CN1112951C - Overload-protected building element for constructional building set - Google Patents

Abstract

A toy building device comprises a screw and a building component. The screw has a hollow plastic body with a threaded portion formed on its exterior. The building component has a plastic bushing with a corresponding internal threaded portion. The bushing or screw has at least one groove formed along its length, extending along the threaded portion. Therefore, the threaded portion will separate before being damaged by a possible overload.

Description

Overload protected building elements for structural building installations

field of invention

The present invention relates to a toy construction set. The invention also relates to a screw and a building element.

current technology

Toy construction sets having building elements of this type are known and sold under the trademark " ^DUPLOTOOLO® ". The above-mentioned members are made of plastic such as ABS resin, intended to protect them from damage caused by mechanical overload. Accordingly, the applicant for this patent has previously filed an international patent application PCT/DK95/00198 concerning torque-limiting connections for use in screws or nuts.

Summary of the invention

It is an object of the present invention to provide a toy construction device consisting of an externally threaded screw and a construction element with an internally threaded bush, where even a high torque is applied to the used screw On parts that are screwed together, it also protects those parts from damage.

To this end, the present invention provides a toy construction device comprising a screw having a hollow plastic stem forming a threaded portion on the outside, and a construction element having a plastic lining with a corresponding internal thread portion A sleeve, characterized in that the bush or screw forms at least one groove along its length, said groove extending along the threaded portion.

In particular, the bush and/or the screw form several longitudinal grooves having the same axial extent and segmentally dividing the screw and/or the bush into several elastic parts.

According to a further aspect of the present invention there is provided a screw for toy construction set comprising a hollow plastic rod the outside of which forms a threaded portion which fits onto another component contained in the toy construction set In a bore with a corresponding threaded portion, the screw is characterized in that the screw is formed along a portion of its length with at least one groove extending through the threaded portion.

In particular, the screw forms several longitudinal grooves which have the same axial extent and divide the screw segmentally into several elastic sections.

In particular, the screw has two grooves, thus making the elastic part semi-cylindrical.

In particular, the screw has three equally spaced grooves in the circumferential direction.

According to a further aspect of the present invention there is provided a building element for a toy construction set comprising a cylindrical plastic bushing having an internally threaded portion for receiving a screw having a corresponding threaded portion which The bushing is characterized in that along its length part at least one groove is formed, said groove extending through the threaded part.

In particular, the bush forms several longitudinal grooves having the same axial extent and divides the bush segmentally into several elastic parts.

In particular, the bushing has two grooves, thus making the elastic part semi-cylindrical.

In particular, the bushing has three equally spaced grooves in the circumferential direction

According to the invention, both the screw and the bushing are made of plastic.

Thus, it ensures that the screw can be compressed, or the bush can be expanded, if the part is subjected to a torque exceeding a certain magnitude. It should be noted that if the screw is subjected to a transverse torque at a distance from the thread, the two parts will separate from each other. Thus, it ensures that the threaded parts can be disengaged from each other if the screw is tightened beyond full tightening. This provides a limited torque coupling to prevent torque induced overloads.

According to the invention, there are preferably several grooves which divide the threaded part into several elastic beams in sections.

If the screw is provided with grooves, it may be advantageous for the grooves to be interconnected by a diagonally or radially diverging groove in the generally blunt threaded end of the screw.

If the grooves are provided in a bushing of a building element, the bushing is suitably arranged so as to extend into the building element at right angles from one of the planar sides.

The bushing is usually secured to the plane of the building element by a quick connection irreversible to the user. Here, it will be the end face of the bushing that leaves the plane, which is equipped with slots for flexible deflection. Alternatively, the two ends of the bushing may be connected to each other on the perimeter, and then here is exactly the slotted central threaded portion of the bushing, allowing for flexible deflection.

The invention also relates to a screw having a hollow shaft made of plastic with an external threaded portion. The screw fits into a hole in another component included in the toy construction set, the hole having a corresponding threaded portion. The hole is usually in the form of a plastic injection molded bushing which acts as an insert in the building element. Along a portion of the screw's shank length, the screw forms a groove extending along the threaded portion towards the end of the screw.

If the screw is loaded in its longitudinal direction by a tensile force generated by a torsional or transverse force, its grooved shank acts as elastic beams which, when the tension reaches a certain magnitude, bend inwards and thus cooperate with each other. The threaded parts of the screw disengage from each other, and the screw is thus loosened from the building element without permanent damage.

