BOLTING DEVICE

Abstract: This invention relates to a fastener which is inserted into round holes (6, 7) bored on members (3, 4) to be fastened and fastens them (3, 4) together by clamping. A projection (2) to be inserted into the gap between the holes (6, 7) and the shank of a bolt (1) is formed at part of the shank of the bolt (1) or part of the seat surface of a nut (5) so that the projection (2) operates as a means for preventing the rotation of one of the bolt (1) and the nut (5) when the other is turned by a wrench or the like.

Description: The present invention relates to a bolting device having a function of preventing a comnon rotation. A bolting device, in which a noncircular hole is formed in a member to be screwed up and a bolt is provided with an engaging portion to be engaged with a corner portion and the like of the noncircular hole to prevent a common rotation, has been known. In the method of forming the noncircular hole in the member to be screwed up the hole is not easily processed and the punching process by means of a press can not be adopted in many cases. In general, a hole, through which a bolt is inserted, is opened by means of a drill in almost all cases. However, the hole, which can be opened by means of the drill, is circular, so that, even though the bolt is provided with the engaging portion formed in the body thereof, the engaging portion is not engaged with the hole, whereby the common rotation of the bolt cannot be prevented. Therefore, a nut has had to be screwed up by rotating it with fixing a head of the bolt by means of a spanner. This operation has been remarkably dangerous and difficult in an unstable building field, a place where merely one hand can be used and the like. US-A-4266591 discloses a bolting device for insertion through circular holes extending through members to be bolted to each other from opposite surfaces of said members. The bolting device includes a shaft snugly fitting within those circular holes. The shaft carries a threaded pin which is eccentric to the shaft axis. A nut is threaded onto the pin to complete bolting of the two members. DE-C-913838 discloses a bolting device intended to be secured in a blind hole. This bolting device has a threaded bolt body on which a nut is screwed. The bolt body is inserted into the blind hole and carries an eccentric pin and a clamping part. The eccentric pin is urged by the clamping part against the wall of the blind hole on rotation of the bolt body. GB-A-30141/1910 discloses a nut lock for use with a nut screwed onto a bolt which passes through circular holes extending through members to be bolted to each other from opposite surfaces of the members. The bolt head and the nut engage the opposite surfaces of the members. A washer is fitted over the bolt head and rests against the nut and the external surface of the member adjacent to the nut. The washer carries a projection which extends into the circular hole in the member adjacent to the nut between the side of that circular hole and the bolt body. It is an object of the present invention to provide a bolting device capable of preventing a common rotation which can be used in a circular hole. According to one aspect of the present invention, there is provided a bolting device for insertion through circular holes extending through members to be bolted to each other from opposite surfaces of said members, said bolting device comprising: a bolt head; a bolt body; a nut; and a convex portion rigid with and extending along said bolt body, said convex portion making said bolt body eccentric towards one side of said circular hole when said bolt body is inserted in said circular hole, said convex portion being located radially between the bolt body and said side of said circular hole, said convex portion having a height larger than the difference between said radius of said circular hole and the radius of said bolt body passing through said circular hole but smaller than two times said difference and having a relatively short circumferential length, whereby said convex portion prevents said bolt body from rotating with said nut after a) said bolt head and said nut contact respective opposite surfaces of said members, b) said convex portion contacts an inside surface of said circular hole and c) a point on said bolt body contacts said inside surface of said circular hole in that plane transverse to the bolt axis in which the convex portion contacts the inside surface of said circular hole to bolt said members to each other. According to another aspect of the present invention, there is provided a bolting device for insertion through circular holes extending through members to be bolted to each other from opposite surfaces of said members, said bolting device comprising: a bolt head, a bolt body and a nut; and a washer having a convex portion for insertion into a gap between said circular hole and said bolt body, said convex portion making said bolt body eccentric towards one side of said circular hole when said bolt body is inserted in said circular hole, and an engaging portion for engagement a) at one surface with said bolt head and b) at an opposite surface with one of said opposite surfaces of said members adjacent said bolt head, said engaging portion having an extension extending in one axial direction on assembly of the washer