The invention relates in first instance to a mounting plate which is placeable on a fork or a rotary bearing of a caster and which is connectable to the fork or a part of the rotary bearing.
The invention further relates to a caster comprising a fork and/or a rotary bearing, and also a wheel, and a mounting plate disposed at the upper side of the fork or the rotary bearing.
Moreover, the invention relates to a caster comprising a wheel and a fork, the fork being rotatable about a vertical axis of rotation relative to a locking part, and a first spring part, fixed to the fork, being provided for interacting with the locking part with regard to rotational locking.
Casters of the mentioned kind are already known in many respects. In first instance, reference is made to DE 20 2006 014 765 U1. The transmission part provided in this caster is held within the fork and on the rotary bearing, and is biased into the locking or blocking position by means of a (single) spring that is formed as a compression spring.
The known caster also has a mounting plate which, however, is formed as an integral part of the rotary bearing.
A caster is known from DE 22 39 339 A1, the transmission part of which is to be actuated via a sliding part that is disposed above an upper end of the transmission part so as to be displaceable transversely with respect to the movement of the transmission part. The caster is formed in a conventional manner with a receiving journal in which the transmission part, which is secured to the caster, is accommodated. A comparable configuration of a caster is also disclosed in U.S. Pat. No. 5,579,871 A.
Based on the mentioned prior art, it is an object of the invention to provide a configuration of a mounting plate that is advantageous with regard to a lockable caster, and/or to provide an advantageous caster having a locking device and a mounting plate, and/or to provide an advantageous embodiment of a caster having a locking device.
One possible approach to achieving said object is provided according to a first inventive concept by a mounting plate that has a transmission part which is provided on the underside on the mounting plate and is connected thereto for locking the caster, optionally a wheel of the caster, the transmission part to be acted on by a sliding part which likewise is connected to the mounting plate. According to the invention, the mounting plate, which is provided separately from, but which is connectable to, the rotary bearing or the fork, is provided with a functional part that is suitable for acting on the rotary bearing and/or a wheel of the caster. Due to the fact that the transmission part is connected to the mounting plate, as well as the device for acting on the transmission part, namely in the form of the sliding part, the mounting plate can be placed as a prefabricated unit on a caster substructure, which comprises only the fork with a wheel mounted therein and optionally a rotary bearing, and in which furthermore an acting part for locking the wheel and/or for rotational blocking of the caster can also optionally be provided. In the same manner, the bottom part of the caster can be removed from an existing assembly comprising such a mounting plate and the bottom part of the caster, and can be replaced by another one, for example.
The sliding part makes it possible to form the mounting plate without a part protruding beyond the mounting surface formed on the upper side in this manner. The sliding part is preferably disposed so as to be movable parallel to a plane of the upper side of the mounting plate, more preferably, on an underside of the mounting plate.
Another possible approach to achieving the object is provided by a caster in which the transmission part is provided on the underside of the mounting plate and is held thereon, for total locking and/or directional locking by acting on the wheel and/or the rotary bearing, the transmission part to be acted on by a sliding part which likewise is held on the mounting plate. For the caster having such a design, no mounting formations are required for the transmission part on the rotary bearing and/or the fork. It is only necessary to provide a through opening in which the transmission part, which extends from the mounting plate and is held thereon, engages. Due to the fact that the transmission part is actuated by a sliding part which, moreover, is likewise held on the mounting plate, the mentioned caster substructure also does not have to be provided with this functional part.
Another possible approach to achieving the object is provided by a caster in which the first spring part is acted on by a second spring part, likewise fixed to the fork, so as to be moved into a release position. The first spring part, which interacts with the locking part for directional locking, can be provided only for a spring-effected engaging biasing with regard to the locking part in the case of activation. Reliable movement and retention in the release position is reserved for another functional part, namely, another spring part.
Further features of the invention are described and illustrated below, also in the description of the figures and in the drawings, often in their preferred association with the features already explained above. However, they may also be of importance in an association with only one or more individual features, which are described herein or illustrated in the drawings, or independently, or in some other overall concept.
