JP4549334B2 - Pan head device - Google Patents

Description

  The present invention relates to a pan / tilt head device in which, for example, a surveillance camera or the like is suspended from a ceiling positioned on a windshield of a moving body such as a car.

  In the conventional pan head device, in order to firmly fix the camera mounted on the pan head, a fixing and releasing mechanism (mainly a screw) is disposed in the vicinity of the rotating ball shaft (see, for example, JP-A-10-288811). ). FIG. 9 and FIG. 10 show a conventional pan head apparatus described in the above publication.

  9 is a perspective view in which a part of the case main body is broken, and FIG. 10 is a longitudinal sectional view. This pan / tilt head device is provided with a truncated cone-shaped pedestal 121 having a conical surface 122 formed on the upper portion of the cylindrical case body 101, and a belt-shaped tightening mechanism 131 having a handle 141 on the upper portion of the pedestal 121. Is arranged. Further, a spherical ball shaft 111 is placed on top of the tightening mechanism 131. Conical surfaces 132 and 133 are formed on the upper and lower inner surfaces of the ring portion of the tightening mechanism 131, the lower conical surface 133 and the conical surface 122 of the base 121 are in contact with each other, and the upper conical surface 132 is spherical. A ball shaft 111 is on. The upper part of the ball shaft 111 is in contact with the upper inner surface of the case main body 101.

In the above configuration, when the handle 141 is rotated in the fixing direction, the tightening mechanism 131 is tightened inward by the action of the screw shaft 142 of the handle 141, and the ring portion of the tightening mechanism 131 is connected to the ball shaft 111 and the base 121. I will interrupt you. Since the ball shaft 111, the tightening mechanism 131 and the pedestal 121 are arranged in the case body 101 without any gap, the conical surfaces 132 and 133 formed on the upper and lower ends of the tightening mechanism, the conical surface 122 of the pedestal 121, and the ball shaft Due to the inclination vector of 111, the ball shaft 111 is raised and pressed firmly against the upper inner surface of the case body 101, and the ball shaft 111 is fixed to the case body 101.
Japanese Laid-Open Patent Publication No. 10-288811

  However, in the conventional configuration, the ball shaft 111 cannot obtain a sufficient holding force with respect to the case body 101 if the processing accuracy of the parts is poor. For this reason, special machining is required to manufacture the inclined surface, and the parts are expensive. In addition, since the ball shaft 111 is fixed or released by the screw shaft 142 of the handle 141, when installed on a moving body such as a car, there is a problem that the screw is loosened by vibration and the fixing force is reduced.

  The present invention has been made in view of such problems, and an object thereof is to provide a pan head device having a strong fixing force that is strong against vibration.

In order to solve the conventional problem, a pan head device of the present invention includes a ball shaft having a ball portion and a shaft portion, a case main body provided with a ball bearing for holding the ball portion of the ball shaft, A pressing plate capable of pressing the ball shaft against the ball bearing; and a cam for pressing the pressing plate in the direction of the ball shaft by rotating a lever, wherein the ball portion includes an upper ball and a lower ball having different center positions. The cam has a first flat portion and a second flat portion having a distance from the cam rotation center longer than that of the first flat portion, and the cam is rotated by rotating the lever. When the first flat portion of the cam presses the pressing plate, the pressing plate does not press the ball shaft, and by rotating the lever, the second flat portion of the cam presses the pressing plate. When pressing, the push plate pushes the ball shaft. By applying, to the structure of the ball shaft is fixed sandwiched the said ball bearing push plate.

  According to the pan / tilt head device of the present invention, the lever rotation is boosted by the lever principle to push down the push plate, and the cam and the cam contact surface are brought into contact with the flat portion, whereby a large fastening force can be obtained with a small force. It is possible to produce a strong and strong vibration-resistant fixing with one-handed operation.

The best mode for carrying out the present invention will be described below with reference to the drawings. In the present embodiment, a pan head device for fixing a vehicle-mounted monitoring camera in a car will be described as an example. However, the pan head device of the present invention is not limited to a car head device. It can be used in ships, etc., or when the camera is fixed to a pillar or wall of a building, and its application is not limited to a narrow range.
(Embodiment 1)
FIG. 1 shows a component configuration diagram (disassembled perspective view) of a pan head apparatus according to Embodiment 1 of the present invention.

