An actuator system

[0001] The invention relates to an actuator system having at least one arrangement for an electrical plug, the arrangement comprising a socket and a rotatable union nut in connection therewith, the union nut having a hole for inserting the plug into the socket.

[0002] Low voltage plug connections are widely used in connection with apparatus, equipment and installations and are well known. Examples of plugs that are typically used for adjustable furniture parts with actuator systems include the conventional "Jack" or DIN type connector and the more modern type Minifit (trademark of Molex). Plugs are usually fastened only in combination with socket clamp connectors. The plug can thus be relatively easily inserted into the socket, but it also has the disadvantage that it may accidentally fall out completely or partially. This can e.g. happen when the bed is transported over an uneven surface or when the cord gets caught in something. Sometimes it is desirable and sometimes required that the plug cannot be easily removed. If it is an electrically adjustable bed, it is very uncomfortable for both the user of the bed and the nursing staff, when the plug falls out and the bed loses some of its functionalities, e.g. such that the surface of the bed to rest cannot be adjusted. This also causes additional effort for service personnel who must solve the problem. In the worst case this can be fatal e.g. when the bed with a patient who is shocked cannot be leveled with the horizontal resting surface. If the plug is not attached to the socket in the housing, there is an additional risk that water and disinfectants may enter the housing during cleaning and damage the electronics and plug connections. It is possible that damage will not occur immediately, but may later develop into e.g. inexplicable interrupts or failure of the control unit. Document EP 0 660 452 for LINAK A / S discloses a union nut having locking means for the plug, the union nut being divided into two parts in which the first part forms an almost closed circle and the second part serves to close the circle and surround the plug and locking it on the locking pin on the housing. This solution is applicable, but nevertheless not very practical, as the connecting nut must be mounted after inserting the plug into the socket and is therefore blocked by the insertion of the locking mechanism. Since cable assembly is often carried out when the control unit or actuator is mounted on a piece of furniture, this causes a lot of time-consuming inconvenience. In addition, there is the possibility that many components may get lost, causing them to not be mounted, resulting in known defects. The object of the invention is to provide an easy solution to the problem outlined.

[0003] This is achieved according to the invention by the structure of an actuator system having at least one arrangement for an electric plug, the arrangement comprising a socket and a rotatable

-2 connecting nut in connection with the socket, and wherein the connecting nut has a hole for inserting the electric plug into said socket, whereby the cross-sectional shape of the electric plug in the area close to the connecting nut and the shape of the opening in front of the connecting nut are adapted such that that when the union nut is turned to: i) the non-operating position, the shape of the hole in the connecting nut compared to the shape of the cross-section of the electric plug is such, that the electric plug can be easily inserted and removed from the socket, and ii) a locked position, in which the shape of the opening in front of the coupling nut compared to the shape of the cross-section of the plug in the area close to the coupling nut is such, that the union nut makes it difficult to insert and remove the electrical plug, and in which the union nut in its locked position is blocked by a spring leg formed close to the socket, and the spring leg, which by meshing with the groove in the side wall of the connecting nut prevents the connecting nut from turning back to the non-functional position. In this way, a solution to the problem outlined is provided so that the plug can be retained in its position in the socket and in addition the means enabling this, in the form of a connecting nut, are mounted in the socket and therefore cannot get lost. In addition, difficult assembly work has been eliminated as the only requirements are that the plug is inserted and the union nut is turned to the locked position.

[0004] The union nut is further protected against unintentional rotation back to the non-functional position by a spring leg meshing with the groove. With a simple tool, the pin can be activated through a hole in the side wall of the union nut, which is located where the groove is provided on the inside of the side wall of the union nut and the union nut is turned back, after which the plug can be pulled out.

[0005] An embodiment of the locking mechanism for holding the plug in the socket according to the invention is particularly easy and user-friendly, since the locking mechanism in the form of a coupling nut is mounted on the housing socket before the plugs are inserted. In the housing in the socket hole, the socket is expanded like a neck, which is formed with the sleeve downwards, on which the connecting nut is latched. On the inner diameter, the union nut is fitted with a corresponding sleeve that fits with the neck sleeve. The two sleeves thus form cooperating means of the locking latch. After snapping together, the union nut is kept engaged with the neck. Therefore, there are no loose parts that can get lost.

