DE7415876U - Screw-like fastener - Google Patents

Description

THE BRITISH SCREW COMPANY LIMITED, Leeds, York, (Great Britain)

Screw-like fastener

The invention relates to a screw-like fastening element for the mutual connection of at least two adjacent panel-shaped or plate-shaped components of known thickness, with one at its one Head arranged at the end for rotating the fastening element around its longitudinal axis; with a section of a self-tapping one running below the head Thread; with a ballistically designed tip arranged at its other end, the maximum Cross-section dimension is about as large as the core diameter, but smaller than the outside diameter

59

Bremen office:
D 2000 Bremen 1
P.O. Box 786. l ^: eklstrasse 24
• Telephone did 21) ' 74044
Icle " 24-1 M5" hopatd

Οίίΐμπιπιηι, ΒΓίΊηηι

Cremen accounts: Bremer Bank, Bremen (BLZ 29080010) 1001449

PScIiA Hamburg

(BLZ 2C010020) 1260X5-202

7415876 07/24/75

Munich office:
D-8000 Munich 90 Schlotthauer Straße 3 Telephone: (089) 652321

Tclegr. : Telepatcnt, Munich

BOEHMERT & BOEHMERT. y /

of the thread; and with a smooth cylindrical cut between the thread a1) and the ballistic point Shank section whose diameter is smaller

than the maximum cross-sectional dimension of the ballistic tip "

The subject invention is intended to be two or to connect more components to one another without first having a guide hole in the components to be connected to one another is appropriate.

There are several types of self-tapping screws known, which are also known as self-drilling screws. These self-drilling screws have on their Screwing in a drilling section which causes a drilling process when turning the screws, with the consequent Tip of the screw can drill its own pilot hole in a component. In cases where driving force, normally electricity, is available, the self-drilling or self-tapping screws for example also used for cold rolled steel parts for the construction industry xverden. The self-drilling ones cut Screws into the metal to form a hole and only leave one such metal thickness at a time It stands that a screw thread can be cut into this. The degree of attachment or the size the allowable stress is therefore limited by the thickness of the metal section through which the hole is drilled would be »

Furthermore, such fastening means for use in metal parts are known that have such a design have front end portion that they can be used by impact, the

Impact causes the end of the screw to penetrate the metal. These fasteners are used essentially by means of cartridge-operated tools, since the fasteners are primarily used in the construction industry and there on the spot of assembly. A "cartridge-operated tool" is to be understood as a tool which is operated by igniting the explosive charge of a cartridge or by igniting a combustible fuel, the ignition causing a considerable increase in pressure due to the expansion that occurs. The force caused by the ignition or explosion r ~ \ plosion is then used to exert a blow or impact to the fastener. Such tools have the advantage that they are completely independent and can be used independently of any power source such as an electrical connection or compressed air. Because such a power source is often not readily available at an assembly site.

These known fasteners are operated by a cartridge Tool used have either smooth or corrugated pins or handles and have a penetration point or portion, this penetration portion causing the Qi to penetrate metal of a component after the shooting process has been initiated by ignition. These two types of fasteners have a limited one

! Area of application, since first of all the holding power of the

j penetration section after driving into a

j the steel support part is not large enough for many applications,

what, for example, is then pail when outward

j directed tensile forces exerted on the fastening means

j ^- become. Typical examples of this are the attachment of roof plates and wall cladding panels to roof frames,

·. ··. Purlins, rails, pillars and the like, such as ; - Find supporting parts in the construction industry. In the-

BOEHMERT & BOEHMERT

like applications are on the fastening means often considerable pull-out loads are exercised, which result from external forces, polygamy, can arise, for example, by wind load on the cladding panels or the like.

Heretofore there has not been a satisfactory way of using a self-tapping threaded fastener on the stem of the fastener and using a cartridge operated tool to drive the fastener. This essentially arises from two problems. Ü

On the one hand, the front drive-in section of such fastening elements, after it has been driven into a component such as a roof purlin made of metal as a result of the ignition and shooting, causes considerable resistance to rotation of the fastening element, which is, however, necessary in order to create a corresponding thread cut or shape. This resistance can be so great that, when the fastening element is rotated, it causes the head of the fastening element to shear off, so that the fastening element is effective λ lo! 3. Second, after the ignition and shooting

/ - \ of the fastening element in a component made of metal the first thread turns of the shaft by the occurring impact or impact in the one formed by the penetration portion Penetrate hole. Because the largest thread diameter is necessarily larger than that of the penetration section the fastening element formed hole diameters, the first threads that are driven into the hole are either substantially deformed or completely destroyed. This makes further insertion of the fastening element ^ into the components impossible.

