JP2007055715A - Elevating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elevating device having a compact balance mechanism with a long service life. <P>SOLUTION: In this elevating device 10, an upper pole 2 on which a camera 3 is put and fixed is connected with expansion/contraction means mounting brackets 5 which can be slide and moved with respect to lower state poles 1. Each lower spindle 8 is disposed to a lower part of each lower part of the lower state pole 2, and an upper spindle 7 is disposed to the expansion/contraction means mounting bracket 5 in parallel to the lower spindle 8 and to be separated in horizontal direction from the lower spindle 8 by a predetermined distance A, and both ends of each gas spring 6 are connected at the lower spindle 8 and the upper spindle 7. The predetermined distance A is set so that both of the minimum value and the maximum value of vertical component F' between the minimum value and the maximum value of an extension amount S of the gas spring 6 are balanced with respect to the gravity acting in an elevating direction of all of the expansion/contraction means mounting brackets 5, the upper pole 2, and the camera 3. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an elevating apparatus that can be suitably used as an elevating apparatus for elevating a television camera, for example, when shooting in a studio of a television station, and more particularly to a balance mechanism thereof.

2. Description of the Related Art Conventionally, for example, a lifting device that lifts and lowers a television camera has been known that includes a balance mechanism for keeping a stationary state at an arbitrary position within the lifting range.
For example, in the technique described in Patent Document 1, a gas pressure balanced balance mechanism including an unbalance compensator having a toggle mechanism using a link and a constant load spring is disclosed. In general, the gas pressure of the gas cylinder increases when the lifting device is reduced, and decreases when the lifting device is extended, but with this balance mechanism, when the lifting device is reduced and extended. The unbalance compensator compensates for the difference in gas pressure force that occurs in the up-and-down direction (vertical direction).
JP-A-6-100300 Japanese Patent Application No. 2003-345985 (unpublished)

By the way, in particular, in a lifting device for a television camera, since its maneuverability is important, it is desirable to make the lifting device compact. Therefore, for example, if the technique described in Patent Document 1 is taken as an example, it is preferable to configure the gas filling chamber of the gas cylinder and the unbalance compensation device to be smaller.
However, in order to make this unbalance compensation device compact, it is effective to reduce the gas pressure fluctuation in the gas filling chamber due to expansion and contraction of the lifting device, for example. The filling chamber must be enlarged. On the other hand, if this gas filling chamber is made small, the gas pressure fluctuation in the gas filling chamber becomes large, so the unbalance compensator must be enlarged accordingly. Therefore, it is difficult to make the lifting device compact.

As a balance mechanism in this type of lifting device, for example, a balance mechanism having a constant load spring in which a leaf spring is wound in a roll shape as described in Patent Document 2 is known. According to the balance mechanism using the constant load spring, a relatively compact balance mechanism can be configured. However, the balance mechanism using the constant load spring generally has a room for improvement since its fatigue life is shorter than that of the gas pressure balance type balance mechanism.
Therefore, the present invention has been made paying attention to such a problem, and an object thereof is to provide a lifting device having a balance mechanism that is compact and can have a long life.

  In order to solve the above-described problems, the present invention acts on a casing, a moving part that is slidable with respect to the casing within a predetermined raising / lowering range, and the moving part and the entire accessory member provided in the moving part in the raising / lowering direction. An elevating device comprising a balance mechanism that cancels out the gravitational force and maintains a stationary state at an arbitrary position within the predetermined elevating range, wherein the balance mechanism is pivotally supported at both ends by the housing and the moving part. Gas springs that are obliquely connected to each other, and the gas springs are provided with the minimum value and the maximum value of the vertical component force between the minimum value and the maximum value of the extension amount of the gas spring. It is characterized in that the entire incidental member is connected obliquely at a position that balances with gravity acting in the up-and-down direction.