  The casing of the main body of the pan head device is composed of a substantially oval case main body 211 and a lid body 251 that covers the upper portion of the case main body 211. The case main body 211 covers the lid body 251 to form a shallow storage space. It has. The lid 215 is fixed to the case main body 211 with fixing screws 291. A bowl-shaped ball bearing 212 for supporting the ball shaft 201 is formed at the front portion of the case main body 211.

  The ball shaft 201 is composed of a ball portion 203 in which the head of a sphere is cut out and a shaft portion 204 that extends downward from the bottom of the ball portion 203. The ball shaft 201 is rotatably supported by a ball bearing 212 formed on the case main body 211, and the ball portion 203 is formed from above by a ball shaft pressing portion 222 positioned around the circular hole 225 of the pressing plate 221. It is pressed down and fixed to the case body 211. The reason why the head portion of the ball portion 203 is notched is to reduce the thickness of the casing.

  The push plate 221 protrudes with the ring-shaped ball shaft pressing portion 222 having the circular hole 225 as described above, and the inclined portion 226 inclined downward from the rear end edge of the ball shaft pressing portion 222, Further, the cam contact surface 223 protrudes horizontally from the inclined portion 226. The cam contact surface 223 at the rear end of the pressing plate 221 is in a position to contact a cam 231 formed on the lever shaft 241 (hereinafter abbreviated as a cam. Details of the cam will be described later). 223 is pushed down by the cam 231. Further, a screw contact point 224 is provided on the opposite side of the cam contact surface 223 across the tip end portion of the push plate 221, that is, the ball shaft pressing portion 222. The contact point 224 has a triangular piece projecting forward from the ball shaft pressing portion 222, and the piece serves as the contact point 224. Further, reinforcing ribs 227 are formed on both sides of the pressing plate 221. In the present embodiment, the pressing plate 221 is formed by an integral drawing method using a stainless steel plate for a spring.

  The lever 242 is coupled to one end of a lever shaft 241 provided with the cam 231 by a screw (not shown). The rotation of the lever 242 is transmitted from the lever shaft 241 to the cam 231 to rotate the cam 231. The lever shaft 241 is held in a rotatable state by bearings 213 and 253 formed by cutting out the side edges of the case body 211 and the lid body 251 into a semicircular shape.

  The lid body 251 has an adjustment screw hole 252 at a position facing the screw contact point 224, and the adjustment screw 261 is screwed therein. The screw contact point 224 is arranged in a state where it can be pressed downward, loosened, or moved in the vertical direction by the rotation of the adjustment screw 261.

  The mounting bracket 271 is bent in a spoon shape, and a mounting hole 272 is formed at the center of the circular portion at the rear end. Using this mounting hole 272, it is fastened together with the sun visor hook of the vehicle and fixed to the vehicle body (not shown). Further, the whole head is suspended by a fixed screw 281 via a truncated cone-shaped column 282. The operation of the pan / tilt head device according to the embodiment of the present invention configured as described above will be described with reference to FIG.

  FIG. 2 is a cross-sectional view of the pan / tilt head device according to Embodiment 1 of the present invention, and the fixing screws 291 and screw holes are omitted for the sake of explanation. In FIG. 2, the cam 231 is provided with two flat portions, that is, a first flat portion 232 and a second flat portion 233 so as to form an obtuse angle. The distance between the second flat portion 233 and the rotation center of the lever shaft 241 is longer than the distance between the first flat portion 232 and the rotation center of the lever shaft 241.

  In FIG. 2, the cam 231 is located at a loose position, and this cam 231 is in contact with the cam contact surface 223 at the first flat portion 232. At this time, the pressing plate 221 does not press the ball shaft 201, that is, the pressing force is zero. For this reason, the ball shaft 201 supported by the ball bearing 212 can move at a constant angle because the movement of the ball portion 203 is not suppressed by the ball shaft pressing portion 222 of the pressing plate 221. For this reason, the photographing angle of the camera 301 attached to the shaft portion 204 of the ball shaft 201 can be changed.

