Abstract
The present invention relates to a centrifuge, in particular, a laboratory centrifuge, with a housing comprising a centrifuge lid, which delimits the centrifuge to the outside, a rotor and a rotor cover for closing the rotor, a connecting device comprising a holding arm and a holder being provided, via which the rotor cover and the centrifuge lid can be detachably connected with each other in such a way that the rotor cover is lifted off of the rotor upon opening of the centrifuge lid and is placed on the rotor upon closing the centrifuge lid. The holding arm is detachably and movably mounted in the holder during opening and closing of the centrifuge lid, and the holding arm and the holder are spaced via a gap space when the centrifuge lid is closed.
Claims
1. A centrifuge, comprising: a housing comprising a centrifuge lid which is a hinged lid and delimits the centrifuge to the outside; a rotor; a rotor cover for closing the rotor; and a connecting device comprising a holding arm and a holder, via which the rotor cover and the centrifuge lid are detachably connected with each other in such a way that the rotor cover is lifted off the rotor upon opening of the centrifuge lid and is placed on the rotor upon closing of the centrifuge lid, wherein one of the holding arm or the holder is arranged on the rotor cover and the other is arranged on the centrifuge lid, wherein the holding arm is detachably and movably mounted in the holder during opening and closing of the centrifuge lid and the holding arm and the holder are spaced from each other by a gap space when the centrifuge lid is closed, wherein the holding arm has a widened head having a joint surface which is designed as form-locking with a joint surface of the holder in such a manner that the holding arm and the holder form a pendulum joint, and further wherein the holder is U-shaped and is open at a side of the holder facing a free end of the centrifuge lid in order to form a removal opening for the holding arm.
2. The centrifuge according to claim 1, wherein one end of the holding arm is arranged on the rotor cover and the other end of the holding arm is arranged in the holder on the centrifuge lid.
3. The centrifuge according to claim 1, wherein the connecting device is arranged at the center of the centrifuge lid and the rotor cover.
4. The centrifuge according to claim 1, wherein the joint surface of the holder is a joint socket and the joint surface of the holding arm is a joint head of a ball joint.
5. The centrifuge according to claim 1, wherein a centering pin is provided which is arranged either on the rotor or at the rotor-side end of the holding arm and which, when the centrifuge lid is closed, engages a complementarily formed channel which is arranged either in the rotor-side end of the holding arm or in the rotor.
6. The centrifuge according to claim 5, wherein the centering pin has a tapering centering surface (16) at a free end of said centering pin.
7. The centrifuge according to claim 6, wherein the centering pin has a rounded centering surface.
8. The centrifuge according to claim 5, wherein said channel is widened towards an end of said channel facing the centering pin.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) The present invention is explained below in greater detail with reference to some exemplary embodiments, which are shown in the figures without restricting the present invention to these exemplary embodiments. In the schematic figures:
(2) FIG. 1 is a sectional side view of a centrifuge in the closed state;
(3) FIG. 2 shows the centrifuge of FIG. 1 in the half open/half closed state;
(4) FIG. 3 shows the centrifuge of FIG. 1 in the open state;
(5) FIG. 4 shows the centrifuge of FIG. 3 from the perspective of an operator looking at the rotor;
(6) FIG. 5 is a perspective sectional view of an embodiment of a holding arm and a holder;
(7) FIG. 6 is a perspective sectional view of another embodiment of a holding arm and a holder;
(8) FIG. 7 is a detail view of an embodiment of a holding arm and a holder;
(9) FIG. 8 is a detail view of another embodiment of a holding arm and a holder;
(10) FIG. 9 is a detail view of sector A of FIGS. 5 and 6;
(11) FIG. 10 is a perspective lateral rear view of a holder; and
(12) FIG. 11 is a perspective side view of the holder of FIG. 10 with released rotor cover.
(13) Like reference numerals designate like elements. Repeatedly shown elements are not designated separately in each drawing.
DETAILED DESCRIPTION OF THE INVENTION
(14) FIG. 1 shows a centrifuge 1 with a housing 23 comprising a centrifuge lid 2. The centrifuge lid 2 is a hinged lid and can be opened or folded open upwardly via the hinge 8. A guard ring 24, which is designed as a burst protection, and a rotor 5 are disposed within the housing 23. Further components that are not shown, such as a drive motor, a cooling compressor and a ventilation system, are also disposed within the housing 23, however these components are of minor importance for the present invention as they do not differ from corresponding prior art devices. The rotor 5 has a receptacle 7 for the drive shaft of the motor (both are not shown). The rotor 5 can be rotated about the axis of rotation 27 by the centrifuge motor. The rotor 5 has a rotor cross 6, a vessel 4 and centrifuge buckets 9 for accommodating sample vessels. Further, a centering pin 10, which will be described in more detail below, is arranged on the rotor 5.
