COUPLING DEVICE FOR COUPLING AN OBJECT, ESPECIALLY A SEAT OR TABLE DEVICE, WITH A FIRST AND A SECOND HOLDER

Abstract: A coupling device for coupling an object (2), especially a seat or table device, with a first and/or a second holder (20, 25). The coupling device comprises a coupling member (1) on the object and locking means (4) for locking the coupling member to the first and/or the second holder. One holder (25) is sleeve-shaped and the other holder (20) is pin-shaped. The coupling member consists of a coupling sleeve (1) having a central bore, and the pin-shaped holder (20) can be locked in the central bore of the coupling sleeve (1) while the sleeve-shaped holder (25) can be locked at the outer side of the coupling sleeve (1).

Description: COUPLING DEVICE FOR COUPLING AN OBJECT, ESPECIALLY A SEAT OR TABLE DEVICE, WITH A FIRST AND A SECOND HOLDER The present invention relates to a coupling de¬ vice for coupling an object, especially a seat or table device, with a first and/or a second holder, comprising a coupling member on the object and lock- ing means for locking the coupling member to the first and/or the second holder, one holder being sleeve-shaped and the other holder pin-shaped. The invention relates more particularly to a coupling device for the automa¬ tic coupling of a seat or table device with a holder on a first implement and simultaneous automatic re¬ lease of the object from a holder on a second imple¬ ment, and conversely. When, e.g. in the care in a hospital, a bedridden patient is to have a bath, it is desirable to be able to avoid first having to transfer the patient from the bed to a transport carriage having a supporting table or stretcher and a wheeled chassis, and thereafter to another table that can be sunk into the bath by means of a lifting device. To this end, the patient- supporting table, the wheeled chassis and the lifting device are so devised that the same table can be mounted on and dismounted from both of these implements. This means that the handling of the patient is considerably facilitated since it is easier to transfer a table with a patient thereon than the patient alone. In order to obviate the risk of the table loosening or tilting in an uncontrolled manner during such trans¬ fer, the table must be locked all the time to at least one of the implements, which means that it must be locked to the second implement before being released from the first. Present-day devices for the optional coupling of a patient-supporting table or a stretcher with different implements therefore often comprise two separate locking means, one for each implement, which implies a rather complex and, hence, expensive con¬ struction. Another drawback of these coupling devices is that they are all operated manually, for instance by means of operating levers which are often disposed underneath the table or stretcher. Thus, during the entire transfer of the table from one implement to the other an attendant must bend below the table in order to be able to operate the levers. This is not a particularly suitable working position considering that the person attending to the transfer should pre¬ ferably be able to keep an eye on the patient during the entire transfer operation so as to be able to obviate any tendency of unintentional loosening or tilting of the table, and considering the ergonomic aspect.. US-A-3,631,546 discloses a device for the optional coupling of a stretcher with different implements. This prior art coupling device offers the advantage over other known coupling devices of having a common locking means for both implements. This locking means consists of'transverse cylinders which are mounted on the stret¬ cher and one of which is eccentrically rotatable, i.e. the distance between the cylinders can be varied, and of recesses in the implements for the cylinders. The recesses are arranged on the outer and inner sides of the implements. When the eccentric cylinder is rotated in one or the other direction by means of an operating lever, the cylinders will alternatively lock one or the other implement to the stretcher as at the same time this is released from the implement that was locked to the stretcher before the transfer was commenced. This means that this coupling device, despite its single locking means, is of a rather complicated construction. Also, it is doubtful whether it actually ensures that the release and the locking of the stret- cher with respect to one or the other implement can be carried out in a single operation without any un¬ stable intermediate position, since the eccentric cylinder in the intermediate position is resting only against the outermost edge of the recess of the respec- tive implement that is located beside this