[0006] A difficult assembly method is eliminated for the same reason, as the plug must be inserted through the opening in front of the coupling nut, after which the coupling nut is rotated to the locked position and locks the plug before removing from the socket. The opening on the front of the coupling nut is adapted to the plug profile so that it can be inserted in front of the coupling nut. If the union nut is in the unlocked position, the mechanical coding of the plug corresponds to the mechanical coding that is provided in the socket. Similarly, in this position, the plug matches the coding of the electrical socket, therefore the plug can be fully inserted to form a connection

-3 electric between plug and socket. When the plug is inserted at a height corresponding directly below the bottom of the connecting nut front, there is a narrowing of the plug cross section, at least in the large radius of what corresponds to the narrow cross section radius of the plug. When the union nut is turned, the narrow hole radius in front of the union nut will cause the union nut to lock the plug on the wide cross-sectional radius of the plug. This arrangement further ensures that the plug will have to be fully inserted before it can be locked into the socket by the means of the connecting nut. If it is desired that the union nut locks the plug against movement in both directions, the plug may be equipped with another sleeve that lies opposite the front of the union nut on its outer side and therefore prevents the plug from being pushed further into the socket. In another embodiment, the union nut may be provided with a double front with an intermediate space for the plug sleeve, in which the union nut will then block the plug from moving both from and further into the housing. This arrangement will protect the electrical plug connection from damage caused by collision of the plugs.

[0007] Even if the locking mechanism for retaining the plug in the socket is described here as a part that is mounted on the tubular neck and can rotate around it, there is nothing to prevent the locking mechanism from being constructed in such a way that it includes a plug mounted in the socket and kept in the socket. Such a plug is used to seal a socket that is not in use and therefore protects the electronics and plug connections against the ingress of liquid or dust. The sealing plug may be provided with the locking mechanism described above in which the union nut is pivoted between the locked position and the unlocked position such that the sealing plug is held in the socket in the locked position. The sealing plug is also held in position such that, in the same way as for a connecting nut of this type, which locks the plug in the socket, it is equipped with cooperating means of the locking latch in relation to the equivalent configured in the socket. As described above, they can be a locking latch means in the form of a sleeve. By minimizing the mutual locking force of the locking latch means, it is ensured that the sealing plug can be removed if desired later to insert the plug into the socket.

[0008] In a particularly simple embodiment, the union nut for locking the plug can be held in position at the entrance to the socket and can receive the plug constructed as a sealing plug. The sealing plug is intentionally constructed in the same way as the electrical plugs used, at the end that disappears in the socket and is generally constructed ensuring that the socket is effectively protected against the ingress of liquid or dust. It is preferred that the plug is equipped with a strap or the like that can be gripped when the sealing plug is to be removed in order to make room for another plug to insert into the socket.

[0009] Furthermore, it is preferred that the plug is fitted with a seal, e.g. "O" sealing ring, which is a seal between the plug and the socket, preventing liquid or dust from entering. This embodiment will also contribute to holding the plug in the socket regardless of whether it is or is not blocked by the union nut, especially if somewhere in the longitudinal direction of its tubular extension the socket is equipped with a groove that is intended for receiving and positioning the ring "O" sealing on the plug. If a plug is used as a sealing plug without a wire connection, then the connection between the tubular shape of the socket and the O-ring of the sealing plug will in most cases be sufficient to ensure that the sealing plug is held in the socket even if locking with the union nut is preferred.

[0010] The locking system for holding the plug in the socket can be implemented in conjunction with a housing for a linear electric servomotor, but can also be used in housings for control units, indicator boxes, regulators, power supplies and housings with other types of electrical equipment that is used in the actuator system.

[0011] An embodiment of the actuator system according to the invention will be described in more detail below with reference to the attached drawing, in which:

FIG. 1 shows an electric actuator having a socket and a union nut, Fig. 2 shows a housing part with a socket and a union nut for holding a plug with a detailed view of the socket with a plug, fig. 3 shows a detailed view of the coupling nut, fig. 4 shows a part of the housing with a detailed view of the sleeve on the socket and the locking pin, fig. 5 shows a part of the housing with a socket and a union nut, fig. 6 shows the electric plug seen from one end, fig. 7 shows the Minifit plug, fig. 8 is a top view of the plug in the socket with the union nut in the locked position, fig. 9 shows a part of the housing with a detailed cross-sectional view of the plug in the socket with the union nut in the locked position, fig. 10 shows a housing with sockets equipped with union nuts for holding the plug, fig. 11 shows an example of a cross-section of a hole in a connecting nut, Fig. 12 shows another example of a cross-section of a hole in a connecting nut, and Fig. 13 shows a third example of a cross-section of a hole in a connecting nut.

