Safety castor wheel for furniture articles

Abstract: The present invention relates to a safety castor wheel, which has been specifically designed for furniture articles and the like. The castor wheel comprises a supporting element which can be associated with the furniture article and which supports rotatably, about a substantially horizontal axis, at least a wheel. The safety castor wheel comprises moreover a lever locking element (7) which is pivoted, at a middle portion thereof, to the supporting element (2), about a parallel axis (8) spaced from the wheel axis (4). The locking element (7) has one end thereof provided with a tooth arrangement (9) which can be engaged with or disengaged from, by causing the locking element to swing about the pivot pin thereof, a gear ring (10) rigid with the wheel. The other end portion of the locking element outwardly projects from the castor wheel-supporting element assembly and can be driven to cause the locking element (7) to swing about the pivot pin or fulcrum thereof.

Description: BACKGROUND OF THE INVENTION The present invention relates to a safety castor wheel which has been specifically designed for furniture articles and the like, and, in particular, for bed articles. Safety castor wheels for furniture pieces or articles are already known, which generally comprise a supporting element which can be associated with the furniture article and which rotatably supports, about a substantially horizontal axis, at least a castor wheel. Safety castor wheels are moreover known including a locking device which can be actuated or deactuated in order allow or prevent the castor wheel from turning, depending on requirements. A safety castor wheel according to the preamble of claim 1 is known from EP-A-0650854. Some types of at present commercially available safety castor wheels have the drawback that they do not provide a proper safety against an accidental deactuating of the locking device, after the actuating thereof. Yet other safety castor wheels are comparatively complex construction wise, which negatively affects their making costs. SUMMARY OF THE INVENTION Accordingly, the aim of the present invention is to overcome the above mentioned problem, by providing a safety castor wheel, which, while having a very simple construction, provides a good safety against a possible accidental disengaging of the castor wheel locking device. Within the scope of the above mentioned aim, a main object of the present invention is to provide such a safety castor wheel which can be made at a competitive cost. Yet another object of the present invention is to provide such a safety castor wheel, which can be easily assembled on a broad range of furniture articles or pieces such as beds, tables, small tables as well as patient transporting beds, emergency small beds and the like. A further object of the present invention is to provide such a safety castor wheel which has such a mechanical strength as to be very reliable in operation and have a long duration. According to one aspect of the present invention, the above mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by a safety castor wheel, for furniture articles and the like, according to claim 1. Further embodiments of castor wheels according to the invention are disclosed in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS Further characteristics and advantages of the safety castor wheel according to the present invention will become more apparent hereinafter from the following detailed disclosure of a preferred, though not exclusive, embodiment of said safety castor wheel which is illustrated, by way of an indicative, but not limitative, example, in the accompanying drawings, where: Figure 1 is an elevation partially cross-sectioned view illustrating the safety castor wheel according to the present invention, with the locking element thereof in a castor wheel engaging condition; Figure 2 illustrates, by a similar view to figure 1, the subject castor wheel with the locking element thereof being disengaged from the castor wheel; Figure 3 is an exploded perspective view illustrating some of the component elements of the safety castor wheel according to the present invention; Figure 4 is a front elevation view of the safety castor wheel according to the present invention; and Figure 5 is a partially cross-sectioned front elevation view illustrating the safety castor wheel according to the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to the number references of the above mentioned drawing figures, the safety castor wheel according to the present invention, which has been generally indicated by the reference number 1, comprises a supporting element 2, which can be associated with the furniture article or piece to be equipped by the safety castor wheel, by using, for example, a suitably designed cylindric seat 3 formed in the supporting element 2 and adapted to be engaged with a pin element coupled, in a per se known manner, to the furniture article. In particular, the connection of said pin element with the seat 3 can be of a rotary type, so as to allow the castor wheel 1 to turn and spin about the pivot pin thereof. The supporting element 2, as shown, supports, in a rotary manner about a substantially horizontal rotary axis 4, at least a wheel element 5. More specifically, the wheel element 5 comprises preferably a pair of wheels proper 5a and 5b, coaxial to one another, and of like diameter, said wheels 5a and 5b being rotatably supported about the rotary axis 4 of the supporting element 2, by a pivot pin 6. The safety castor wheel according to the present invention comprises moreover a lever locking element 7 which is pivoted, at a middle portion thereof, to the supporting element 2, about an axis 8 parallel to and spaced from the rotary axis 4. The locking element 7, in particular, is provided with an end portion thereof including a tooth arrangement 9 which can be engaged with or disengaged from, by causing the locking element 7 to swing about the axis or fulcrum 8 thereof, a gear