(19)
(11) EP 1 143 096 A1

(12) EUROPEAN PATENT APPLICATION

(43) Date of publication:
10.10.2001 Bulletin 2001/41

(21) Application number: 00830265.5

(22) Date of filing: 07.04.2000
(51) International Patent Classification (IPC)7E05F 15/04, F15B 15/08
(84) Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
Designated Extension States:
AL LT LV MK RO SI

(71) Applicant: SITES S.r.l.
23870 Cernusco Lombardone (LC) (IT)

(72) Inventor:
  • Turina, Roberto
    23870 Montevecchia (LC) (IT)

(74) Representative: Gislon, Gabriele 
Marietti, Gislon e Trupiano S.r.l. Via Larga, 16
20122 Milano
20122 Milano (IT)

   


(54) Rotating drive apparatus


(57) A rotating drive apparatus comprises a shaft (2) or other tubular element, a stator comprising a pair of fixed elements (3, 4) spaced along the shaft (2) and comprising inclined surfaces (5,6), a rotor comprising a piston (7) mounted on the shaft (2) and comprising means (13, 14) of engagement of the inclined surfaces of the fixed elements (2, 3) of the stator to rotate the piston when this moves following admission of a fluid into at least one chamber (9, 10) located between piston and fixed elements.




Description


[0001] The present invention relates to a rotating drive apparatus, i.e. a device able to impart rotation to doors, gates and similar elements.

[0002] Various types of rotating drive apparatuses are known. A traditionally known type is one that uses an external telescopic arm that extends between a support and the element to be rotated. This type of device is bulky and potentially dangerous and can't therefore be used in many applications such as for instance in vehicles. To resolve this problem, pneumatic or hydraulic rotating drive apparatuses have been proposed comprising a stator and a coaxial rotor, in which an internal piston moves a lug in one or more slots to rotate the rotor. Examples of these embodiments are described in US-A-4838102; DE-A-2538529 and in EP-A-0823528 (in the name of the present applicant).

[0003] The known coaxial drive apparatuses referred to above are compact and have many advantages compared to telescopic actuators, but they have the disadvantage of being relatively complex to produce and of being distorted by bumps or accidental knocks -- something which is, however, very frequent when used in applications for machines or industrial plants.

[0004] The purpose of the present invention is to produce a coaxial drive apparatus that is simple and economical to produce, of reduced dimensions and also able to withstand heavy use.

[0005] Such purpose is achieved by the present invention, which relates to a rotating drive apparatus of coaxial type, comprising tubular guide means defining a longitudinal axis, a stator consisting of a pair of fixed elements located along said guide means with a space between them and comprising surfaces inclined with respect to the said axis of the guide means, a rotor constituted by a piston located on the guide means between said fixed elements, said piston comprising means for engaging the inclined surfaces of both said fixed elements in a sliding way, and a jacket cooperating with said piston and said fixed elements to define at least one chamber for feeding a fluid.

[0006] Preferably, the angle α formed between the inclined surface and the longitudinal axis of the guide means is between 30° and 60°.

[0007] According to another preferential embodiment, the piston, too, has inclined surfaces that are complementary to the inclined surfaces of the fixed elements and match up with them at least at the end of the rotary movement of the piston.

[0008] According to a further aspect the invention, the stator comprises the tubular guide means and the piston rotates together with the external jacket.

[0009] The drive apparatus according to the invention has many advantages with respect to the preceding technique. In the first place, it has much reduced dimensions with respect to known coaxial drive mechanisms, so that it can be used in a far wider range of applications. Furthermore, it is simpler and less expensive to produce. Finally, it is stronger and also stands up well to heavy use such as in gates of freight elevators and similar, where it is subject to frequent bumps.

[0010] The invention will now be described in more detail by way of example and not of limitation, with reference to the enclosed drawings, where:
  • Fig. 1 is a plan view of the longitudinal section of an embodiment according to the invention;
  • Fig. 2 is a side view in section of the embodiment of fig. 1;
  • Fig. 3 is a side view of the device of figures 1 and 2, without jacket;
  • Fig. 4 is a side view of the device of fig. 3 after the piston has rotated; and
  • Fig. 5 is a view in longitudinal section of a further embodiment of the device according to the invention.