  Next, when the lever 242 is rotated from the loose position shown in FIG. 2 to the tightening position in the arrow direction, the cam 231 comes into contact with the cam contact surface 223 at the second flat portion 233. Since the second flat portion 233 is farther from the rotation center of the lever shaft 241 than the first flat portion 232, the cam 231 boosts the cam contact surface 223 of the push plate 221 on the basis of this principle, and moves downward. Press down.

  Since the cam contact surface 223 contacts the flat portion of the first flat portion 232 or the second flat portion 233, the cam 231 has a push plate 221 at a position other than the two positions of the loose position and the tightening position. It is pushed back to any position by the reaction force. For this reason, the lever 242 has only two positions, a loose position and a tightening position. Further, since the cam contact surface 223 comes into contact with the flat portion of the cam 231 and a reaction force is applied to the cam 231, the lever 242 is restrained from rotating. Never loosen. The deformation and movement of the abutting object by the cam 231 and the boosting by the lever action are well-known techniques, so the description is omitted here.

  The pushed-down pressing plate 221 has a contact point 224 with which the adjusting screw 261 contacts as a fulcrum, a cam contact surface 223 as a force point, and a ball shaft pressing part 222 as an action point. At the same time as pressing the ball portion 203 of the ball shaft 201, the ball shaft 201 is pressed against the ball bearing 212, and the ball shaft 201 is firmly fixed to the case body 211. In the first embodiment, the lever 242 and the cam 231 are used to boost the lever plate 221 and the lever 242 and the cam 231, respectively. Strong fixation is realized by light operation of 242. As described above, the pan head apparatus of the present invention can loosen and tighten the ball shaft 201 by switching the loose position and the tightening position of the lever.

  In addition, by adjusting the vertical position of the adjustment screw 261 and changing the position where the adjustment screw 261 contacts the screw contact point 224, the position of the fulcrum changes, and the fixing force when the lever 242 is set to the tightening position is increased. Can be adjusted.

  Next, according to the present invention, it will be described with reference to FIG. Even if deviations occur in the diameter of the ball portion 203 of the ball shaft 201, the diameter of the spherical surface of the ball bearing 212, and the diameter of the circular hole 225 of the ball shaft pressing portion 222, the abutting portions of the individual components are in contact with the sphere. Therefore, the positions of the cam contact surface 223 and the cam 231 can be easily corrected by rotating the adjustment screw 261 to move the fulcrum. In the present invention, the loose position and the tightening position are set to two positions. However, it is also possible to apply a pressure to the pressing plate 221 with the adjusting screw 261 so that the ball shaft 201 has a slight friction load at the loose position. Is possible. In addition, in order to prevent the holding force from being deteriorated due to wear or deformation of parts due to long-term use, the adjustment screw 261 can be loosened and the adjustment screw 261 can be rotated to return to the firm fixation.

  FIG. 3 shows another embodiment of the first embodiment. In another embodiment, a rib 214 is formed on the bottom plate of the case body 211 in the vicinity of the rear of the ball shaft 201, and an elastic body 215 made of rubber, sponge, or the like is provided on the upper end of the rib 214. The elastic body 215 lifts the pressing plate 221 upward so that the ball shaft pressing portion 222 of the pressing plate 221 does not contact the ball portion 203 of the ball shaft 201. The elastic body 215 may use a spring instead of rubber or sponge.

  As shown in FIG. 2, the ball shaft 201 can be moved even when the pressing plate 221 does not press the ball shaft 201, that is, when the pressing force is zero. However, the opening edge of the ball shaft pressing portion 222 may be caught in the ball portion 203 of the ball shaft 201 and may not move smoothly. For this reason, as described above, if the pressing plate 221 is lifted by the elastic body 215, the loose position of the lever 242 is between the opening edge of the ball shaft pressing portion 222 and the ball portion 203 of the ball shaft 201. A gap is opened, and the movement of the ball shaft 201 is smooth.