on the bolt body, said convex portion extending in an axial direction opposite to said extension of said engaging portion which extension is in engagement with a seat surface on said bolt head, said convex portion being located radially between the bolt body and said side of said circular hole, said convex portion having a height larger than the difference between said radius of said circular hole and the radius of said bolt body passing through said circular hole but smaller than two times said difference and having a relatively short circumferential length, whereby said convex portion prevents said bolt body from rotating with said nut after a) said bolt head and said nut contact respective opposite surfaces of said members, b) said convex portion contacts an inside surface of said circular hole and c) a point on said bolt body contacts said inside surface of said circular hole in that plane transverse to the bolt axis in which the convex portion contacts the inside surface of said circular hole to bolt said members to each other. Embodiments of the present invention will now be described with reference to the accompanying drawings, of which:- Fig. 1 is a cross-sectional plan view showing a relation between a bolt and a hole aiming at the description of a principle for preventing the common rotation in the first embodiment of the invention; Fig. 2 is a longitudinally sectioned side view of Fig. 1; Figs. 3 to 8 are side views and bottom views showing the bolt according to other preferred variants of the first embodiment of the invention; Fig. 9 is a side view showing another preferred embodiment of the bolt according to the first embodiment of the invention; Figs. 10 to 13 are side views and cross sections showing additionally other preferred variants of the bolt according to the first embodiment of the invention; Fig. 14 is a longitudinally sectioned side view showing an example of a second embodiment of the invention; Fig. 15 is a cross-sectional side view showing a relation between a bolt and a hole aiming at the description of a principle for preventing the common rotation in a third embodiment of the invention; Fig. 16 is a longitudinally sectioned side view of Fig. 15; Fig. 17 is a cross-sectional plan view describing a principle for preventing the common rotation in a fourth embodiment of the invention; Figs. 18 to 22 are perspective views showing other preferred variants of a wedge member; Fig. 23 is a side view of the bolt showing one example for supporting the wedge member on the bolt; and Fig. 24 is a longitudinally sectioned side view showing the combination of the wedge, a washer with a convex portion and the conventional bolt. At first, the common-rotation preventing operation of the bolt in the first embodiment of the invention will be below described. The common rotation of the bolt is dependent upon magnitudes of frictional resistance of a seat surface (F) and a screw portion (G) of a nut in Fig. 2. If the frictional resistance of the seat surface (F) is larger than that of the screw portion (G), the common rotation of the bolt can be prevented. In general, there is a gap between the bolt and the hole. It is an object of the first embodiment to prevent the common rotation by providing a convex portion having a suitable dimension in the above described gap. Referring now to Fig. 1, a bolt (1) is made eccentric toward one side of a hole (6) due to a convex portion (2). Here, provided that a center of the hole (6) is (X) and a center of the bolt is (Y), the bolt cannot be rotated with the point (Y) as a center by suitably selecting a height of the convex portion (2), whereby also the point (Y) moves with the rotation of the bolt. By height of the convex portion is meant its radial dimension. The convex portion has a height larger than a difference between a radius of a hole opened in a member to be screwed up and a radius of a body of the bolt but smaller than 2 times this difference is formed in a part of the body of the bolt (1). Upon applying a force rotating the bolt (1) by the common rotation under this condition, the convex portion (2) is engaged with an inner wall of the hole (6) not to be rotated. Upon further applying a force to rotate the bolt (1), the center (Y) of the bolt is moved to (Y'), a point of contact (P) of the convex portion and the inner wall to (P') and a point of contact (Q) of the bolt (1) and the inner wall to (Q') due to the convex portion (2) while sliding. Thus, the center (Y) of the bolt (1) is rotated around the center (X) of the hole (6) with rotating on its own axis. On the other hand, as shown in Fig. 2, on a seat surface (F) of a head of the bolt (1) the center (Y) of the bolt (1) is moved sideways, so that also the seat surface (F) is not rotated with (Y) as a center but moved sideways. Accordingly, the seat surface (F) of the bolt (1) is slid on an area larger than it, so that also the frictional resistance is increased in comparison with that in the case where the center (Y) is not moved. In addition, if a nut is strongly screwed up, also the frictional resistance of the seat surface (F) is increased. Besides, also a frictional resistance between the convex portion (2) and the inner wall of the hole (6) is increased due to this seat surface (F) which is difficult to move. Accordingly, however strongly the nut may be screwed