  According to the present invention, only the gas spring is used as a component of the balance mechanism, and the minimum value and the maximum value of the vertical component force between the minimum value and the maximum value of the extension amount of the gas spring are moved. Since the balance mechanism is configured by being connected obliquely at a position that balances with the gravity acting in the up-and-down direction on the entire part and the auxiliary member provided in the same, a vertical component force according to the slide movement in the up-and-down range Can be balanced at any time with the gravity acting in the ascending / descending direction on the moving part and the entire incidental member provided therein. Therefore, this balance mechanism can have a compact configuration like the constant load spring type balance mechanism, for example, and can have a longer life than, for example, a constant load spring type balance mechanism.

The present invention also includes a lower pole, an extension means mounting bracket that is slidable with respect to the lower pole via a linear guide device in a predetermined lifting range, an upper pole connected to the extension means mounting bracket, A lower support shaft provided at a lower portion of the pole, an upper support shaft provided in the expansion / contraction means mounting bracket in parallel to the lower support shaft and at a predetermined distance in the horizontal direction, and the lower support shaft and the upper support shaft. Both ends of the support shaft are connected to each other, and the lifting device includes a gas spring that supports the upper pole via the expansion / contraction means mounting bracket. The predetermined horizontal distance between the upper support shaft and the lower support shaft is telescopic. Gravity acting in the up-and-down direction on the means mounting bracket, the upper pole, and all the incidental members provided in the means is divided into the vertical direction between the minimum value and the maximum value of the extension amount of the gas spring. Minimum and maximum is characterized in that it is set to a distance both balanced.
Here, in this specification, “balance” means that the moving unit and the entire incidental member provided in the moving unit are stationary at an arbitrary position in the predetermined ascending / descending range, including friction loss and the like. It means keeping.

According to the present invention, the distance in the horizontal direction between the upper support shaft and the lower support shaft to which both ends of the gas spring are connected is determined by using the gas spring, the telescopic means mounting bracket, the upper stage pole, and the incidental member provided to the same. Since the gravity acting on the whole in the up-and-down direction and the minimum value and the maximum value of the vertical component force between the minimum value and the maximum value of the extension amount of the gas spring are both set to the distance, the lift range The vertical component force corresponding to the slide movement at the point can be balanced with the gravity acting in the ascending / descending direction on the entire moving part and the accompanying member provided therein. Therefore, as a part of this balance mechanism, only a gas spring is used, so that it is possible to provide an elevating device provided with a balance mechanism having a compact configuration. And since the gas spring is used, it can be made longer life than a constant load spring type balance mechanism, for example.
Here, the lifting device according to the present invention can be suitably used as a lifting device that lifts and lowers a television camera.

  ADVANTAGE OF THE INVENTION According to this invention, the raising / lowering apparatus provided with the balance mechanism which is compact and can be made long-life can be provided.

Hereinafter, an embodiment of a lifting device provided with a balance mechanism according to the present invention will be described with reference to the drawings as appropriate.
FIG. 1 is a schematic configuration diagram showing an embodiment of a lifting device according to the present invention.
As shown in the figure, the lifting device 10 includes a substantially U-shaped lower pole 1. The lower pole 1 is configured as a casing of the lifting device 10, and the inner side surfaces 1 b of the side walls 1 a erected on both the left and right sides thereof face each other toward the substantially U-shaped recess 1 c side. Two sets of linear motion guides 4 that are a pair of linear motion guide devices arranged in parallel are attached in parallel (that is, one set is further mounted on the back side in the drawing in the figure).

