DE202021003296U1 - Safety precautions on a one-handed bolt to reduce accidental loosening - Google Patents

Abstract

An annular form- and force-elastic component inserted in a clamping bolt ensures, through its at least partially elastic deformation by means of the resulting compressive force, increased static friction as a rotary brake as well as positive and non-positive locking, the function of the clamping bolt and secures it against unintentional twisting and loosening, with additional toothing on the Underside ensures increased resistance against unintentional loosening due to its deformation in the state of tension.

Description

A myriad of detachable connections are made and used. The best known is the screw-nut connection. Securing against unintentional loosening and loosening plays a crucial role in this system. To this end, a large number of different suitable components were developed for almost every application.

The handling of the known safety systems usually requires the use of both hands for assembly and disassembly. A bent additional locking plate or at least temporarily clamping tools can also be representative of a second hand. As a rule, this backup means additional equipment and often additional tools or precautions.

When using clamping bolts, the aspect of securing the clamping position is of eminent importance in almost every functional situation. It is often the decisive aspect of using these bolts.
The invention is intended to reduce the assembly/disassembly effort. One hand is often required to hold the workpiece or an additional device, especially in special industries, for example with welding and assembly tables or clamping tables of machine tools. Only the second hand is free to mount a clamping bolt. Quality-oriented production begins with qualified positioning and clamping of the workpieces. The functions of this clamping bolt according to the invention support the desire for a high degree of safety and the desire for so-called one-person jobs. Often a second person to help is simply not available.

The geometric structure of the clamping bolt securing.

Essentially, the functional structure corresponds to the geometry according to Pat. 10 2018 126 997.8 . In addition, and another advantageous feature of this solution according to the invention, is the securing of the clamping bolt against unintentional twisting or, above all, unintentional loosening. For this purpose, the clamping bolt is largely contoured as described in the above patent specification. In addition, a permanently elastic molded ring (8) with a cylindrical contour is inserted in a circular cylindrical recess in the clamping bolt (1). When mounting the clamping bolt (1), this form ring (8) is compressed somewhat in its longitudinal extension. It arises in the ring (8) form tension. This form stress generates increased static friction when in contact, i.e. pressing, with adjacent components (13). In addition, to increase the safety of the clamping system, there is a projection (3) pointing towards the top of the bolt at the end of the hook-shaped construction (2). In cooperation with the surrounding contour, this projection (3) forms a hook-shaped structure. One could now assume that a metallic compression spring could fulfill the same task. Due to the cylindrical dimensional stability, this spring could only be brought into position with difficulty or not at all over the lower contours (2; 3; 14) of the clamping bolt. In order to position the elastic clamping ring, it must also be possible to temporarily deform its outer contours in all three-dimensional axes. A metallic spring cannot do that. A metallic spring can break unnoticed during use and thus not fulfill its task. In addition, the chosen solution of the dimensionally stable and permanently elastic clamping ring is significantly cheaper.

The form ring, which is designed in its basic form as a cylindrical circular ring, can also be designed with teeth on the top and bottom. These teeth (27), as an example in 10 shown, can be varied geometrically. in 10 In the embodiment shown as an example, the teeth are pressed together when in use and press into the environment and prevent the bolts from being loosened unintentionally. In a geometrically simplest form, the circular ring can also have a round cross section.

In a further advantageous geometric design of the clamping bolt and, matching it, a bevel (22) on an edge (2) of the clamping bolt (1) and a chamfer (20) in the lower area of the bores, mainly on the projections (7). Another embodiment has a smaller diameter (28) at the top than the diameter (4) of the annular groove of the bolt. And in its lower part a larger diameter (29) than the diameter of the annular groove (4) of the bolt. This execution in 11 improves handling when locking and unlocking the bolt.

The aim of this special contouring is to increase the contact surfaces between the clamping pin and the area around the hole. These force-transmitting contact and clamping surfaces are increased by about 20%, for example, at an angle of 30°. This means that the resulting static friction increases by this amount. Or, with the same tensile force of the bolt, the specific material pressure drops by this amount. Due to the chamfering of the edges, a parallelogram of forces is created in this area. This is a part of the axisymmetric tensile forces of the Bol zens advantageously diverted. The advantageous details of the power diversion are shown in the drawing. This reduction in the specific pressure and shear load that can be achieved in this way opens up, for example, a reduction in the strength properties of the bore material. This means that higher-strength aluminum can be used in the lower area of the bores for the overhangs instead of the steel that would otherwise be required. This makes it possible, for example, to produce a worktop (13) with all geometric contours (1; 6; 7) from just one optimally suited material and to use it as intended. For stainless steel processors, this design means, for example, a workbench with aluminum work surfaces, cost savings and the security of a consistent so-called black and white separation.