-5. 1 the drawing shows an electrically controlled actuator 1 consisting of a housing 2 and an activation element in the form of a tubular rod 3 on which a front handle 4 for assembling the actuator into a mechanical structure with a movable part is mounted, e.g. hospital or care bed. The other end of the cylinder 1 is equipped with a rear handle 5 that is connected to another part of the mechanical structure. If, via a gearbox, the controller motor drives the spindle relative to the spindle of the nut connected to the activation element and secured against rotation, the actuator will be able to adjust the moving part of the mechanical structure.

[0013] As can be seen in Fig. 2 of the drawing, a part is shown, namely the rear end of the housing 2 for an actuator equipped with a socket 6 for receiving an electric plug 7. Surrounded by the hole and above the neck of the socket, there is a connecting nut 8 having a locking mechanism for locking the plug 7 into position in the socket 6 so that it cannot be easily pulled out.

[0014] At the front, the union nut 8 is provided with a hole 9 with a geometric shape corresponding to the external geometric shape of the plug, such that the plug 7 can pass through the hole 9 in the union nut 8 and into the socket 6. On the connecting nut 8, a sleeve 10 is provided on the inside of the perimeter over the entire perimeter of the perimeter, but interrupted by two sections 11. A pin 12 is provided on the edge of the socket. The pin 12 has a design that allows it to lock into one of the sections 11 of the connecting nut, which is free of the sleeve 10. The seat 6, which is tubular, is extended to the outside of the housing and thus forms a neck 13, the outer side of which is provided with a sleeve 14, which serves as a stop for the connecting nut 8 in the vertical direction when the connecting nut is latched on the neck 13. The sleeve 14 on the neck 13 and the sleeve 10 on the inside of the coupling nut 8 thus serve as cooperating means of a locking latch that lock the parts together. The union nut 8 can rotate freely on the neck 13 around the hole in the socket, but it is locked against rotation when the pin 12 on the edge of the socket 6 is engaged with a corresponding locking mechanism in the form of the section 11 of the union nut 4.

[0015] Fig. 5 shows how the union nut 8 is latched onto the neck 13 on the socket. It is easy to see that the sleeve 14 on the neck and the sleeve 10 on the inside of the coupling nut form cooperative locking latch means that prevent the coupling nut from falling out of the socket. The means of the locking latch are dimensioned to have a locking force that is so great that a jerk on the plug 7 will not separate the coupling nut from the socket so that the plug and coupling nut cannot fall out. Since the side wall of the coupling nut is constructed with a double wall, it requires less force to engage the locking latch means with each other, since less material will have to be deformed when the coupling nut is latched onto the neck 13 of the socket 6. An additional detail that appears in Fig. 5 is that there is mechanical coding 18a in the socket for correctly positioning the plug 7 in the socket 6. The counterpart in the form of a recess 18 running in the longitudinal direction of the plug establishes the corresponding coding on the plug, as appears in Fig. 6 and 7. Even

The connecting nut is turned to the locked position and the plug is turned so that it can be inserted through the hole 9 in front of the connecting nut 8, however, it is still not possible to insert the plug 7 into socket 6.

[0016] If it is desired to seal the seat that is not in use and thus protect the housing against liquid or dust, the sealing plug can easily be mounted in the seat and locked before removal by the union nut. The sealing plug may be a blind plug. In another embodiment, not shown, the union nut is formed on the plug. The locking latch means in the form of sleeves 10, 14, which ensure that the union nut 8 is secured on the socket 6, should be adjusted here so that the plug is secured, but can also be removed if it is desired to insert the plug 7 into the socket . The union nut having a built-in sealing plug can intentionally be rotated to lock to keep it securely in its seat.

