portion is formed by winding the first penetrating blade at least once. 4. The connection structure for a piercing terminal according to claim 1, wherein the base has a substantially U-shaped cross section. 5. The connection structure of piercing terminals according to claim 1, wherein a plurality of the first penetrating blades are provided upright.