JI- - 7415876 7/24/75

BOEHMEIOT & BpEHMBRT. ,,

It can be readily seen that it would be of considerable benefit if a self-tapping screw were successful to be used with a cartridge operated tool. Then you would be in the, for example Construction industry will be able to benefit from the well-known advantages of self-tapping threads on the one hand, as well as from the operational ones To make use of the advantages of such cartridge-operated tools on the other hand.

The present invention is based on the objective to improve the known fastening elements while avoiding their disadvantages, and a screw-like fastening element of the type described above to create which to use for a cartridge-operated tool without shearing off the screw head or damaging the thread.

As a solution to this problem, the invention provides that the maximum cross-sectional dimension of the ballistic The tip is not smaller than the core diameter of the Thread and that the smooth cylindrical shaft portion has an axial length which is at least as great like the total thickness of the components to be joined together.

It has proven to be particularly advantageous if the thread of the threaded section is a buttress thread is trained.

To create an optimal sealing effect, the invention also provides that on the cylindrical portion of the fastening element, a deformable disc is arranged, wherein in an embodiment of the invention between a metal washer can be placed on the head and the deformable washer. One particularly appropriate training arises when in

7415876 07/24/75

BOEHMEfir S BCTEHMERT ·;

¹ 4 »•» III ι

Another embodiment of the invention, the deformable disc and the existing metal washer with each other are connected.

The attachment of the fastening element according to the invention can preferably take place in that the to one another connecting components are arranged at least partially overlapping each other, that then the ballistic Section of the fastening element is driven by means of impact through the components that the cylindrical Section of the shaft after the impact lies in the hole formed in the components, and that finally a Torque is applied to one end portion of the fastener to enter the hole formed nut thread corresponding to the thread of the component

to form until the components are connected to one another, the impact preferably being generated by shooting.

As has already been indicated above, there is an important field of application of the fastening means according to the invention in the construction sector, in particular when fastening roof and wall panels, cladding and the like by means of screw means, it being a necessary requirement that the screw assembly after insertion is weatherproof.

The screw-like fastening means preferably has a head which is designed such that it to be turned with a suitable tool such as a wrench, screwdriver or the like. To the To create the required sealing effect, a sealing washer is provided as already mentioned above, which under the underside of the head and the outside of the sheet metal to be fastened can be clamped. aside from that

or a metal washer can be used instead be provided. The sealing washer, which is preferably connected to the metal washer, can consist of a suitable one

7415876 07/24/75

BOEHMERT & BOEH ^ ERT ·: · / V

Made of plastic, which has good corrosion resistance and is also deformable to a good degree under the clamping pressure generated by the head To achieve a sealing effect on the screw shaft at the point where it penetrates through the outer sheet, as well as a good sealing effect to the sheet metal itself at the section surrounding the screw shaft.

Such a washer can also be used as a centering means for the shaft of the fastening element be used when this is in the socket of the cartridge-operated Tool is located and is ready for operation. From that point of view, the hole is in the Disc preferably slightly smaller than the largest cross-sectional dimension of the end portion of the fastening element, so that the washer can be slid over this section and then firmly on the smooth cylindrical Section of the screw shaft is seated. In cases where a metal washer in addition to the sealing washer is required under the screw head, this can be pushed onto the shaft before the sealing washer is attached so that the sealing washer prevents the metal washer from sliding off the shaft. on In this way, a structural unit consisting of a screw, metal washer and sealing washer is created, which, for example, can already be prepared at the place of manufacture, i.e. completely manufactured, so that the person who carries out the application, no difficulties in applying the discs on the Has screws and there is no risk that the lack of washers is overlooked, so that the fasteners without the disks being attached.

In this way, an excellently suitable fastener has been created to components connect with self-tapping screws using cartridge operated tools. the

7415876 24.07.75

BOEHMERT & BOBI-IMERT

Screw eingocoiios- through the tool into the components' ^ sen. The length of the tool's ram path is carefully controlled so that only the ballistic end portion of the fastener completely passes the components before the screw comes to rest. Since the screw does not get further into the components at this point in time, ie during or after firing, the threaded section of the screw shaft is not brought into contact with the components, so that it is ensured that the thread is not damaged.

ji -f- \ Since the screw has a flat cylindrical section on its shaft with a diameter that is smaller than the largest diameter of the ballistic section,

it follows that the ballistic section after dom Ignition of the screw created hole necessarily must be larger in diameter than the diameter of the unthreaded cylindrical shaft, cut. Since this section of the shaft continues

. is arranged between the ballistic section and the threaded section and has an axial length, which is at least as large as the hole depth after through. arcing through the ballistic section, the

Screw can simply be rotated relative to the components, () since there is a gap between the screw and the components. In this way the problem of excessive resistance to turning the screw is avoided.