cylinder. Also, the coupling device is operated manually by means of an operating lever provided underneath the stretcher. One object of the present invention is to pro- vide a coupling device which is of a simple and re¬ liable construction and, thus, will be inexpensive to manufacture and have long service life. Another object of the invention is to provide a coupling device which ensures a completely safe transfer of an object, particularly a seat or table device, from a first holder to a second holder, and conversely. Yet another object of the present invention is to provide a coupling device which permits automatic (and not manual) coupling of an object with a first holder and simultaneous automatic release of the object from a second holder, and conversely. These and other objects of the invention are achiev¬ ed if the device of the type mentioned in the introduc- tion to this specification is given the features appear¬ ing from the main claim. The subclaims state particular¬ ly preferred embodiments of the invention. The invention will be described in greater detail hereinbelow with reference to the accompanying drawings. Fig. 1 is a cross-section of the coupling device accord¬ ing to the present invention. Fig. 2 illustrates the coupling device of Fig. 1 when coupling a supporting table with a piston rod on a chassis. Fig. 3 shows the coupling device of Fig 1 when coupling the table with the piston rod and with the lifting arm of a lifting device. Fig. 4 is a cross-section taken along the line IV-IV in Fig. 3. Fig. 5 shows the coupling device of Fig. 1 when only coupling the table with the lifting arm. Fig. 6 is a cross-section taken along the line VI-VI in Fig. 5, and Fig. 7 shows from above a locking bolt included in the coupling device of Fig. 1 when engaging the lifting arm. The coupling device shown in Fig. 1 consists of a coupling sleeve 1, a locking pin 3 and a locking bolt 4 which consists of a body 40 having a through slot 41 of rectangular cross-section (Fig. 7). The coupling sleeve 1 has a central through bore and is fixedly connected e.g. to a patient-supporting table 2. As appears from the Figure, the coupling sleeve 1 has three portions of different outer and inner dia- meters, of which the upper portion 5, which is located adjacent the underside of the table 2, has a constant outer diameter and an inner diameter which is constant closest to the table but thereafter progressively increases in a direction away from the table. This portion further has a horizontal through bore 8 ex¬ tending transversely through the entire coupling sleeve 1. The locking pin 3 is fixedly mounted in the bore 8 such that its free outer end extends a certain distance into the central bore of the coupling sleeve. The intermediate sleeve portion 6 has an inner diameter which progressively increases in a direction away from the table and an outer diameter which de¬ creases in the same direction. The lower portion 7 of the coupling sleeve 1 however has a constant inner diameter and an outer diameter which progressively increases in a direction towards the table. This por¬ tion is further provided with a circumferential groove 5 9 extending around the entire outer periphery of the portion 7. A through bore 10 extends from the bottom of the groove 9. The bore 10 also communicates with an axial recess provided in the wall of the coupling sleeve 1 and extending from the upper end of the sleeve downwards to the bore 10. A T-shaped rocker 12 is pivotally mounted in the coupling sleeve 1 by means of a journal 13 in such a manner that its web 14 extends through the axial recess 11 downwards into the slot 41 of the locking bolt 4 while its flange 15 partially extends through the horizontal bore 8. The flange 15 is so arranged in the bore 8 that its outwardly facing end projects a certain distance from the outer face of the coupling sleeve 1 while its inwardly facing end is located approximately in the middle of the central bore of the coupling sleeve 1. The outwardly facing end of the flange 15 is provided on its side facing away from the table 2 with a set screw 16 whose head can be positioned at a predetermined distance from the flange 15. The inwardly facing end of the flange 15 is provided on its side facing away from the table 2 with a compression spring 17 the free end of which extends a certain distance downwards in the central bore of the coupling sleeve 1. The web 14 of the rocker 12 is pivotally connected at its free end to the locking bolt 4 by means of a journal 18. As appears from the Figure, the locking bolt 4 is movable in the through bore 10 which serves as a guide for the locking bolt. The locking pin 3 fixedly mounted in the bore 8 is disposed on the opposite side of the central bore of the