The linear guide 4 is configured to include a guide rail 4a and a slider 4b. The guide rail 4a is mounted in the vertical direction that is the up and down direction, and the slider 4b is slidable on the guide rail 4a. Are provided for each guide rail 4a. Stretching means mounting brackets 5 having flat plate-like horizontal portions 5a and fixed block portions 5b that can be attached to the respective sliders 4b are spanned between the opposing sliders 4b. It is connected to. As a result, the expansion / contraction means mounting bracket 5 is configured as a moving part that is slidable within a predetermined lifting range W via the linear motion guide 4. And the appropriate place of the upper stage pole 2 is attached to this expansion-contraction means attachment bracket 5 with an axis | shaft turned up and down. Further, a camera 3 is placed and fixed on the upper pole 2. The upper pole 2 and the camera 3 correspond to the incidental members, respectively.
Here, the elevating device 10 balances the gravity acting on the elevating direction of the telescopic means mounting bracket 5, the upper pole 2 and the camera 3 provided in the elongating means mounting bracket 5, and the arbitrary elevating range W in the predetermined elevating range W. A balance mechanism is further provided to keep the stationary state at the position.

Hereinafter, this balance mechanism will be described in detail.
As shown in FIG. 1, a lower support shaft 8 having a horizontal axis is provided at the lower portion of the lower pole 1. Further, the telescopic means mounting bracket 5 is provided with an upper support shaft 7 having a horizontal axis in a position parallel to the lower support shaft 8 and separated by a predetermined distance A in the horizontal direction. The gas spring 6 is disposed on the near side and the far side in the drawing, with one end pivotally supported by the upper support shaft 7 and the other end pivoted by the lower support shaft 8. As a result, the gas spring 6 has a balance mechanism in which both ends thereof are obliquely connected between the lower pole 1 and the extension means mounting bracket 5 so that the upper pole 2 can be supported via the extension means attachment bracket 5. Yes.

  Further, in this balance mechanism, the setting position of each gas spring 6 is such that both the minimum value and the maximum value in the vertical component force between the minimum value and the maximum value of the extension amount are the extension means mounting bracket 5 and this. Are connected to the upper pole 2 and the entire camera 3 obliquely at a position balanced with gravity acting in the up-and-down direction. In other words, the predetermined distance A in the horizontal direction between the upper support shaft 7 and the lower support shaft 8 is against the gravity acting in the up-and-down direction on the expansion / contraction means mounting bracket 5, the upper pole 2 and the camera 3 provided therein. The minimum value and the maximum value in the vertical component force between the minimum value and the maximum value of the extension amount of the gas spring 6 are both set to a balanced distance.

Hereinafter, the setting position of the gas spring 6 in this balance mechanism will be described in more detail.
Here, FIG. 2 is an explanatory view showing the vertical component force by the gas spring 6, in which L is the length of the gas spring when the extension amount is S, and L0 is the gas at the time of the minimum reduction (S = 0). Spring length (constant), α is the inclination of the gas spring connected obliquely with respect to the horizontal plane, S is the amount of extension of the gas spring, F1 is the pushing force of the gas spring when the amount of extension is S, and F0 is at the time of contraction (S = 0) Gas spring pushing force (constant = P0 × V0), A is a predetermined horizontal distance between the upper support shaft 7 and the lower support shaft 8, and 0 <A <L0 To do.

FIG. 3 is an explanatory diagram showing the relationship between the amount of extension S of the gas spring and the variation in the pushing force. In FIG. 3, P1 is the pressure in the gas spring when the amount of extension S is S, and P0 is the time of the minimum reduction (S = 0) Gas spring internal pressure (constant), d is the rod diameter (constant) of the gas spring, V1 is the gas spring internal volume when the extension amount is S (V1 = V0 + πd ² S / 4), and V0 is the minimum contraction (S = 0) Gas spring inner volume (constant).
From the equation of state:
P0 ・ V0 = P1 ・ V1
P1 = (V0 / V1) P0
= (V0 / (V0 + πd ² S / 4)) P0
Here, when πd ^2/4 = C1 (constant),
P1 = (V0 / (V0 + C1 · S)) P0