[0011] With reference first of all to figs. 1 and 2, the rotating drive apparatus 1 according to the present invention comprises tubular guide means 2, such as the shaft shown in fig. 1 and 2, defining a longitudinal axis A-A,' a stator constituted by the pair of base-plates or similar fixed elements 3 and 4 located spaced from each other along the A-A' axis of guide shaft 2. In the embodiment of figures 1-4 the fixed elements 3 and 4 are arranged at the extremities of guide means 2. As can be seen, fixed elements 3 and 4 are equipped with respective surfaces 5 and 6 inclined with respect to the axis of guide means 2 and there is a rotor between the surfaces 5 and 6 constituted by a piston located on guide shaft 2 between the two fixed elements 3 and 4. The piston 7 consists of a hollow cylinder inside which shaft 2 passes and comprises means for engaging in a sliding way the inclined surfaces 5 and 6 of both the fixed elements 3 and 4. The piston 7 can rotate along and around the guide means constituted by the shaft 2.

[0012] Furthermore, there is a jacket 8 cooperating with piston 7 and with fixed elements 3 and 4 to define two chambers 9 and 10 fed by fluid from a pneumatic or, preferably, hydraulic system. The hydraulic or pneumatic systems are of known type and are not shown. The fluid is fed (alternatively) to the chambers 9 and 10 through two pipes respectively 11 and 12 that cross the fixed base-plates 3 and 4 and part of the guide shaft 2; gaskets 20 located on the piston 7 and on the shaft 2 guarantee the seal between the two chambers 9 and 10.

[0013] The surfaces 5 and 6 of fixed elements 3 and 4 are inclined with respect to the longitudinal axis A-A' of the shaft at an angle α, such as to impart a rotation to the piston when this moves; in other words, the surfaces of the fixed elements are such as to transform part of the axial push given to the piston in a transversal push and thus have the piston to rotate. Preferably, the angle α is between 20° and 75° and more preferably between 30° and 60°; in fig.2 the angle is shown with reference to the external surface of the jacket 8 (parallel to the A-A' axis) for better clarity and simplicity of the drawing.

[0014] The means present on the piston for engaging surfaces 5 and 6 of base-plates 3 and 4 in a sliding way could be of various types, provided that they carry out the function of following said surfaces and of forcing the piston-rotor to rotate when it moves following the admission of the fluid into one of the two chambers. For instance, such means could be constituted by one or more fingers extending from the piston and engaging with the corresponding base-plates.

[0015] Preferably, as shown in the figures, the means for engaging the inclined surfaces 5 and 6 of fixed elements 3 and 4 in a sliding way consist of inclined surfaces 13 and 14 of the piston 7, that is complementary to inclined surface 5 and 6, respectively, of fixed elements 3 and 4. Since surfaces 13 and 14 are of complementary form to those of the surface 5 and 6 of the base-plates, at the end of the movement of rotation of piston the surfaces 13 and 14 match up with the surfaces 5 and 6 and, in this way, supply high resistance to any knocks. According to this embodiment, as shown in the figures, one of the surfaces of the piston matches with the corresponding surface of the base-plate only at the end of the piston run, i.e. when the piston has rotated completely. During the rotation, there is no significant matching. If better resistance to knocks during rotation of the piston is desired, the surfaces of piston and base-plates can be so shaped that they are constantly at least partially matched up.

[0016] In the embodiment of figs. 1-4 the guide means, i.e. the shaft 2, isa integral with fixed elements 3 and 4 that constitute the stator of the device. The piston 7, i.e. the rotor of the device, engages with jacket 8 and rotates with it; jacket 8 is in its turn locked to the element to be rotated (not shown) in a known way. A slot and key system is preferably used to lock piston 7 to jacket 8; the piston 7 has a pair of slots 15 that engage in a sliding way with a corresponding pair of keys 16 that engage in their turn slots 17 cut into the jacket 8. The length of slot 15 is equal to the stroke of the piston plus the length of the key; bigger keys require longer slots but give better structural strength.

[0017] As an alternative to embodiment described above, the jacket 8 could be fixed and locked to elements 3 and 4 and constitute the stator of the device (fig. 5), while the shaft 2 could rotate.

[0018] In such an embodiment, the guide shaft 2 is engaged through at least one key 18 and slot 19, with the piston 7 and it can rotate with it and with the door, gate or other element to be rotated to which the guide shaft is fixed. Preferably, there will be one or two slots on guide means 2 whose length is determined in the way described above for the embodiment of figs. 1-4.