up, the common rotation is not brought about It is understood that, as above described, since the frictional resistance on a side preventing the common rotation includes also the frictional resistances of the points P, Q in addition to the frictional resistance of the seat surface (F) of which sliding area has been increased, it is considerably increased in comparison with that in the case where the conventional bolt is used. On the other hand, since the frictional resistance in the screw portion (G) is same as that in the conventional bolt, the frictional resistance on the side preventing the common rotation is always relatively larger, whereby the common rotation can be prevented. The operation in the second embodiment is same as that in the first embodiment. According to the third embodiment, as shown in Fig. 15, the bolt (1) intends to rotate within a larger hole (6a) with a center (X1) of the hole (6a) as a center under an eccentrical condition due to the existence of the convex portion (2) but a member (4) to be screwed up provided with a smaller hole (6b) formed therein prevents the above described eccentrical rotation of the bolt (1). That is to say, since the smaller hole (6b) has a diameter nearly same one as that of the body of the bolt (1), a center (X2) of the smaller hole (6b) is almost concentric with the center (Y) of the bolt (1). Accordingly, in order to move the center (Y) of the bolt (1) to (Y') by the eccentrical rotation, the member (4) to be screwed up provided with the smaller hole (6b) formed therein must be slid relatively to the member (3) to be screwed up provided with the larger hole (6a) formed therein, which requires a large force. As a result, the common rotation of the bolt (1) can be prevented. Accordingly, if the height of the convex portion (2) is larger than 2 times a difference between the radius of the smaller hole (6b) and the radius of the body of the bolt by the slightest degree, the common rotation can be prevented. According to the fourth embodiment, as shown in Fig. 17, when the bolt (1) provided with the convex portion (2) intends to rotate within the hole (6), a wedge member (9) is fitted into a gap between the body of the bolt (1) and the hole (6) at a position opposite to the convex portion (2) to prevent the comnon rotation of the bolt (1). In this case, if a length from a point of contact of the convex portion (2) of the bolt (1) and the hole (6) to a point of contact of the wedge member (9) and the hole (6) on a line extending through the center of the bolt (1) is larger than the diameter of the hole (6), the wedge is effected. Accordingly, the height of the convex portion (2) may be smaller than that in the first embodiment. According to the fifth embodiment, the wedge member is adapted to act in both the regular rotation and the opposite rotation of the bolt, whereby not only the common rotation of the bolt when screwed up but also that rotated in the loosening direction can be prevented. Fig. 1 is a cross sectional plan view showing a relation of a bolt and a hole aiming at the description of a principle for preventing the common rotation in the first invention and Fig. 2 is a longitudinally sectioned side view of Fig. 1. Referring to Figs. 1, 2, reference numeral (1) designates a bolt, reference numeral (2) designating a convex portion, reference numerals (3), (4) designating members to be screwed up, reference numeral (5) designating a nut, and reference numerals (6), (7) designating circular holes. A height (h) of the above described convex portion (2) can be optionally selected within a range from a value larger than a difference between a radius (rl) of the holes (6), (7) and a radius (r2) of a body of the bolt (1) to a value smaller than 2 times said difference. That is to say, (r1 - r2) < h < 2 (r1 - r2). It is the reason of the above described selection that if the height of the convex portion (2) is smaller than (r1 - r2), the convex portion (2) is rotated without being brought into ccntact with the inner wall of the holes (6), (7) when the center (Y) of the bolt is lain on the center (X) of the hole, whereby the common rotation can not be prevented while if the height of the convex portion (2) is larger than 2 (r1 - r2), the bolt (1) can not be inserted into the holes (6), (7). In the preferred embodiments shown in Figs. 3, 4, an eccentric cam-shaped convex portion (2) is formed in a portion in the vicinity of a head of the bolt of a body (1a) of a bolt (1). In the preferred embodiments shown in Figs. 5, 6, a projection (2a), which is inclined toward a pointed end of a bolt (reduced in height), is added to a part in the vicinity of a head portion of a body. This projection (2a) is drawn into a hole with rubbing an inner wall of the hole to gradually increasing a resistance when the bolt (1) is drawn into the hole (6) by means of a nut (5). Accordingly, the bolt is gradually transferred from a first condition that it is lightly fixed in the hole to a condition that it is strongly pressed against the wall surface to gradually increase a frictional resistance at a point of contact of the bolt and the inner wall. Moreover, a seat surface (F) is stuck to a surface of a member (3) to be screwed up with a progress of the screwing-up operation, so that also the frictional resistance is gradually increased to prevent