coupling sleeve 1 with respect to the rocker 12. The table 2 has a through bore above the rocker 12 so as not to prevent the pivotal movement of the rocker about the journal 13. It further ap¬ pears from the Figure that the rocker 12 on its journal 13 has a spring 19 tending to pivot the rocker clockwise, whereby the locking bolt 4 is urged outwards in the bore 10, and that this pivotal movement is limited by an abutment 30. Fig. 2 shows the coupling device when a piston rod 20 on a wheeled chassis (not shown) is locked in the coupling sleeve. In the outer face, the piston rod 20 has a groove 21 for receiving the locking bolt 4, and at the upper end a groove 22 extending across its entire width, for receiving both the flange 15 of the rocker 12 and the locking pin 3, and a central, axially conical bore 23 for receiving the compression spring 17. It further appears from the Figure that the upper end portion of the piston rod 20 is upwardly tapering and that the outer diameter of this end portion con¬ forms to the inner diameter of the upper portion of the coupling sleeve 1, which entails that there is no play between the table 2 and the piston rod 20 when the piston rod is locked to the coupling sleeve. Nor can the piston rod rotate in this position, since both the locking pin 3 and the locking bolt 4 lock the piston rod 20 against rotation relative to the coupling sleeve 1. It should also be pointed out that the locking pin 3 is not necessary for locking the piston rod, but that it extends the life of the lock¬ ing bolt 4 by reducing the loads which would other¬ wise act thereon. In this coupling position, the rocker 12 is af- fected both by the spring 19 and the compression spring 17 acting so as to pivot the rocker clockwise and anticlockwise, respectively. Since the spring tension of the compression spring 17 exceeds that of the spring 19, the rocker will pivot anticlockwise until the web 14 of the rocker 12 abuts the upper edge of the internal slot 41 of the locking bolt 4. This position of the rocker 12 is referred to in the following as the left-hand end position of the rocker. In this position, ( the locking bolt 4 only engages with the groove 21 on the outer face of the piston rod 20. Fig. 3 shows the coupling device with the coup- ling sleeve 1 and, thus, the table 2 locked to both the piston rod 20 and a lifting arm 25 on a lifting device (not shown). As appears more clearly from Fig. 7, the lifting arm 25 is provided at its free end with two fork shanks 26, 27 which in the position shown in Fig. 3 engage around the coupling sleeve 1. These fork shanks have an internal groove 28 for receiving the locking bolt 4. In this coupling position, the rocker 12 is acted on both by the spring 19 and the compression spring 17, but cannot pivot through such a large angle anticlockwise as in Fig. 2 since the head of the set screw 16 abuts on the upper end surface of the fork shank 27 before the rocker reaches its end position in the anticlockwise direction. In this position of the rocker, the locking bolt engages both with the groove 28 in the fork shanks 26, 27 and with the groove 21 on the outer face of the piston rod 20. Fig. 4 illustrates that stated above, namely that the journal 13 of the rocker 12 is mounted in the coupling sleeve 1, that the lower end of the web 14 of the rocker 12 is located in the slot 41 in the locking bolt 4, and that the locking bolt 4 is pivotal¬ ly connected to the web 14 by means of a journal 18. The hole provided in the web 14 for receiving the journal 18 is oval, which means that there is a certain play between the journal and the web in the longitu¬ dinal direction thereof. Fig. 5 shows the coupling device with only the lifting arm 25 locked to the coupling sleeve 1. In this coupling position, the rocker 12 is acted on only by the spring 19 which loads the rocker for pivot¬ ing clockwise until the free end of the web 14 engages 8 the body 40 of the locking bolt 4. In the following, this position of the rocker 12 will be referred to as the clockwise end position of the rocker 12. It further appears from the Figure that the lock- ing bolt 4 in this coupling position is not pressed against the boundary surfaces of the groove 28, which means that the lifting arm 25 can be rotated about the coupling sleeve 1. From Fig. 6 appears that the free end of the compression spring 17 is located just below the lower edge of the bore 10 when the rocker is in its clockwise end position, and that the bore 10 has circular cross- section. Fig. 7 shows an embodiment of the locking bolt 4, in which the body 40 of the locking bolt consists of a cylindrical part 42 and an arcuate flange 43. As appears from the Figure, the flange 43 engages with the groove 28 in the fork