[0019] As above mentioned, the stator comprises two fixed elements, or base-plates, 3 and 4 located to the sides of the piston 7 and comprising inclined surfaces 5 and 6 that are engaged in a sliding way with the piston 7 so as to cause its rotation when the piston is moved. In the preferential embodiments of figs. 1-5 surfaces 5 and 6 of the fixed elements are equal and are arranged as mirror images with respect to a median plane transversal to the device; in this disposition the means for engaging the inclined surface in a sliding way are rotated with respect to each other by an angle that corresponds to the angle through which it is desired to rotate the element (door, gate or other). That is clearly visible in fig. 3, where it can be seen that vertices 21 and 22 of inclined surfaces 14 and 13 are rotated through an angle of around 90° with respect to each other. Alternatively, the vertices of surfaces 5 and 6 can be rotated through the required angle and the piston presents surfaces or means of engagement that are mirror images of each other (zero angle).

[0020] The device according to the invention could furthermore be provided with means of retention to maintain the fluid in the chamber (9 or 10) into which it has been introduced and in this way prevent the door or gate fixed to the device being rotated manually. Means of retention of this type are known in the art of hydraulic circuits and are available commercially; such means are not an object of the present invention and are not illustrated in the enclosed drawings. In some applications the means of retention are not necessary; particularly, in applications such as elevators the means of retention are missing and the door (when at the floor) can be rotated manually and therefore opened also in case of failure of electric power.

[0021] In operation, oil is introduced for instance through the channel 12 in the chamber 10, forcing the piston toward the left side of fig. 2. The piston is initially in the position shown in fig. 1, 2 and 3. The piston engages surface 6 of fixed element 4 with the vertex 21 of its own surface 14 and the linear movement is thus transformed partially into rotation of piston 7 around guide 2, according to arrow F of fig. 3; the movement finishes when the surface 14 comes to rest completely on surface 6, in the position shown in fig. 4. To return to the position of figs. 2 and 3 oil is fed to chamber 9 through the channel 11 and the piston rotates accordingly in the reverse direction to that of the preceding rotation, coming to rest on fixed element 3.


Claims

1. A coaxial rotating drive apparatus, characterized by comprising tubular guide means (2) defining a longitudinal axis (A-A'), a stator comprising a pair of fixed elements (3,4) located with a space between them along said guide means (2) and comprising surfaces (5, 6) inclined with respect to said axis of the guide means, a rotor comprising a piston (7) located on said guide means (2) between said fixed elements (3, 4), said piston comprising means for engaging the inclined surfaces (5, 6) of both said fixed elements (3, 4) in a sliding way, and a jacket (8) cooperating with said piston (7) and with said fixed elements (3, 4) to define at least one chamber (9, 10) for feeding of a fluid.
 
2. A drive apparatus according to Claim 1, characterized by the angle α formed between said inclined surface (5, 6) and said longitudinal axis (A-A') of the guide means (2) being within the range of 20° to 75° and preferably 30° to 60°.
 
3. A drive pparatus according to Claim 2, characterized by said guide means (2) being secured to said fixed elements (3, 4) and said piston (7) being engaged with said jacket (8) and able to rotate with it.
 
4. A drive apparatus according to Claim 2, characterized by said jacket (8) being secured said fixed elements (3, 4) and said guide means (2) being engaged with said piston (7) and rotating with it.
 
5. A drive apparatus according to any of the preceding Claims, characterized by there being two chambers (9, 10) provided on opposite sides of said piston (7).
 
6. A drive apparatus according to any of the preceding Claims, characterized by said means for engaging the inclined surfaces (5,6) of both said fixed elements (2, 3) in a sliding way being constituted by inclined surfaces (13, 14) of the piston (7), that are complementary to said inclined surfaces (5, 6) of said fixed elements (3, 4) and matching up with them at least at the end of the rotational movement of the piston.
 
7. A drive apparatus according to any of the preceding Claims, characterized by said fixed elements (3, 4) being arranged as mirror images of each other.
 
8. A drive apparatus according to Claim 7, characterized by said means for engaging said inclined surfaces in a sliding way being arranged rotated with respect to each other.
 
9. A drive apparatus according to an any of the preceding Claims characterized by said piston (7) being engaged with said jacket (8) or with said guide means (2) through a key (16) sliding in a slot (17).
 




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