(15) The centrifuge 1 shown in FIG. 1 is in the closed state. That is, the rotor cover 3 rests centrally on the rotor 5. At the center of the rotor cover 3, an end of a holding arm 10 is attached, which protrudes upwardly from the rotor cover and is inserted with its other end in a holder 12 arranged at the center of the centrifuge lid 2. The holder 12 and the holding arm 11 engage each other, however, they are spaced from each other and thus decoupled. The centrifuge 1 is ready for operation, and the rotor 5 could thus be accelerated.
(16) FIGS. 1, 2 and 3 show an opening or closing process of the centrifuge 1. While the centrifuge 1 is closed in FIG. 1, the centrifuge lid 2 shown in FIG. 2 is in a slightly opened or almost completely closed state. The holding arm 11 and the holder 12 are in contact with each other, the rotor cover 3 is lifted off the rotor 5 due to the opening movement of the centrifuge lid 2 and is removed upwardly, or, respectively, is moved towards the rotor 5 due to the closing movement of the centrifuge lid 2 in order to place it in the position shown in FIG. 1. In FIG. 3 and FIG. 4, the centrifuge 1 is shown with completely opened centrifuge lid 2. In FIG. 4, the housing 23 is not shown for reasons of clarity of the illustration. The centrifuge 1 is shown from the perspective of an operator looking at the rotor 5 with its centrifuge buckets 9 for accommodating sample vessels. The rotor cover 3 is suspended via the holding arm 11 from the holder 12 of the centrifuge lid 2. If the centrifuge lid 2 is opened by an operator starting from the closed position shown in FIG. 1, this at first leads to the situation shown in FIG. 2 and then to the situation shown in FIG. 3. The rotor cover 3 follows the movement of the centrifuge lid 2 without any need for the operator to touch the rotor cover 3. If the centrifuge lid 2 is closed starting from the situation of FIG. 3, the stages shown in FIGS. 2 and 1 are passed in reversed order until the rotor cover 3 rests on the rotor 5 and the centrifuge lid 2 is closed. Again, it is not necessary for the operator to touch the rotor cover 3. Instead, the lifting off and placing on the rotor 5 takes place automatically due to the movement of the centrifuge lid 2 and the holder 12 arranged on the centrifuge lid 2 carrying along the holding arm 11 and the rotor cover 3, respectively.
(17) FIGS. 5 and 6 show a perspective sectional view cut through the holder 12 and the holding arm 11, as well as a part of the rotor 5 of the centrifuge 1. The holding arm 11 has a head 13, a body 26 and a base 29. With the base 29, the holding arm 11 is attached to the rotor cover 3. FIGS. 5 and 6 show a situation in which the holding arm 11 and the holder 12 rest against each other and the rotor cover 3 is suspended from the centrifuge lid 2 (which is not shown in FIGS. 5 and 6) via the holding arm 11 and the holder 12. The holding arm 11 engages the holder 12 and rests with its head 13 on the rail 28 of the holder 12. According to FIG. 5, the head 13 specifically has the shape of a truncated cone and rests with its lateral surface, the joint surface 17, on the joint surface 18 of the holder 12. Depending on the relative angle between the holding arm 11 and the holder 12, the support of the joint surface 17 on the joint surface 18 occurs as a two-point or as a three-point support. The joint surfaces 17, 18 together form the pendulum joint 19, via which the rotor cover 3 is connected with the centrifuge lid 2.
(18) FIG. 6 shows an alternative embodiment, in which the head 13 is shaped as a spherical cap and rests with its rounded lateral surface, which represents the joint surface 17, on the joint surface 18 of the holder 12. The joint surface 18 is formed in a complementary fashion to the spherical joint surface 17 and forms a joint socket. The two joint surfaces 17, 18 form a pendulum joint 19, which according to FIG. 6 is arranged as a ball joint and thus allows for a particularly precise swinging movement of the rotor cover 3 relative to the centrifuge lid 2 and the rotor 5. The detachable connection between the centrifuge lid 2 and the rotor cover 3 is closed in FIGS. 5 and 6. The rotor cover 3 is suspended with its entire weight from the centrifuge lid 2 via the pendulum joint 19, 19. If the centrifuge lid 2 is further closed or opened, the rotor cover 3 follows the movement of the centrifuge lid 2.
(19) FIGS. 7 and 8 show the position of the holding arm 11 relative to the holder 12 when the centrifuge lid 2 is completely closed. The detachable connection between the centrifuge lid 2 and the rotor cover 3 is detached. In the situation shown, the rotor cover 3 rests on the rotor 5. For reasons of visibility, the centrifuge lid 2 is not shown. The holding arm 11 is spaced from the holder 12 via a gap space 21. The gap space 21 is composed of a vertical projection 22 and a horizontal spacing 25. The vertical projection 22 is achieved by an excess length of the holding arm 11, in particular, of the body 26 of the holding arm 11. The horizontal spacing 25 is created by the holding arm 11, in particular, the body 26 of the holding arm 11, being thinner than the central recess of the U-shaped holder 12. The holding arm 11 is thus spaced from the holder 12 both horizontally as well as vertically via the gap space 21. This allows for the holding arm 11 to rotate together with the rotor 5 and the rotor cover 3 resting thereon during the operation of the centrifuge 1, without the holding arm 11 colliding, or making otherwise contact, with the holder 12.