In a preferred embodiment, the screw has two grooves located diametrically opposite one another. In a particularly suitable embodiment, the screw forms three longitudinal grooves which divide the threaded portion of the screw into three segments of equal size. The resulting elastic beam ensures that the screw is loosened with the same force regardless of the direction of the applied force.

Furthermore, the invention relates to a construction element for a toy construction set. The building element includes a cylindrical plastic bushing having an internal thread for receiving a screw having a corresponding threaded portion. The bushing defines at least one groove extending along the threaded portion.

If the screw is loaded with a certain amount, the grooved portion of the bush bends outward, thereby loosening the screw from the bush with the threaded hole. The bushing is usually produced from plastic by injection molding and is subsequently assembled with the main body of the building element. It is often advantageous for the bushing to be an integral part of the body if the groove is oriented in the same direction as the core is stripped.

The bushing of the building element often has several longitudinal grooves which have the same axial extent and which divide the bushing into several elastic parts in segments. Generally speaking, it is easier to dimension the bushing to obtain the desired elastic properties if several elastic beams are formed. The above also applies to the screw when the screw forms several grooves. The respective direction-independent compression and expansion of the screw and the bushing are most easily achieved if the grooves are arranged equidistantly around the circumference.

Brief description of the drawings

The present invention will be described more fully below in conjunction with preferred embodiment and with reference to accompanying drawing, in the accompanying drawing:

Figures 1a and 1b are schematic side views of two building elements with a screw and a bushing according to the present invention;

Figure 2 is an enlarged side view of the slotted screw shown in Figure 1a;

Fig. 3 is a longitudinal sectional view of the screw shown in Fig. 2;

Figure 4 is a partial sectional view of another embodiment of a screw according to the present invention and a building element in a connected position;

Figure 5 is a cross-sectional view of the connection shown along line V-V in Figure 4;

FIG. 6 is a sectional view of a preferred embodiment of a bushing in a building element according to the invention, said bushing being shown in a connection corresponding to FIG. 5 .

Figure 7 is a cross-sectional view of another embodiment of a bushing in a building element according to the invention, said bushing being shown in connection corresponding to Figure 5; and

Figure 8 is a cross-sectional view of yet another embodiment of a bushing having axial termination grooves in accordance with the present invention.

Detailed Description of the Recommended Embodiment

Figures 1a and 1b show two building elements 10 and 11, respectively, which are sold under the trademark "DUPL0 TOOL0® ^" . Some possibilities of using these elements are described in patent EP-A-0 612 262, from which the building element 10 also appears to have a rotary mounting insert in the form of a plastic screw 12 . The screw 12 is mounted slidingly so that it can move axially between two stops. Screw in the screw (included in the building installation) with a tool suitable for the purpose to secure the joint when they are connected to the upper side by the coupling studs of the building elements and by a complementary coupling mechanism or This coupling is achieved when the groove is connected to the underside.

The screw 12 itself is shown alone in FIGS. 2 and 3 , ie it has been removed from the building element 10 shown in FIG. 1 a. This screw 12 is made as a hollow plastic part, and has a main body part 13, and this main body part 13 has two circular projections 18 and 19, and these two circular projections 18 and 19 serve as above-mentioned screw. Used as a stopper for axial displacement. The screw portion 14 is integral with the body portion 13 and it has an external thread 16 . In a preferred embodiment of the invention, the screw is unique in that it has an axially extending slot 17 .

The illustrated embodiment actually comprises two grooves 17 extending in the axial direction of the screw and meeting in the blunt bottom end 20 of the screw member. What is important to the invention is that the groove extends radially along the entire threaded portion which engages a corresponding threaded portion on a bushing or a threaded hole.

It will be seen from Fig. 3 that the main body portion 13 forms a cavity 15 which is open at the end of the screw and adapted to accommodate and hold the pointed portion of the tool so that the screw follows the screw. Tool turns.

Fig. 4 shows the screw of Figs. 2 and 3 screwed into the bushing 20 in the upper side of the building element 11 shown in Fig. 1b. The bush 20 has an internal thread 21 cooperating with the thread 16 of the screw. The inventors have found that this is particularly suitable when the cooperating threaded parts have a relatively large pitch and few turns. In a particularly suitable embodiment of the invention, the screw has slightly more than one turn and the bush has slightly less than one turn of thread. Thus, when the beam formed by the slotting of the rod 13 bends or flexes inwardly, the actual turns of the screw must just pass through the corresponding turns on the bushing.