the common rotation of the bolt and the nut. The regulating function is brought about in the combination of the diameter of the hole and the diameter of the bolt to some extent in addition to an operation of increasing a resistance for preventing the common rotation by giving said inclination to the projection (2) shown in Figs. 1, 3. Referring to Figs. 7, 8, a bolt (1) is opened in a head portion thereof and a pin (2b) is set up in the opening to form a convex portion. It is natural that the convex portion must be housed in an opening formed in a member to be screwed up, so that both a height (h) and a length (L) of the convex portion are dependent upon a size of the hole. In addition, this pin (2b) may be tapered in the direction of length like the convex portion (2a) shown in Fig. 5. Fig. 9 shows a preferred embodiment wherein a separate metallic piece is spliced to a part in the vicinity of a head portion of a body (1a) of a bolt (1) by the welding and the like to form a convex portion (2). In addition, in the case of a plastic bolt or a bolt formed of ceramics, a plastic piece or a ceramic piece having the same one hardness as the bolt or more is spliced to the bolt. In the preferred embodiments shown in Figs. 10, 11, a piano wire, which is obliquely cut at both ends, is welded to one side of a body (la) of a bolt (1) to form a convex portion (2). This convex portion (2) is sharp at both ends in the direction of rotation of the bolt (1), so that the sharp ends are stuck into an inner wall surface of a hole (6), whereby the resistance to the common rotation can be increased. Figs. 12, 13 show other preferred embodiments wherein a concave portion (1b) is formed in a body portion (1a) of a bolt (1) and a separate metallic piece and the like are spliced to this concave portion (1b) to form a convex portion (2). The convex portion (2) may have various kinds of shape in addition to the above described ones. In addition, in the case where the separate member is spliced to the concave portion of the bolt (1), its material can be optionally selected. Referring to Fig. 14 showing a preferred embodiment of the second embodiment, a washer (8) is provided with a convex portion (2) extending integrally therewith in one axial direction in a part of a hole thereof and a square hole-shaped engaging portion (8a) bent in the other axial direction formed in an outer circumferential portion thereof. A head of the conventional bolt (1), which is not provided with a convex portion (2), is engaged with the above described engaging portion (8a) to integrally rotate the washer (8) and the bolt (1), whereby achieving the similar common rotation-preventing effect to that in the case where the bolt (1) is provided with the convex portion (2). Figs. 15, 16 is a cross sectional plan view and a longitudinally sectioned side view showing a relation between a bolt and a hole aiming at the description of a principle for preventing the common rotation in the third invention, respectively. Referring to Figs. 15, 16, one of members (3), (4) to be screwed up is provided with a small hole (6b) having a diameter nearly equal to a diameter of a body of a bolt (1) formed therein and the other is provided with a larger hole (6a) formed therein so that a convex portion (2) may be engaged with the larger hole (6a). Since an operation in this case has been already described, it is omitted. In addition, the convex portion (2) may be combined with the washer (8) shown in Fig. 13. Fig. 17 is a cross sectional plan view showing a relation between a bolt and a hole aiming at the description of a principle for preventing the common rotation in the fourth invention. Referring to Fig. 17, a bolt (1) provided with a convex portion (2) and a wedge member (9) are used in combination. In this case, when the bolt (1) provided with the convex portion (2) intends to rotate within a hole (6), the wedge member (9) is bitten into a gap between a body of the bolt (1) and the hole (6) at a position opposite to the convex portion (2) to prevent the common rotation of the bolt (1). The above described wedge member (9) is symmetrically formed so as to bite into both the regular rotation and the opposite rotation of the bolt (1). Various kinds of preferred embodiment of the wedge member (9) are shown in Figs. 18 to 22, in which Fig. 18 shows the case where the wedge member (9) is formed in a washer (10), Fig. 19 showing the case where the wedge members (9), (9) are formed at both ends of a belt-shaped metallic plate (11) provided with a window (11a) formed therein, Fig. 20 showing the case where the similar configuration is formed of a metallic wire (12) such as a wire, Fig. 21 showing the case where in order to connect both wedge members (9), (9) to each other on a side opposite to the convex portion (2), they are connected to each other by means of a plate-like bridge member (13) having a reduced wall-thickness on pointed end sides where the wall-thickness of the wedge members (9), (9) is reduced, and Fig. 22 showing the case where a metallic wire (14) is bent at both ends thereof and rolled so that the pointed end sides thereof may be reduced in wall-thickness to form the wedge members (9), (9). A length of the member for connecting the wedge members (9), (9) shown in Figs. 19 to 22 to each other is selected at 1/2 times a peripheral