(20) FIGS. 7 and 8 further show the rail 28 of the holder 12, which narrows the area between the two U-arms of the holder 12 in such a way that the widened head 13 of the holding arm 11 engages behind the rail 28, and an opening of the centrifuge lid 2 and an essentially vertical lifting of the holder 12 will result in the joint surfaces 17, 17 of the head 13 and the joint surfaces 18, 18 of the holder 12 abutting each other. Due to the folding movement of the centrifuge lid 2 and the weight of the rotor cover 3, the latter is pulled towards the closed side of the U-shaped holder when the centrifuge lid 2 is opened. The head 13 of the holding arm 11 is larger than the opening of the U-shaped holder 12, which is delimited by the rail 28 and faces away from the centrifuge lid 2. The holding arm 11 is thus suspended in the holder 12 and cannot by itself slip out of the holder 12 during opening or closing of the centrifuge 1.
(21) FIG. 9 is a detail view of sector A of FIGS. 5 and 6 and shows an enlarged sectional view of the rotor-side end of the holding arm 11 with a centering device according to the present invention. A channel 14 is provided inside the body 26 of the holding arm 11, in which channel a centering pin 10 can be inserted which is arranged on the rotor 5. The channel 14 completely extends through the holding arm 11 from one end to the other. However, it is also possible for the channel 14 to only extend through a part of the holding arm 11, so that the channel 14 has a blind end in the holding arm 11. In the shown exemplary embodiments, the holding arm 11 penetrates the rotor cover 3 with its base 29. However, it is also possible to arrange the holding arm 11 only on one side of the rotor cover 3. In this case, the channel 14 likewise extends through the rotor cover 3 or is arranged on the rotor 5, while the centering pin 10 is arranged on the rotor cover 3.
(22) FIG. 1 shows the centering pin 10 when inserted in the channel 14. By inserting the centering pin 10 in the channel 14, the rotor cover 3 is aligned centrally above the rotor 5 and placed on the rotor 5 in the correct, i.e., intended position. FIGS. 5, 6 and 9 show the situation shortly before insertion of the centering pin 10 in the channel 14. At its end facing the centering pin 10, the channel 14 has a widened section 15. This widened section 15 has the shape and the function of a funnel, which is to guide the centering pin 10 into the channel 14 even if the rotor cover 3, or the holding arm 11, respectively, is not positioned exactly above the centering pin 10. The exact positioning of the rotor cover 3 relative to the rotor 5 is achieved by arranging the channel 14 as complementary to the centering pin 10 and having a diameter that corresponds to the diameter of the centering pin 10 in such a way that the centering pin 10 closely slides along the inner surface of the channel 14 during the placing of the rotor cover 3 on the rotor 5. In this manner, the rotor cover 3 is positioned, or centered, on the rotor 5.
(23) In order to further simplify the insertion of the centering pin 10 in the channel 14 and, in particular, to prevent wedging and jamming, the centering pin 10 has a centering surface 16 at its free end, with which it enters the channel 14. The centering surface 16 constitutes a rounded section of the centering pin 10 and slides along the funnel-shaped surfaces of the widened section 15 of the channel 14. In this manner, a precise centering and a safe closing of the rotor 5 is achieved even if the rotor cover 3 is not positioned exactly above the rotor.
(24) FIGS. 10 and 11 show the option of removing the rotor cover 3 from the centrifuge lid 2, which is shown as transparent in FIGS. 10 and 11 for reasons of illustration, by an operator via the removal opening 20 on the open side of the U-shaped holder 12. For this purpose, an operator merely needs to lift the rotor cover 3 in the direction of the free end of the centrifuge lid 2. The widened head 13 of the holding arm 11 is guided along, or past, the rail 28 of the holder 12 until the holding arm 11 is disengaged from the holder 12 and can be removed therefrom. The rotor cover 3 and the surface of the centrifuge lid 2 with the holder 12 can then be cleaned. To reattach the rotor cover 3 on the centrifuge lid 2, the holding arm 11 is merely suspended in the holder 12 by proceeding in reversed order.
(25) While the present invention has been illustrated by description of various embodiments and while those embodiments have been described in considerable detail, it is not the intention of Applicant to restrict or in any way limit the scope of the appended claims to such details. Additional advantages and modifications will readily appear to those skilled in the art. The present invention in its broader aspects is therefore not limited to the specific details and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of Applicants invention.