The invention and preferred refinements of the invention are illustrated below using exemplary embodiments further explained on a drawing. It shows:

Fig. '1 is a side view of a screw-like fastening element self-tapping thread with washer located under the screw head Made of metal with the omission of a sealing washer;

" 8th _

7415876 24-07.75

BOEHMERT & BOEHMERT

Fig. 2 shows a cross section through a screw

blank for the screw according to FIG. 1 • before application of the thread;

i Fig. 3 is a side view of a Teilschnit-. tes an arrangement for attaching a roof panel to a roof frame by means of a Befcstigungselementes ■

according to FIG. 1 in a first stage; '.

FIG. 4 shows a representation corresponding to FIG. 5 at the ead stage, when the screw is fully inserted to . To clamp the roof plate firmly to the roof frame;

5 shows a lateral cross section through a device for attaching a fastening element 1 to 4 in the idle state with inserted screw;

Figure 6 is a fragmentary view corresponding to Figure 3 with the device loaded; and

FIG. 7 shows a line 6 corresponding to FIG. 3

Representation after ignition or after the screw has fired in two components.

FIG. 1 shows a screw which has a hexagonal head 10 at one end and a ballistic head at its other end has formed portion 11. A thread 12 extends along the shaft from below the Head 10 and a smooth cylindrical portion 13 extends between the front end of the thread 12 and the inner end of the ballistic section 11. The thread 12 is a hardened, self-tapping thread, which, however, is preferably is not necessarily designed as a buttress thread, as shown in the drawing, in order to maintain the holding force of the thread when it is fully inserted into metal parts, as can be seen in Fig. 4- is where the saw form cies thread for an additional Resistance to pulling out the fastening

7415876 07/24/75

BOEHMERT:

supply means under axial stress. Other "Well-known head shapes can be used, but it is suitable The head has a hexagonal shape, especially for fastening building panels, as the screw is by means of rotated a breast vault or the like provided with a hexagonal receptacle at its working end by hand can be. · ,,

The ballistic section 11 is preferably, although not necessarily, smooth and free of any grooves, grooves, slots and the like. It r has a tapering shape, which is known to be particularly suitable for explosively moving projectiles for penetrating or penetrating hard materials.

A shoulder 14- is formed between the smooth cylindrical section 13 of the shaft and the inner end of the section 11. The largest diameter of the ballistic section 11 is located on the shoulder 14 or in the immediate vicinity of it. The relationship between this largest diameter of the section 11 and the largest diameter of the thread 12, so its acute diameter, is such that Q) this diameter of the section 11 must be smaller than the major diameter of the thread 12 to ensure that around the circumference Of the hole created by the section 11, sufficient material remains around that the tips or planks of the thread 12 cut into the metal or deform it and in this way form a female thread. The maximum diameter of the section 11 must not be too large, otherwise not enough metal remains around the circumference of the hole, so that the radial depth of the nut thread that is cut

- 10 -

7415876 07/24/75

BOEHMJERl & BQEHMERT

or is formed, would not be sufficient to achieve the desired full or substantially full thread engagement between the thread 12 and the metal so that the resistance to pull-out stress becomes serious would be weakened. On the other hand, the maximum diameter of the section 11 must not be too small, because this would require too much torque to turn the screw and cause the thread 12, to cut or form a nut thread. Too much torque can damage the thread 12 or in extreme cases lead to the head 10 shearing off the screw.

The axial length of the smooth cylindrical portion 13 is also an important parameter. This length and their relationship to thread 12 will be described below in the description of the operation of the fastener discusses how this is described there with reference to the representations in FIGS.

Fig. 5 shows a shooting tool with a housing 30, in which a cylindrical body 35 is slidably disposed, hereinafter referred to as a carriage. Within of the carriage 35 is a telescopic and slidably arranged bush 36, which on its front ; End section has a foot 37. The foot 37 has

a front head side 38 to be brought into engagement with the work site, which in a front or end view, d, h "So in a side view from the right end

j in Fig. 5, runs substantially at right angles.

j At its inner end is the socket 36 with a buffer

<which has a rubber ring 39 and a buffer ring 40

j made of steel, which has the outer circumference of the rubber

.. ': ring 39 overlaps, and its front in the open

; - "or the non-compressed state of the rubber ring 39

- 11 -

BOEHMERT _: & BQEHM J RT.

from the inner end face of the socket 36 is removed.