Thus, it is preferred that the transmission part is provided for acting on the caster with regard to a directional lock and/or total lock. The transmission part can act in this regard on one or more engagement parts, which preferably are fitted on the caster substructure.
Furthermore, it is preferred that the transmission part can be associated with a central opening of the rotary bearing or is associated with such an opening in the assembled state of the caster or, in this respect, with the integral embodiment of the caster. The rotary bearing, which customarily and preferably is formed from sheet metal parts which are shaped for accommodating balls for forming a ball bearing and of which an upper part also may be formed at the same time as a bearing plate which, more preferably, serves for connecting to the mounting plate, is preferably formed with an inner central opening in which the transmission part can engage or through which it can pass.
The sliding part, as viewed in the vertical direction, is preferably disposed between the mounting plate and the transmission plate. At the same time, the sliding part can thus be guided by a holding part which holds the transmission part and which is likewise secured to the mounting plate, or solely by the holding part.
An actuating lever can be provided for actuating the sliding part. The actuating lever can be acted on by a foot of a user. It is in particular preferred that the actuating lever is likewise mounted on the mounting plate. In this configuration, the mounting plate at the same time also comprises the functional part for actuating the transmission part.
Furthermore, it is preferred that with regard to the mentioned functional parts, which optionally are provided individually or in combination, the mounting plate is provided without springs. In first instance this results in a simple mounting possibility for the mounting plate itself. Moreover, the one or more spring parts, which more preferably are nevertheless provided, are formed in the caster substructure which is to be connected or is connected to the mounting plate, and, for example, can be replaced together with the caster substructure.
With regard to the two spring parts that are provided for interacting with the locking part, it is also preferred that these spring parts are secured to the caster, preferably directly on the fork, so that they are oriented in opposite directions relative to one another. The arrangement in an oppositely oriented manner, an at least partial overlap preferably also being provided, allows an advantageous extent of the respective spring parts. The overlapping or interlocking arrangement also allows an advantageous utilization of space.
It is also preferred that the second spring part has guide extensions between which an engagement portion of the first spring part extends. The engagement portion, which interacts with the locking part, which, for example, can be a metal part comprising a ring gear formation, can be deflected in the rotational direction when under significant (torsional) load and also in dependence on the free spring length of this first spring part. The guide extensions can, for example, provide advantageous stabilization in this respect. It is also preferred that a brake part for locking the wheel is formed at the end of the first spring part that is located opposite from the engagement portion. This brake part can be a conventional brake block. More preferably, this region of the first spring part is disposed in alignment with the central opening and/or the transmission part. Direct action can thus take place.
Furthermore, it is also preferred that the first spring part is formed as a spring lever, more preferably as a spring rocker, and is pivotably mounted on the fork. The first spring part is preferably pivotably mounted in a region located centrally with respect to the longitudinal extent of the first spring part. The brake part is then preferably disposed at one end of the spring lever, and the region interacting with the locking part is formed at the other end of the first spring part.
The invention is explained in greater detail below with reference to the accompanying drawing, which, however, shows only one exemplary embodiment of the invention. In the drawings:
Illustrated and described, in first instance with reference to
The wheel 2 is mounted in the fork 3 by means of an axle 5 (see
A transmission part 7, which can be acted on by a sliding part 8, is secured to the mounting plate 4 (see also
In a further detail, as is also apparent from
Instead of one, or a plurality, or all of the tube segments 14, connection parts can also be provided which have no passage opening and which thus contribute to a closed top surface of the mounting plate 4.
As is apparent in further detail from
While the mounting plate 4 itself is formed, e.g., as a metal part, but preferably is formed as a plastics part, the tube segments or optionally another connection part is/are more preferably formed as metallic parts.
The transmission part 7 is accommodated in a holding part 17 that is secured to the underside of the mounting plate. As can be seen in the exemplary embodiment, the holding part preferably has a dome-like shape. The transmission part 7 as such consists of a tappet part 18 which is freely vertically displaceable, but preferably is limited by a stop, or in any case in a captive form, and which in the exemplary embodiment, in a further detail, accommodates a threaded bolt 19 at the underside which is secured by a nut 20 so as to achieve a counter effect here. The lower head of the threaded bolt is at the same time used for acting on the first spring part 21, which in the exemplary embodiment is provided for both brake locking and directional locking.