  When the lever 242 is pushed down against the elastic force of the elastic body 215, the ball shaft pressing portion 222 can press the ball portion 203 of the ball shaft 201, and the ball shaft 201 is fixed to the case body 211. The

  FIG. 4 is a use state diagram showing a state in which the surveillance camera 301 is attached to the camera screw 202 of the ball shaft 201 of the pan head apparatus according to Embodiment 1 of the present invention and the lever 242 is operated. In general, on the back of the vehicle-mounted camera, switches for image zooming and image recording start are arranged. According to the present invention, since the lever operating point can be configured at a position where the lever 242 can be operated with the second finger when grasping the back of the camera, aiming at the subject, fixing the pan head, starting shooting A series of actions can be realized with only one hand.

1 and 2, the pressing plate 221 is formed by an integral drawing method using a steel plate. However, the pressing plate 221 is also effective in a molded product by injection molding such as aluminum die-casting. It goes without saying that the same effect can be obtained even if the surface is spherical.
(Embodiment 2)
Embodiment 2 of the present invention will be described below with reference to the drawings. This embodiment will also be described by taking as an example a pan head device for fixing an in-vehicle surveillance camera in a vehicle.

  FIG. 5 shows a component configuration diagram (disassembled perspective view) of the pan head apparatus in the embodiment of the present invention. The pan head apparatus according to the second embodiment includes a casing made up of a case main body 211 and a lid body 251, a push plate 221 having a screw contact point 224, a ball shaft pressing portion 222, and a cam contact surface 223, and a cam 231. The provided lever shaft 241 and lever 242, mounting bracket 271 and adjustment screw 261 have the same configuration as that of the first embodiment, and therefore the same reference numerals in the drawings are used and detailed description thereof is omitted.

  In the second embodiment, the ball shaft 201 is different from the first embodiment. The ball shaft 201 includes a ball portion 203 and a shaft portion 204, and the ball portion 203 integrally forms a lower sphere 203 a centered on the point A and an upper sphere 203 b centered on the point B. The upper sphere 203b and the lower sphere 203a have substantially the same diameter, but the center point A of the lower sphere 203a and the center point B of the upper sphere 203b are on the center axis of the ball axis 201, and the center point B is the center point A. Is located below. Of course, the upper sphere 203b and the lower sphere 203a may have different diameters. Further, the distance between the center point A and the center point B may be wider or narrower than shown in FIG. Further, the upper and lower positions of the center point A and the center point B may be interchanged.

  The ball shaft 201 is supported by a ball bearing 212 formed on the case main body 211 so that the lower ball 203a is rotatable, and the upper ball 203b is pressed by the ball shaft pressing portion 222 of the pressing plate 221 from above. Attached and fixed to the case body 211.

Next, the use state of the above configuration will be described.
In FIG. 6, the cam 231 is located at a loose position, and this cam 231 is in contact with the cam contact surface 223 at the first flat portion 232. At this time, the pressing plate 221 does not press the upper ball 203b of the ball shaft 201, that is, the pressing force is zero. For this reason, the movement of the upper ball 203b is not suppressed by the ball shaft pressing portion 222 of the pressing plate 221, so that the ball shaft 201 can be moved. For this reason, the photographing angle of the camera 301 attached to the shaft portion 204 of the ball shaft 201 can be changed.

  Next, when the lever shaft 241 is rotated from the loose position shown in FIG. 6 to the tightening position in the arrow direction, the cam 231 comes into contact with the cam contact surface 223 at the second flat portion 233. Since the second flat portion 233 is farther from the rotation center of the lever shaft 241 than the first flat portion 232, the cam 231 boosts the cam contact surface 223 of the push plate 221 on the basis of this principle, and moves downward. Press down.

  Since the cam contact surface 223 contacts the flat portion of the first flat portion 232 or the second flat portion 233, the cam 231 has a push plate 221 at a position other than the two positions of the loose position and the tightening position. It is pushed back to any position by the reaction force. For this reason, the lever 242 has only two positions, a loose position and a tightening position. In addition, since the cam contact surface 223 comes into contact with the flat portion of the cam 231 and a reaction force is applied to the cam 231, the lever shaft 241 is restrained from rotating. Will not loosen. This is the same as in the first embodiment.