shanks 26, 27 of the lifting arm 25, while the free end of the cylindrical part 42 is intended to engage with the groove 21 in the outer face of the piston rod 20. Since the locking pin 4 engages the lifting arm 25 with an engagement surface having a greater longitudinal extent than the spacing between the free outer ends of the fork shanks 26, 27, the coupling sleeve 1 and, hence, the table 2 can be rotated relative to the lifting arm 25 without any risk of the locking bolt being released from the groove 28. This possibility of rotation makes it easier to bring the table into the desired posi- tion. The function of the coupling device will now be described with reference to Figs. 2, 3 and 5. When a table 2 with a patient lying thereon should be trans¬ ferred from the piston rod 20 of a wheeled chassis, see Fig. 2, to the lifting arm 25 of a lifting de¬ vice for placing the table e.g. in a bath, the fork shanks 26, 27 of the lifting arm are first moved in- wards towards the piston rod 20 to a position just below the coupling sleeve 1. The piston rod 20 is thereafter lowered together with the coupling sleeve 1 locked thereto, by means of a lifting and lowering device mounted on the chassis, downwards towards the lifting arm 25. Since the inner surface of the lifting arm 25 and the outer surface of the coupling sleeve 1 both are frustoconical, the coupling sleeve is easily guided into the lifting arm. When the coupling sleeve 1 has been introduced a certain distance in the lifting arm 25, the set screw 16 on the flange 15 of the rocker 12 will come in contact with the upper end surface of the fork shank 27, whereupon a certain lifting force is trans- mitted to the rocker 12 by means of the set screw 16 from the lifting arm 25, which lifting force acts so as to pivot the rocker clockwise. The rocker 12 is also acted on by the spring 19 and the compression spring 17 tending to pivot the rocker clockwise and anticlockwise, respectively. Since the lifting force from the lifting arm 25 and the spring 19 together act on the rocker with a larger force than the spring 17, the rocker will be pivoted clockwise until the spring tension of the spring 17 - which force increases during the pivotal movement of the rocker since the spring 17 is compressed in the bore 23 of the piston rod 20 when the rocker pivots clockwise - becomes equal to the total force of the spring 19 and the lifting arm 25. The rocker 12 will then occupy the stable intermediate position shown in Fig. 3. In this intermediate position, the locking bolt 4 engages both with the groove 28 in the lifting arm 25 and the groove 21 on the outer face of the piston rod 20, the coupling sleeve and, thus, the table 2 being locked both to the lifting arm 25 and the piston rod 20. The pivotal movement of the rocker 12 clockwise would not have been possible if the inwardly facing end of the flange 15 had engaged the piston rod 20 directly and not via the spring 17. When the piston rod 20 and the coupling sleeve 1, still locked thereto, are further lowered towards the lifting arm 25, the coupling sleeve will be further moved a certain distance downwards in the lifting arm until the play between their surfaces has been completely eliminated. The upper end surface of the fork shank 27 will at the same time be urged still harder against the set screw 16 until the lifting force of the lifting arm 25 on the rocker 12 becomes so great as to be able, together with the force of the spring 19, to counteract the action of the spring 17, such that the rocker will again start pivoting clockwise about the journal 13. The locking bolt 4 is thus brought out of its engagement with the piston rod 20, whereby the coupling sleeve 1 will be disengaged from the piston rod 20 when this is further lowered, and in this position, the coupling sleeve 1 thus is locked only to the lifting arm 25, see Fig. 5. When the table 2 should instead be transferred from the lifting arm 25 to the piston rod 20 on the wheeled chassis, the piston rod is first moved from below up into the central bore of the coupling sleeve 1. The introduction of the piston rod in this central bore is facilitated in that both the piston rod and the central bore are frustoconical, which means that it is possible to have a play-free connection between the piston rod and the central bore of the coupling sleeve when the piston rod is locked to the coupling sleeve. At the same time, a relatively large play is obtained between their mutually facing surfaces at the beginning of the introduction of the piston rod. The compression spring 17 of the rocker 12 is introduced in the bore 23 in the upper end of the piston rod 20 when the piston rod is introduced in the central bore, the former introduction process being