From FIG. 3, the gas spring 6 has a pressing force due to the internal pressure applied to the cross section of the rod.
C1 · P1 = (V0 / (V0 + C1 · S)) C1 · P0
F1 = (V0 / (V0 + C1 · S)) F0 (1)
From FIG.
F ′ = F1sin α (2)
H = Lsinα ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Equation (3)
H = ((L0 + S) ² −A ² ) ^1/2 ... Equation (4)
F ′ = (H / L) F1 (from formulas (2) and (3))
= ((((L0 + S) ² −A ² ) ^1/2 / (L0 + S)) · F1 (L = L0 + S, from equation (4))
= (1-A ² / (L0 + S) ² ) ^1/2 · F1
Substituting equation (1) into F1,
F ′ = (1−A ² / (L0 + S) ² ) ^1/2 · (V0 / (V0 + C1 · S)) F0 Formula (5)

Next, this equation (5) is represented in a graph as shown in FIG. 4 shows the pressing force F of the gas spring 6 with respect to the extension amount S of the gas spring 6 when the predetermined distance A in the horizontal direction between the upper support shaft 7 and the lower support shaft 8 in FIG. 2 is changed. It is a graph which shows the change of vertical direction component force F '.
When the predetermined distance A = 0,
F ′ = (V0 / (V0 + C1 · S)) F0... Graph (a) in FIG.
Here, when S = 0, F ′ = F0, and when S = ∞, F ′ = 0.
When the predetermined distance A = L0,
F ′ = (1−L0 ² / (L0 + S) ² ) ^1/2 · (V0 / (V0 + C1 · S)) F0... Graph in FIG. 4 (b)
Here, when S = 0, F ′ = 0, and when S = ∞, F ′ converges to 0 while approaching the graph of (A).

When the predetermined distance A = A1,
F ′ = (1−A1 ² / (L0 + S) ² ) ^1/2 · (V0 / (V0 + C1 · S)) F0... Graph in FIG.
Here, when S = 0, F ′ = F0 · (1−A1 ² / L0 ² ) ^1/2 , and when S = ∞, F ′ converges to 0 while approaching the graph of (A). .

When the predetermined distance A = A2, A2> A1,
F ′ = (1−A2 ² / (L0 + S) ² ) ^1/2 · (V0 / (V0 + C1 · S)) F0... Graph (d) in FIG.
Here, when S = 0, F ′ = F0 · (1−A2 ² / L0 ² ) ^1/2 , and when S = ∞, F ′ converges to 0 while approaching the graph of (A). .

When the predetermined distance A = A3, A3>A2> A1,
F ′ = (1−A3 ² / (L0 + S) ² ) ^1/2 · (V0 / (V0 + C1 · S)) F0... Graph in FIG.
Here, when S = 0, F ′ = F0 · (1−A3 ² / L0 ² ) ^1/2 , and when S = ∞, F ′ converges to 0 while approaching the graph of (A). .

  From the above consideration, the knowledge that the gas spring 6 can be obliquely connected to intentionally create a range (for example, the range shown in FIGS. 2 and 4) in which the fluctuation in the vertical component force F ′ is small. Obtained. Therefore, in the balance mechanism of the lifting device 10, based on this knowledge, the minimum value and the maximum value of the vertical component force F ′ between the minimum value and the maximum value of the extension amount S of the gas spring 6 are determined by the extension means attachment. A position that balances against the gravity acting on the bracket 5, the upper pole 2 and the camera 3 provided in the bracket 5 in the up-and-down direction is selected as a predetermined distance A in the horizontal direction between the upper support shaft 7 and the lower support shaft 8.

  Thus, the lifting device 10 cancels the gravity acting in the lifting direction on the expansion / contraction means mounting bracket 5, the upper pole 2 and the camera 3 provided therein, and maintains an arbitrary position in the predetermined lifting range. It is possible. The range where the fluctuation is small means that the moving part and the entire incidental member provided in the moving part and the entire accessory member including the friction loss can substantially keep an arbitrary position within the predetermined lifting range, that is, can be balanced. It is a range.