The transmission part 7, in the exemplary embodiment the tappet part 18, and preferably, as in the exemplary embodiment, the holding part 17, pass through a central opening 42 of the rotary bearing 43.
The tappet part 18 has an upper enlargement 41 via which it is held captive in the holding part 17, which is narrowed at the lower side with respect to the receiving space.
In a further detail, the sliding part 8, which is vertically situated on the underside of the mounting plate 4 between the mounting plate 4 and the tappet part 18, acts by means of a cam 22 on the end of the transmission part 7 on the mounting plate side, or, in the exemplary embodiment, specifically on the end of the tappet part 18. For this purpose, the tappet part 18 has an activating chamfer 23 on one side.
In the exemplary embodiment and preferably, the cam 22 is formed from the sliding part 8 itself, for example by deformation. The wall thickness of the sliding part 8 can be essentially unchanged, even in the region of the cam 22.
Furthermore, an engagement opening 24 is formed on the sliding part 8, preferably in the end region located opposite the cam 22, for the interaction between the actuating lever 9 and the sliding part 8. In the actuating position (see
The mounting plate 4, as illustrated in detail also in
All parts of the caster 1 according to
In the engagement position according to
In particular, the caster 1 is formed with a directional lock and a total lock. For this purpose, an engagement part in the form of the first spring part 21 is provided. The first spring part 21, which is furthermore apparent and preferably formed in the exemplary embodiment as a lever part or rocker part, has at the one end a brake block, here in the form of a brake block 30 elongated in the direction of the axle 5, that is provided for acting on the wheel surface 29, and has a detent recess 31 at the other end. In the exemplary embodiment, the brake block 30 is accommodated in a portion of the first spring part 21 which is referred to as the brake part 46. By means of the detent recess 31, the first spring part 21 can interact with a tooth formation 32 on the locking part 33 (also see
In the exemplary embodiment, the first spring 21 is vertically pivotable in its end regions about the horizontal axle 35, but is connected in a rotationally fixed manner to the fork 3. Thus, in the total locking position according to
A second spring part 36 is provided which is associated with the first spring part 21. The second spring part 36 is likewise fixedly mounted on the fork; in the exemplary embodiment, it is preferably mounted on the central bearing plate 34. The fastening location, preferably when fastening by means of pushfit rivets 37 (see
It is apparent that the engagement portion 44 of the first spring part 21, which engagement portion forms the detent recess 31, is disposed between the guide formations 39 in an overlapping manner with respect to a vertical projection. With regard to the vertical movement of the engagement portion 44 between the engagement position and the release position, the engagement portion has an upwardly bent hook portion 45 at its free end associated with the second spring part 36. Thus, regardless of the vertical movement, this end region of the first spring part 21 is in each case accommodated between the guide formations 39.
In contrast, the spring arms 38 are disposed in the transverse direction relative to the direction of extent of the first spring part 21 (the direction of extent being viewed in the direction linking the detent recess 31 to the brake part 30), and are disposed spaced apart from the latter. The spring arms 38 act on the first spring part near a mounting pin 40 for the first spring part 21. The first spring part 21, which in this respect is configured in a lever-like manner, is pivotable about this mounting pin 40. The spring arms 38 preferably act on the first spring part 21, as illustrated, at a distance of 1/10 up to 1× the diameter of the actual mounting pin 40 from a geometric pivot axis that passes through the mounting pin.
The mounting pin 40 is directly mounted in the legs of the fork 3.
All features disclosed are (in themselves) pertinent to the invention. The disclosure content of the associated/accompanying priority documents (copy of the prior application) is also hereby included in full in the disclosure of the application, including for the purpose of incorporating features of these documents in claims of the present application. The subsidiary claims in their optional subordinated formulation characterize independent inventive refinement of the prior art, in particular to undertake divisional applications based on these claims.
Number | Date | Country | Kind |
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20 2011 052 981.0 | Aug 2011 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2012/065888 | 8/14/2012 | WO | 00 | 2/19/2014 |