It should also be noted that it may be advantageous that the cross-section of the coil is circular, since otherwise significant wear would occur on the thread if separation is repeated. However, even if the coil has a triangular cross-section, and even if there are several turns, the invention will work well as long as the threaded portion is mounted with the necessary elasticity.

When a force is applied to the screw in direction A as shown in FIG. 4, an inversion point 22 will occur, making the screw an inwardly swinging beam, indicated by arrow a. The coils 16 , 21 can thus pass each other in the region 23 .

Fig. 5 shows another embodiment of a screw according to the present invention, which Fig. 5 shows a cross-section corresponding to a part taken along line V-V in Fig. 4 . This thread differs in that its screw 13 has three grooves 17 equidistantly spaced around the circumference. Three substantially uniform beams are thus formed on which the threaded portions 16 are arranged. The bush 11 having the internally threaded portion 21 corresponds to the bush shown in FIG. 4 .

Figure 6 is a cross-sectional view of yet another embodiment of the present invention, where the bush 11 forms two longitudinal grooves 24, which ensure that the parts of the bush 11 on which the threaded portion 21 is provided can be bent outwards or deflect, thus allowing the screw to be disengaged in the same manner as described with respect to FIG. 4 .

As in Figure 6, Figure 7 shows a connection, here the bushing is provided with grooves 24, in this embodiment three grooves 24 equidistantly arranged. Figure 8 shows a longitudinal section of the bush 11, from which it will be seen that the groove 24 does not necessarily extend directly through the bush, but may terminate in a bridge 25 which nevertheless provides the necessary flexibility.

The torque required to separate the threaded sections is not determined by the overlap of the threads (ie the displacement required for the turns to pass each other) and the number of turns. The ease with which displacement is possible depends on the elastic properties of the beam formed in the screw or bushing. That is, these properties depend on the wall thickness, the choice of material, the width in the circumferential direction, the length and position of the grooves in relation to the threaded portion, and on whether the grooves extend axially or are helical. Therefore, nothing prevents the groove from extending in the longitudinal direction, except, for example, with a pitch opposite to the direction of the helix.

The invention has above described a bushing; and as long as it is a slotted screw, it can be used within the scope of the invention in a solid piece having a hole threaded which is exactly Threaded openings required.

When the threaded portion has two radially positioned longitudinal grooves, it may in some cases be advantageous to interrupt or cancel the turn in the region offset by about a quarter of a turn from the grooves. Both the screw and the bushing are preferably made of plastic. Such as ABS resin, HI-POM or a plastic with similar properties.

Claims (10)

1. A toy construction device comprising a screw having a hollow plastic rod forming a threaded portion on the outside, and a building element having a plastic bushing with a corresponding internally threaded portion, characterized in that , the bush or screw forms at least one groove along its length, said groove extending along the threaded portion. 2. Toy construction apparatus according to claim 1, characterized in that the bush and/or screw form several longitudinal grooves having the same axial extent and dividing the screw and/or bush into Segments are divided into several elastic sections. 3. A screw for toy construction set comprising a hollow plastic rod the outside of which forms a threaded portion which fits into a hole having a corresponding threaded portion on another component contained in the toy construction set, The screw is characterized in that along a portion of its length at least one groove is formed, said groove extending through the threaded portion. 4. Screw according to claim 3, characterized in that the screw is formed with several longitudinal grooves having the same axial extent and dividing the screw segmentally into several elastic parts. 5. Screw according to claim 3 or 4, characterized in that the screw rod has two grooves, thus making the elastic part semi-cylindrical. 6. The screw according to claim 3 or 4, characterized in that the screw rod has three equidistantly arranged grooves in the circumferential direction. 7. A building element for a toy construction device comprising a cylindrical plastic bushing having an internally threaded portion for receiving a screw having a corresponding threaded portion, characterized in that the bushing is along A portion of its length forms at least one slot extending through the threaded portion. 8. The building element as claimed in claim 7, characterized in that the bushing forms several longitudinal grooves having the same axial extent and that the bushing is segmented into several elastic parts. 9. A building element as claimed in claim 7 or 8, characterized in that the bushing has two grooves, thus making the elastic part semi-cylindrical. 10. A building element as claimed in claim 7 or 8, characterized in that the bushing has three equally spaced grooves in the circumferential direction.

Images