Next, operations and effects of the balance mechanism of the lifting device 10 will be described.
As described above, according to the lifting device 10, the vertical component force F ′ of the gas spring 6 satisfies the magnitude of the force required for lifting and the width of the fluctuation of the vertical component force F ′ is small. Since the dimension A (predetermined distance) is determined (for example, the above-described A1, A2, A3, etc.), the vertical component force F ′ with little fluctuation is obtained even if the extension amount S of the gas spring 6 changes. It can be obtained at any time. The vertical component force F ′ is set to a magnitude that cancels out the gravity acting on the telescopic means mounting bracket 5, the upper pole 2 and the camera 3 in FIG. The operator can easily move the pole 3 up and down by manually moving the pole 2 up and down.

Since only the gas spring 6 is used as a component part of the balance mechanism, the lifting device 10 having a balance mechanism with a compact configuration can be provided, for example, like the constant load spring type balance mechanism.
Further, since the gas spring 6 is used in this balance mechanism, the life can be made longer than that of, for example, a constant load spring type balance mechanism.

It should be noted that the lifting device and the balance mechanism thereof according to the present invention are not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the lifting device according to the present invention has been described as an example using the lifting device for lifting and lowering the television camera. However, the present invention is not limited thereto, and various objects can be lifted and lowered. It can be suitably used as a lifting device provided with a balance mechanism that keeps a stationary state at an arbitrary position in the range.

It is a schematic block diagram which shows one Embodiment of the raising / lowering apparatus which concerns on this invention. It is a figure explaining the vertical direction component force etc. by a gas spring. It is a figure explaining the relationship between the amount of elongation of a gas spring, and the change of the pushing force. Changes in the vertical component force F ′ of the pressing force F of the gas spring with respect to the gas spring elongation amount S when the horizontal distance A between the upper and lower support shafts in FIG. 2 is changed. It is a graph to show.

Explanation of symbols

1 Lower pole (housing)
2 Upper pole (supplementary member)
3 Camera (supplementary member)
4 linear motion guide (linear motion guide device)
5 Extension means mounting bracket (moving part)
6 Gas spring 7 Upper support shaft 8 Lower support shaft 10 Lifting device A Predetermined horizontal distance between upper support shaft and lower support shaft A1 Horizontal distance between upper support shaft and lower support shaft (constant)
A2 Horizontal distance between upper and lower spindles (constant)
A3 Horizontal distance between the upper and lower spindles (constant)
H Vertical distance between upper and lower support shafts L Gas spring length when elongation is S L0 Gas spring length when constant reduction (S = 0) (constant)
S Gas spring elongation α Inclination of the gas spring with respect to the horizontal plane P0 Gas spring internal pressure (constant) at the time of the minimum reduction
P1 Gas spring internal pressure when the amount of elongation is S V0 Gas spring internal volume when constant reduction (S = 0) (constant)
V1 Gas spring inner volume when elongation is S d Rod diameter of gas spring (constant)
C1 Rod section of gas spring (C1 = πd2 / 4, constant)
F0 Gas spring pushing force (constant) at maximum reduction (S = 0)
F1 Gas spring pushing force when the extension amount is S F 'Vertical force of the gas spring

Claims (2)

A casing, a moving section that can slide relative to the casing within a predetermined lifting range, and the gravity that acts in the lifting direction on the entire moving section and the incidental member provided in the moving section are offset in the predetermined lifting range. A lifting device including a balance mechanism that keeps the stationary state at any position of
The balance mechanism has a gas spring that is pivotally supported at both ends by the housing and the moving part and obliquely connects each other, and the gas spring has a vertical distribution between a minimum value and a maximum value of the extension amount. A lifting device characterized in that the minimum value and the maximum value of force are obliquely connected to the moving part and the entire incidental member provided in the moving part at a position that balances with the gravity acting in the lifting direction.   The elevating device according to claim 1, wherein the elevating device elevates and lowers the television camera.

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