[0017] The plug used and shown in Fig. 7 is a Minifit type electric plug in the embodiment of the multi-plug connector. Therefore, both power and signal cables can be mounted in the plug. On the plug 7 there is a sleeve 15, which extends around the plug around its entire circumference. The configuration of the opening 9 at the front of the coupling nut 8 is such that it only allows the sleeve 15 of the plug 7 to pass through it. This means that the shape of the hole 9 in front of the connecting nut 8 is identical to the shape of the sleeve 15, although slightly larger. The plug 7 passes so far through the union nut 8 that the sleeve 15 on the plug 7 disappears immediately below the material that forms the front of the union nut 8. Unlike the sleeve 15 of the plug 7, the union nut 8 is formed in the form of a circle, the hole in the union nut 8 forming a circle having a larger radius than the largest radius of the plug body, typically slightly larger than the largest radius of the sleeve 15. When the union nut is turned ninety degrees to lock, the hole 9 at the front, where it creates a small radius, will position itself outside the sleeve 15, where it will create a large radius. This causes the front of the coupling nut 8 to lock onto the sleeve 15 and therefore the plug 7 maintains its position in the socket 6. FIG. 8 shows a plug inserted into a socket having a union nut 8 mounted on it, wherein the union nut locks the connector 7 in its position. Wave-shaped finger holders 16 make it easier to hold the union nut 8. To release the lock again, it is necessary to hold the pin 12 through the hole 17 on the side of the coupling nut 8 with the tool at the same time as the connector 8 is rotated back. It is now possible to remove plugin 7.

[0018] As there is only one way to mount the plug in the socket 6, it is also only possible to insert the plug when the union nut 8 is placed in the inoperative position. This is due to mechanical coding, which is carried out so that the plug 7 is provided with a recess 18, which has an equivalent in the socket. If it is not desired to insert the plug 7 into the socket 6, it can be mounted with a sealing plug, which is consequently blocked by a connecting nut

8.

[0019] Fig. 9 shows a cross section through parts of the housing where the plug 7 is inserted into the socket 6. The union nut 8 locks onto the plug sleeve 15 so that it cannot be pulled off. It is conceivable that the plug may be equipped with another sleeve such that the lower sleeve locks below the front of the coupling nut and the upper sleeve locks above the front of the coupling nut so that it also ensures that the plug cannot move further into the socket when the coupling nut is turned to the locked position. Alternatively, the union nut can be fitted with a double front in which the gap between the two fronts is adapted to grip the plug sleeve. In this arrangement, the electrical connection between the socket and the plug is protected against damage caused by possible jerking of the plugs.

[0020] Fig. 10 shows the housing 19 for the control unit 20 for the actuator system. It can easily be seen that the sockets are equipped with a union nut 8 for locking the plug 7 inserted into the socket 6. Thus, the invention not only relates to blocking plugs 7 in socket 6 in connection with actuators 1 as such, but also to blocking plugs in sockets in housings of all kinds for electrically connected units forming part of the actuator system, e.g. actuator 1, hand control, cleaning indicator, control panel, reading lamp or, as shown, control unit 20.

[0021] Since when configuring the hole in the connecting nut 8, there is a large freedom for its cross-section as long as the plug can pass through it and when it is fully inserted into the socket in the area in the longitudinal direction of the plug located immediately below the front of the connecting nut and up, up to immediately above the front of the connecting nut, it has a cross-section that is smaller than the smallest radius in the hole seen from the midpoint. In addition, more embodiments can be imagined for the configuration of the bore profile as shown in Fig. 11, in which the opening 9 is shaped as a triangle. The dashed line represents the hole profile in the connecting nut when it is turned relative to the plug 7. In the same way fig. 12 shows a square profile. Profile in fig 13 is oval and assumes the greatest similarity to the profile known from the Minifit plugin. In all three profiles, the maximum cross-section that the plug can have at the height of the plug that fits the front of the coupling nut 8 must be the narrowest cross-section of the opening at the front if it would be possible to rotate the coupling nut completely around the plug. The part of the plug that does not fall into the socket and is placed on the front has a lot of flexibility when it comes to configuration and can e.g. be an angled plug. The part of the plug that enters the socket 6 must of course have a cross-section that is so along the entire length of the plug 7 that the plug 7 can both pass through the hole 9 in the coupling nut 8, and can also be inserted correctly to connect the plug in the socket

6. It should be emphasized that these three examples may be supplemented by many other examples of cross sections. All three examples here are symmetrical cross sections, but it should be noted that nothing stands in the way of an asymmetrical cross section. An unbalanced hole may unnecessarily cause mechanical coding 18 of the plug and equivalent 18a in

Socket, as through such an asymmetrical cross section, the plug can only be inserted through the socket in one way. Similarly, the hole 9 at the front of the union nut 8 need not be centered at the front of the union nut, but it may very well be shifted sideways.