facilitated in that the bore 23 is conical. Further introduction of the piston rod 20 in the coup¬ ling sleeve 1 of course entails that the compression spring 17 is compressed, such that its tension will progressively increase. When this spring tension exceeds that of the spring 19, the rocker will pivot anticlock¬ wise about the journal 13 until the head of the set screws 16 engages the upper end surface of the fork shank 27, see Fig. 3. This pivotal movement of the rocker 12 entails that the locking bolt 4 is also moved into engagement with the groove 21 on the outer face of the piston rod 20, and the coupling sleeve is thereafter locked both to the lifting arm 25 and the piston rod 20. The engagement of the set screw 16 against the fork shank 27 prevents all further pivotal movement of the rocker 12 until the piston rod 20 comes into mechanical contact with the rocker 12 and starts lifting the rocker and its set screw 16 from the lifting arm. The spring 17 may then again pivot the rocker 12 anticlockwise, such that the locking bolt 4 is brought out of its engagement with the groove 28 in the lifting arm 25. When the piston rod is further raised, it will move, together with the coupling sleeve locked there- to, upwardly in relation to the lifting arm, and when the entire coupling sleeve has been moved away from the lifting arm 25, this can be removed from the piston rod 20. It is obvious that the invention is not restricted to the embodiment described above and shown in the draw¬ ings, but may be modified in several different ways within the spirit and scope of the accompanying claims. For instance, the table may be replaced by a chair to be transferred from a wheeled frame e.g. to a lifting device.

Claims: CLAIMS 1. A coupling device for coupling an object (2), especially a seat or table device, with a first and/or a second holder (20, 25), comprising a coupling member (1) on said object and locking means (4) for locking the coupling member to said first and/or second holder, one holder (25) being sleeve-shaped and the other holder (20) pin-shaped, c h a r a c t e r i z e d in that the coupling member comprises a coupling sleeve (1) having a central bore, and that the pin-shaped holder (20) can be locked in the central bore of the coupling sleeve (1) while the sleeve-shaped holder (25) can be locked at the outer side of the coupling sleeve (1) . 2. Coupling device as claimed in claim 1, c h a - r a c t e r i z e d in that the locking means (4) is mounted on a rocker (12) on the coupling member (1), said rocker being pivotal between two end posi¬ tions in order to bring the locking means into locking engagement with one or the other of said holders (20, 25) and yieldingly biased towards one end position, and having two actuating means (17, 16) which are so arranged on the rocker (12) as to come into contact with the respective holder (20, 25) when the holder is caused to engage the coupling member (1) during the coupling operation, and to pivot the rocker from one end position to the other, whereby the locking means (4) is brought into engagement with the holder engaging the coupling member. 3. Coupling device as claimed in claim 2, c h a - r a c t e r i z e d in that the rocker (12) is T-shaped and that the free end of its web (14) is pivotally connected to the locking means (4) by means of a jour¬ nal (18), while its flange (15) is so arranged in the coupling sleeve (1) that one end thereof projects a predetermined distance from the outer side of the coupling sleeve while the other end is located in the central bore of the coupling sleeve. 4. Coupling device as claimed in claim 3, c h a - r a c t e r i z e d in that the actuating means of the rocker (12) comprise a compression spring (17) which is so mounted on the end of the flange (15) which is located in the central bore of the coupling sleeve (1) that it extends a predetermined distance downwards into said central bore so as to come into contact with the pin-shaped holder (20) when this is introduced in the central bore of the coupling sleeve (1), and a set screw (16) which is provided on the end of the flange (15) projecting from the outer side of the coupling sleeve (1), and adapted to come into contact with the sleeve-shaped holder (25) when this is applied to the coupling sleeve (1). 5. Coupling device as claimed in any one of claims 1-4, c h a r a c t e r i z e d in that the locking means comprises a locking bolt (4) which is displaceably mounted in a hole (10) provided in the wall of the coupling sleeve (1) and serving as a guide for the locking bolt (4) .

Inventors: SANDELL ANDERS LENNART, SANDELL, ANDERS, LENNART
Applicants: ARJO HOSPITAL EQUIPMENT AB
Application year: 1986
Main classification: A61G7
IPC codes: A61G7