  The pushed-down pressing plate 221 has a contact point 224 with which the adjusting screw 261 contacts as a fulcrum, a cam contact surface 223 as a force point, and a ball shaft pressing part 222 as an action point. Simultaneously pressing the upper ball 203b, the lower ball 203a of the ball shaft 201 is pressed against the ball bearing 212, and the ball shaft 201 is firmly fixed to the case body 211. In this embodiment, the lever 242 is multiplied by 16.7 times by using a boosting force of 1.8 times with the push plate and 9.3 times with the lever 242 and the cam 231, and the lever 242 is operated lightly. Thus, the ball shaft 201 is firmly fixed to the case main body 211. As described above, the pan head apparatus of the present invention can loosen and tighten the ball shaft by switching the loose position and the tightening position of the lever.

  In addition, by adjusting the vertical position of the adjustment screw 261 and changing the position where the adjustment screw 261 contacts the screw contact point 224, the position of the fulcrum changes, and the fixing force when the lever 242 is set to the tightening position is increased. Can be adjusted.

  Next, the action and effect of the ball shaft 201 having the ball portion 203 composed of the lower sphere 203a and the upper sphere 203b having different center positions as described above will be described with reference to FIG. FIGS. 7A and 7B are stress explanatory views showing a comparison between the conventional ball shaft fixing method and the ball shaft fixing method of the present invention. Since the ball portion of the conventional ball shaft 111 is a perfect sphere, the contact portion between the ball portion and the base 121 and the case body 101 (see FIGS. 9 and 10 / only the contact line is indicated by a broken line) is a circle having a diameter of φ1. (It is actually a spherical surface, but for convenience of explanation, it will be explained as a circle shown in FIG. 7A). This circle is located at a radius R1 from the center of the ball portion, as with the other portions of the surface of the ball portion. Therefore, the point is always located on the circle with respect to the rotation of the ball portion of the ball shaft 111. On the other hand, assuming that the point has rotated around the center point of the ball portion, the point on the circle moves along the circle of the ball shaft 111, and therefore has a mechanical restraining force other than friction. Absent. Therefore, the rotational moment applied to the camera screw was constrained only by the friction caused by the materials of the two contact portions having a diameter of φ1.

  On the other hand, assuming that the ball shaft 201 rotates in the direction of the arrow R about the point A, the lower ball 203a centered on the point A has a ball bearing 212 (see FIG. In B), the arc portion (not shown / only the contact line is indicated by a broken line) is restricted by friction as in the conventional ball shaft 111. On the other hand, the center point of the upper sphere 203b is a point B at a position different from the point A, and the upper sphere 203b and the ball shaft pressing portion 222 of the pressing plate 221 (not shown in B of FIG. 7 / only the contact line is a broken line) Since the contact circle of (indicated) does not exist on the spherical surface centered on the point A, the direction of pressing against the ball axis pressing portion 222 by the rotational moment applied to the camera screw 202 at the contact point of FIG. A force vector is generated.

  As shown in the partially enlarged view of FIG. 7B, the contact point C moves in the direction of the vector c by the rotation of the upper sphere 203b in the direction of arrow R. When the vector c is decomposed into the tangential surface direction at the point C and the vertical direction thereof, the vector ch and the vector cv are obtained, respectively. Since the vector ch is a vector in the tangential surface direction of the upper sphere 203b, no pressing force is generated on the ball shaft pressing portion 222. Further, the vector cv is also a vector in a direction away from the ball shaft pressing portion 222, so that no pressing force is generated. That is, at the contact point C, the ball shaft pressing portion 222 does not hinder the rotation of the upper sphere 203b.

  On the other hand, the contact point D moves in the direction of the vector d by the rotation of the upper sphere 203b in the direction of arrow R. When the vector d is decomposed into the tangential surface direction at the point D and the vertical direction thereof, they become a vector dh and a vector dv, respectively. Since the vector dh is a vector in the tangential surface direction of the upper sphere 203b, no pressing force is generated on the ball shaft pressing portion 222. However, the vector dv generates a pressing force because it is a vector in the direction toward the ball shaft pressing portion 222.