length of the body of the bolt (1) or more and said member is bent in an arched shape so as to be idly engaged with the body of the bolt (1). In this case, if the convex portion (2) of the bolt (1) is slightly separated from the head, as shown in Fig. 23, the connecting member can be supported between the convex portion (2) and the head and the window (11a) can be inserted into the convex portion (2) to support the connecting member. In addition, a flange for engaging the wedge members (9), (9) with a peripheral edge of a hole (6) to support them may be bent. In this case, it is desired that a separate washer provided with a hole having a diameter slightly larger than an outside diameter of the flange or washer (10) and having a thickness larger than that of the flange or washer (10) is used together similarly to the washer (10) shown in Fig. 18 to make the wedge members (9), (9) independent of the movement of the bolt. Fig. 24 shows the case where the washer (8) shown in Fig. 14 and the wedge members (9), (9) shown in Fig. 21 are used in combination with the conventional bolt (1). The above described wedge members (9), (9) may have a diameter larger than that of the hole (6) to be self-sustained in the hole (6) by an elastic action. In addition, the above described wedge members (9), (9) can be formed as separate members to bite into the bolt (1) from both directions of the regular rotation and the opposite rotation of the bolt (1), whereby fixing in the hole (6). Since the wedge members (9), (9) of this type can position and fix the bolt (1) in the hole (6), they can be used also in means for positioning and fixing a zero point of a knob in an assembly process of a variable resistor in acoustic instruments and the like. The above described wedge members (9), (9) can be formed of plastics, ceramics and other suitable materials without limiting to metallic materials.

Claims: A bolting device for insertion through circular holes (6, 7) extending through members (3, 4) to be bolted to each other from opposite surfaces of said members, said bolting device comprising: a bolt head; a bolt body; a nut (5); and a convex portion (2) rigid with and extending along said bolt body, said convex portion (2) making said bolt body eccentric towards one side of said circular hole (6) when said bolt body is inserted in said circular hole (6), said convex portion (2) being located radially between the bolt body and said side of said circular hole (6), said convex portion (2) having a height larger than the difference between said radius of said circular hole (6) and the radius of said bolt body passing through said circular hole (6) but smaller than two times said difference and having a relatively short circumferential length, whereby said convex portion prevents said bolt body from rotating with said nut (5) after a) said bolt head and said nut (5) contact respective opposite surfaces of said members (3, 4), b) said convex portion (2) contacts an inside surface of said circular hole (6) and c) a point (Q) on said bolt body contacts said inside surface of said circular hole (6) in that plane transverse to the bolt axis in which the convex portion (2) contacts the inside surface of said circular hole (6) to bolt said members (3, 4) to each other. A bolting device for insertion through circular holes (6, 7) extending through members (3, 4) to be bolted to each other from opposite surfaces of said members, said bolting device comprising: a bolt head, a bolt body and a nut (5); and a washer (8) having a convex portion (2) for insertion into a gap between said circular hole (6) and said bolt body, said convex portion (2) making said bolt body eccentric towards one side of said circular hole (6) when said bolt body is inserted in said circular hole (6), and an engaging portion for engagement a) at one surface with said bolt head and b) at an opposite surface with one of said opposite surfaces of said members adjacent said bolt head, said engaging portion (2) having an extension (8a) extending in one axial direction on assembly of the washer on the bolt body, said convex portion (2) extending in an axial direction opposite to said extension of said engaging portion which extension is in engagement with a seat surface on said bolt head, said convex portion (2) being located radially between the bolt body and said side of said circular hole (6), said convex portion (2) having a height larger than the difference between said radius of said circular hole (6) and the radius of said bolt body passing through said circular hole (6) but smaller than two times said difference and having a relatively short circumferential length, whereby said convex portion (2) prevents said bolt body from rotating with said nut (5) after a) said bolt head and said nut (5) contact respective opposite surfaces of said members (3, 4), b) said convex portion (2) contacts an inside surface of said circular hole and c) a point on said bolt body contacts said inside surface of said circular hole in that plane transverse to the bolt axis in which the convex portion (2) contacts the inside surface of said circular hole to bolt said members (3, 4) to each other.

Inventors: ISHIDA EISUKE, ISHIDA, EISUKE
Applicants: ISHIDA EISUKE, ISHIDA, EISUKE
Application year: 1989
Main classification: F16B35
IPC codes: F16B35, F16B39, F16B33, F16B2