The function

The functional sequence for the intended use as a safety clamping bolt. The bolt (1) is inserted with one hand from the cylindrical end of the bore into a correspondingly shaped bore, consisting of a cylindrical contour (1) and a cloverleaf-shaped contour (6; 7) in the broadest sense. If it cannot be inserted immediately to maximum depth, it must be turned back and forth a little in order to fully immerse it. Then the elastic form ring (8) of the clamping bolt sits with its underside on the projections (7) of the cloverleaf-shaped contour. With a slight pressing (16) of the clamping bolt in the longitudinal axis, the elastic form ring (8) is compressed by an amount. At the same time, the clamping pin (1) is turned to the right until you feel a stop (17). During this movement process (17), the hook-shaped projection (3) moves past at a sufficient distance from the cloverleaf-shaped projections (7) of the bore system. After releasing the clamping bolt (1), the form force of the elastic clamping ring ( 3 ) the top of the hook-shaped contour (2; 3) against the projections (7) of the bore system. The apex (3) of the projection is now above the lower edges of the projections (7). The bolt (1) is thus locked. It is secured against unintentional loosening. The amount of clamping force can be varied by selecting an appropriate material for the elastic clamping ring (8). The clamping bolt (1) is then non-positively and positively connected to the clamping table 12; 13) connected. Other functions, such as clamping components and tools to the clamping table, are carried out in the usual way as described in Pat. 10 2018 126 997.8 described.

The design of the clamping bolt (1) according to the invention offers a further advantage. When the clamping nut (10) is loosened by turning it to the left, the bolt (1) according to the invention remains securely locked.

Only by pressing (16) the clamping bolt (1) in its longitudinal direction on the clamping table (12; 13) is the bolt (1) unlocked and removed by turning left to the stop (14) and then pulling.

Enumeration of the reference numbers

1

bolt body

2

hook formations of the lateral surface

3

overhang of the hook formations

4

annular groove

5

bolt floor

6

Drilling system in the table top of a clamping table

7

Overhangs in the drilling system of the tabletop

8th

elastic form ring

9

Directions of deformation of the elastic mold ring

10

clamping nut

11

Central axis, axis of symmetry

12

Table top with cylindrical bore

13

Part of the tabletop with butterfly-shaped projections in the hole

14

Lateral and rotary stop

15

Inner contour of a recess in a tabletop that fits the clamping bolt

16

manual one-handed insertion of the bolt

17

manual one-handed turning of the bolt to the right up to the stop

18

spring back and engage the clamping bolt

19

Hatching for sectional view

20

Bevel at the bottom of the hole

21

force diversion

22

bevel on the bolt

23

any circular plate section

24

Hatching for sectional view

25

Chamfer on the clamping bolt

26

bolt thread

27

Perforation of the elastic clamping ring

28

diameter less than 4 in 1

29

larger diameter than diameter 4 in 1

character list

• 1 shows a cylindrical clamping bolt (1) with hook-shaped formations (2) on its lower end and projections (3) on the respective upper ends of the formations (2).
• 2 shows enlarged details of the formations (2) with projections (3).
• 3 shows an elastic clamping ring (8) in a plan view and a sectional side view.
• 4 shows a clamping bolt (1) with a nut (10) and an elastic clamping ring (8) in a table bore (12; 13)
• 5 shows a perspective view of a contoured recess (6; 7) in a clamping table, for example, for hooking (16; 17; 18) the clamping bolt (1)
• 6 shows a complete clamping bolt (1) with nut (10) and elastic clamping ring (8) in a transparent perspective view
• 7 shows the sequence of movements in increasing numbers (16; 17; 18) for tightening the bolt (1) in a vector representation.
• 8th shows a central longitudinal section through a clamping bolt with a slanted overhang in front view
• 9 shows a circular exemplary half-section from a worktop with a lower bevel of the bore contour in a perspective view
• 10 shows a half section of a toothed elastic clamping ring as a silhouette in perspective
• 11 shows a half section of a toothed elastic clamping ring with different inner diameters

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• WO 102018126997 [0005, 0009]

Claims (3)

An annular form- and force-elastic component inserted in a clamping bolt ensures, through its at least partially elastic deformation by means of the resulting compressive force, increased static friction as a rotary brake as well as positive and non-positive locking, the function of the clamping bolt and secures it against unintentional twisting and loosening, with additional toothing on the Underside ensures increased resistance against unintentional loosening due to its deformation in the state of tension. Partial bevels on the clamping bolts and butterfly-shaped recesses increase the pressure areas between the two components when clamped and reduce the specific surface pressure. All movements of the clamping bolt for securing and releasing can be carried out with one hand.

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