  Since this vector dv acts in the direction in which the upper sphere 203b of the ball shaft 201 bites into the ball axis pressing portion 222, the rotational moment applied to the camera screw 202 is the ball axis pressing portion 222 of the upper sphere 203b and the pressing plate 221. The rotation is mechanically constrained by the contact circle and a firm fixation can be realized. This effect can be easily verified by applying the oil or the like to the ball portion 203 of the ball shaft 201 and restricting the rotation of the ball shaft 201 even if the frictional force is reduced.

  In FIG. 6, the sphere centers of the lower sphere 203a and the upper sphere 203b are formed at positions where straight lines extending from the points A and B to the outer circumference of the upper sphere 203b and the lower sphere 203a intersect each other. Needless to say, the centers need not be at the same position. For example, the same effect can be obtained even with a ball axis in which two sphere centers are separated.

  FIG. 8 shows another embodiment of the second embodiment. In other embodiments, a rib 214 is formed at the bottom of the case body, and an elastic body 215 is provided at the upper end of the rib 214. The elastic body 215 may also use a spring instead of rubber or sponge. Similarly to the other embodiments of the first embodiment, the elastic body 215 also lifts the pressing plate 221 upward, and the opening edge of the ball shaft pressing portion 222 of the pressing plate 221 has an upper ball 203b of the ball shaft. It is comprised so that it may not touch. Thereby, the movement of the ball shaft 201 becomes smooth.

  The pan head apparatus according to the present invention is a pan head apparatus that can be installed on a moving body such as a car, capable of realizing strong fixing strong against vibration with inexpensive parts, enabling one-hand operation, and having no deterioration of fixing force due to vibration. Useful as.

It is a component block diagram of the pan head apparatus in Embodiment 1 of this invention. It is sectional drawing of the pan head apparatus in Embodiment 1 of this invention. It is a partial expanded sectional view of the other pan head apparatus in Embodiment 1 of this invention. It is a use condition figure of the pan head device in Embodiment 1 of the present invention. It is a component block diagram of the pan head apparatus in Embodiment 2 of this invention. It is sectional drawing of the pan head apparatus in Embodiment 2 of this invention. It is explanatory drawing explaining the stress of a ball axis. It is a partial expanded sectional view of the other pan head apparatus in Embodiment 2 of this invention. It is the perspective view which fractured | ruptured a part of conventional pan head apparatus. It is sectional drawing of the conventional pan head apparatus.

Explanation of symbols

201 Ball shaft 203 Ball portion 203b Upper sphere 203a Lower sphere 204 Shaft portion 211 Case body 212 Ball bearing 215 Elastic body 221 Press plate 222 Ball shaft pressing portion 223 Cam contact surface 231 Cam 232 First flat portion 233 Second flat 241 Lever shaft 242 Lever 251 Lid 261 Adjustment screw 271 Mounting bracket 301 Camera

Claims (3)

A ball shaft having a ball portion and a shaft portion;
A case main body provided with a ball bearing for holding the ball portion of the ball shaft;
A pressing plate capable of pressing the ball shaft against the ball bearing;
A cam that presses the push plate in the direction of the ball axis by rotating a lever;
The ball portion is composed of an upper sphere and a lower sphere whose center positions are different from each other,
The cam has a first flat portion and a second flat portion having a distance from the rotation center of the cam longer than that of the first flat portion,
When the first flat portion of the cam presses the pressing plate by rotating the lever, the pressing plate does not press the ball shaft,
When the second flat portion of the cam presses the pressing plate by rotating the lever, the pressing plate presses the ball shaft, whereby the ball shaft is moved to the ball bearing and the pressing plate. A pan head device that is clamped and fixed to the head.   The pan / tilt head device according to claim 1, further comprising an adjustment screw that varies a position of the pressing plate that presses the ball shaft.   2. The pan head apparatus according to claim 1, further comprising an elastic body that biases the pressing plate in a direction in which the pressing plate is separated from the ball portion of the ball shaft.

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