An expansion chamber 41 is attached to the rear drawer of the cylindrical body 35. A helical compression spring 42 acts against a shoulder of the expansion chamber 41 and a shoulder of the steel buffer ring 40.

A plunger designated as a whole by 43 has on his rear end a cylindrical portion 44, which in the position shown in Fig. 5 with a tight fit is fitted into the expansion chamber 41. In front of the section 44, the plunger 43 has a retracted Ab-V- / cut 45, and in front of this its diameter is constantly growing and forms a frustoconical portion 46, on which is followed by a smooth cylindrical section 47. The remaining part 48 of the plunger 43 has a • reduced Diameter of circular cross-section and is fitted with a sliding fit in the bore of the bushing 36, In this way, a forward-facing shoulder 49 is obtained, which is connected to the rear of the buffer ring 40 can cooperate in the manner described below. ^

The plunger 43 "is made of high strength steel in order to act on this Way to ensure maximum shock resistance.

The screw is shown in the position inserted into the front end of the tool. There is also a window 18 made of plastic placed on the smooth cylindrical portion 13 to the screw shank in the bore of the to center the front end sections of the tool.

The tool is prepared for firing by placing the head 38 against the outer surface of a fixture Sheet metal is pressed, which is to be attached, for example, to a roof frame. A forward movement is thereby: carried out until the position shown in Fig. 6

- 12 -

7415876 24.0775

BOEHMERT & BOEHMERT

development is reached, in which the spring 42 is compressed / \ J and the portion 44 of the plunger 43 is located completely within the expansion chamber 41 and at the front end of the part 48 of the plunger is in engagement with the head 10 of the fastener. In the tensioned or fully loaded state of the tool, as shown in Figure 6, the distance G between the shoulder 49 of the plunger 43 and the front of the steel buffer ring; 40 equals the distance by which the ram moves forward \

moves when the cartridge is fired. Since the front;

The end of the plunger is engaged with the head 10 of the fastening element, the tip of which is in turn engaged with the workpiece, this is also the distance by which the fastening element is caused to move into the workpiece or to penetrate it; _.: Gen The arrangement is preferably such that the rubber \ ring 39 is not completely compressed when;

the shoulder 49 with the face of the buffer ring 40 \

comes into engagement so that the buffer ring 40 does not strike the inner end of the sleeve 39.

The remaining parts of the gun operate in the conventional ί manner. When the tool is in a stretched or durchgeladenem {state, the trigger 32 is pulled, so that the firing pin assembly 33 applied to the cartridge located in a magazine assembly 34th The firing of the cartridge causes a large increase in pressure in the combustion chamber: which causes the plunger 43, which is in contact with the fastener, to move through the sleeve 36 and in turn causes the ballistic portion 11 of the Fastening element penetrates the components representing the workpiece.

In FIGS. 3 and 4, the screw shown there is used for this purpose used to attach a roof plate 15 to a roof frame 16, with the screw just below her head

BOEHMSRT & BOEIlMERX

t · I I

• ' It,

' (11 j

• 't «) ■ ι <

10 is provided with a washer 17 made of metal and a sealing washer 18. This serving the poetry Washer 18 is made of a suitable plastic that is corrosion resistant and under the head 10 above the "metal washer 17 applied clamping pressure. is easily or willingly deformable so that it is fastened in the The final state of the arrangement assumes the form shown in FIG.

The inner diameter of the washer 18 is slightly smaller than the largest diameter of the Abx-x cut 11, so that after sliding it over the section

11 held on the smooth cylindrical section 13 is and in the manner described above at the beginning to center the screw shaft in the socket of the tool can serve.

After ignition, the screw assumes the position shown in FIG. It can be seen that the ballistic section 11 has completely penetrated the metal of the parts 15 and 16. Furthermore, as a result of the impact that occurs when the section 11 is passed, the metal in the vicinity of the screw shaft is drawn in in the direction of the movement of the section 11 downwards, so that the outer surface of the plate 15 is now sunk and one in the has a substantial frustoconical impression in its outer surface. The passage of section 11 also causes metal of parts 15 and 16 to be drawn or extruded in the area surrounding the shaft, which can be seen particularly clearly in the sheet metal of part 16, which is the thicker of the two sheets in which it can be observed that the axial length of the metal of the part 16 in the area immediately surrounding the screw ^{shaft is greater by a certain amount than the original thickness of the r} file 16.

BOEl IMERT, & BOJiHMERT. S "

In this state, the smooth cylindrical portion 13 of the shaft is arranged in the hole which is in the Parts 15 and 16 has been formed. The AbV section 13 is essentially loose, so that it is easy Way can be rotated by hand. It can be seen that to achieve this position, the axial length of the Section 13 at least equal to the axial length of the metal of parts 15 and 16 in which the section 13 must be immediately surrounding section and is preferably slightly larger. This thickness doesn't stop there alone the original thickness of parts 15 and 16, but also Any additional thickness that occurs in the process of drawing or extruding the metal of these parts, as described in the previous section.

Practical tests have shown that there is a successful use and application of this fastener it is important that the axial length 'of the reduced diameter section 13 is sufficiently long, .so that another section of the reduced section 13 protrudes on both sides of the hole. If the axial length is less than this critical distance, so this could lead to the thread 12 coming into contact with the part 15, whereby the first thread turns could be destroyed.

So that the screw can securely hold the components together, it is for the threaded section 12 of the shaft required that this has an axial length at least as great as the combined thickness of the Components through which it passes or is intended to pass. Since the axial length of the reduced diameter section 13 has this critical minimum length and the axial length of the reduced portion 13 is not greater than any necessary for economic reasons should be, the axial length of the thread

- 15-

7415876 07/24/75

BOEHMERT & DOEHMIiKT

section 12 must be at least as large as the axial one Length of the reduced diameter section 13 and preferably slightly larger.

It can be seen that the washer 18 on its underside - there is the stop! Sheet metal 15 facing side ~ a tapering cone umpfförmi ge surface 19 has. The reason for this lies in that this part 19 first with the frustoconical Countersink of the plate 15 comes into engagement when the screw in the Pig. 4 position shown after / -S, is pulled down. In this way, the underlay

Sealing washer arranged in an ideal way in this depression> ■ or recess and allows a final tightening of the head 10 downward, resulting in the state shown in Fig. 4 result in which the flat washer-Diohtscheibe 18 downwardly and inwardly into the frustoconical depression is deformed into it so that the washer is forced into intimate contact with the threads of the thread 12 and also with the parts of the sheet metal 15 'which immediately surround the thread, in order in this way to ensure that a watertight seal is formed.

For ease of arrangement, the other side of the washer 18 is also frustoconical with the same Section 19 formed so that the washer is pushed onto the screw shaft in each direction can be.

The position of the parts shown in Fig. J is in a certain way theoretical, since in practice the impact force the leading end of the thread 12 will cause the bore of the plastic washer 18 at least ■ partially penetrate, with the front end of the thread 12 through the washer in the direction of the

- 16 -

7415876 07/24/75

• «J I ο« ι

- «« 1 (1

Surface of the sheet 15 or in contact with this can come.

To complete the arrangement, a plastic cap can be provided which is frictionally engaged with the head can be connected or an elastic or a clamp connection to the head 10 can have, uia on this Way to ensure further watertightness.

7415876 07/24/75

Claims (2)

Protection claims 1. Screw-like fastening element for the mutual ■ connection of at least two adjacent panel or plate-shaped components of known thickness, with a head arranged at one end for rotating the fastening element about its longitudinal axis; with a section of a self-tapping thread extending below the head; with one on its other end arranged ballistically shaped tip, the maximum cross-sectional dimension of which is approximately as large as the core diameter, but smaller than the outer diameter of the Thread; and with a smooth cylindrical shaft section, the diameter of which is smaller than, arranged between the threaded section and the ballistic tip the maximum cross-sectional dimension of the ballistic tip, characterized in that the maximum cross-sectional dimension 59 Bremen office:
D-2800 Bremen 1
P.O. Box 786, Fcldstraßc 24
Telephone: (0421) »74044
Telex: 244958 bopatd
Telcgr. : Diagram, Bremen Bremen accounts : Bremer Bank, Bremen (BLZ 29080010) 1001449 PScIiA Hamburg _. . _ (BLZ 2OU10020) 126083-202 7415876 24.97.75 Munich office: D-8000 Münclict. * 'SchlollLaucr Straße *, phone:' 089) 652321 Tclegr. : Tclepatent, Munich dimension of the ballistic tip (11) is not smaller than the core diameter of the thread (12) and that the smooth cylindrical shaft section (13) has an axial length which is at least as large as the total thickness the components to be connected to one another (15 »16). 2. Fastening element according to claim 1, characterized in that that the axial length of the thread section (12) is at least as large as the axial length of the smooth cylindrical shaft section (13). 7415876 07/24/75