ring 10, rigid with the wheel element 5. The other end portion 11 of the locking element 7 has a pedal arrangement and projects from the assembly constituted by the wheel element 5 and supporting element 2, so as to be adapted for operation by an user, for example in a very simple manner, by a foot of the user, in order to cause the locking element 7 to swing about the fulcrum or rotary axis 8, in a direction or in the other, thereby causing the tooth arrangement 9 to engage with or disengage from the gear ring 10. In the safety castor wheel according to the present invention, the two wheels 5a and 5b are provided with a gear ring 10, and the locking element 7 is provided with two twin tooth arrangements 9, as shown in a very clear manner in figure 3, which are provided to respectively engage with the tooth arrangement 10 of the wheel 5a and the tooth arrangement 10 of the wheel 5b. Moreover, the locking element 7 is supported by the supporting element 2, at a region included between the two wheels 5a and 5b. The safety castor wheel according to the present invention comprises moreover restraining means for restraining the locking element 7 at the engagement and disengagement positions thereof with respect to the gear ring 10. These restraining means, in particular, comprise a ridge 12 formed on the supporting element 2 and which can be selectively connected to one of the two recesses 13 and 14 formed in the locking element 7 at two angularly spaced regions thereof, about the rotary axis or fulcrum 8. Preferably, it will be possible to provide two twin ridges 12 or, as shown, two recesses 13 and two recesses 14 on the locking element 7, in an analogous manner to that disclosed with respect to the tooth arrangement 9, in view of the provision of two wheels 5a and 5b. More specifically the ridges or projections 12 and the recesses 13 and 14 have preferably curved shapes, mating with one another, so as to provide a proper coupling or engaging of the ridges 12 and recesses 13 and 14, thereby providing very good safety properties against a possible accidental swinging of the locking element 7 about the fulcrum or rotary axis 8 thereof. In this connection it should be pointed out that the two wheels 5a and 5b, the supporting element 2 and the locking element 7 are preferably made of a molded synthetic or plastic material, thereby they can be constructed at a very reduced cost. The operating of the safety castor wheel according to the present invention is as follows. As it is required to turn the wheels 5a and 5b so as to allow the furniture article including the safety castor wheel to be easily displaced, then the locking element 7 will be arranged at the position thereof shown in figure 2, i.e. in which its tooth arrangement 9 is disengaged by the gear ring 10. With the locking element in this condition, the wheels 5a and 5b can turn, in an idle manner, about the rotary axis 4. The locking element 7, in particular, can be held in this position by coupling the recess 13 and ridge 12. As the wheels 5a and 5b must be locked, then the end portion 11 of the locking element 7 will be actuated so as to cause the locking element to swing about the fulcrum 8, thereby causing the tooth arrangement 9 to engage with the gear ring 10 of the wheels 5a and 5b. The locking element 7, in particular, can be held in the engagement condition thereof, in which it engages with the gear ring 10, by coupling the recess 14 and the ridge 12. In this connection it should be moreover pointed out that the locking element 7 is moreover provided with a slot 20 operating for providing resiliency properties to that end portion of the locking element 7 in which are formed the two recesses 13 and 14 therein are engaged the two ridges 12. This resiliency will allow a limited displacement of the bed or furniture article as it is subjected to an accidental impact by an user, so as to automatically return to a braking position thereof. Such a result will be assured by the resiliency of the mentioned portion of the locking element 7, provided to said element by the provision of the slot 20. From the above disclosure and from the several figures of the accompanying drawings it should be apparent that the invention fully achieves the intended aim and objects. In particular, the fact is to be pointed out that a safety castor wheel has been provided which has a very simple construction, while providing very good properties against an accidental locking and unlocking thereof. While the safety castor wheel according to the present invention has been hereinabove disclosed with reference to preferred embodiments thereof, it should be apparent that the disclosed embodiments are susceptible to several modifications and variations all of which will come within the scope of the appended claims.

Claims: A safety castor wheel (1), for furniture articles and the like, comprising a supporting element (2) which can be associated with said furniture article and which rotatably supports, about a substantially horizontal axis, at least a wheel element (5), a locking element (7) pivoted about a parallel axis to the axis (4) of the wheel element, said locking element (7) including an end portion provided with a tooth arrangement (9) which can be engaged with or disengaged from, by causing said locking element (7) to swing about the pivot pin thereof, a gear ring (10) rigid with said wheel element (5), the other end portion (11) of said locking element (7) outwardly projecting of the wheel element (5)-supporting element (2) assembly, restraining means for restraining said locking element (7) of the engagement and disengagement positions thereof with respect to said gear ring (10), characterized in that said locking element (7) pivots at a middle portion thereof to said supporting element (2) about a pivot pin (8) parallel to and spaced from said rotary axis (4), and that said locking element (7) comprises a slot (20) operating to make resilient an end portion of said locking element (7) in which are defined two angularly spaced recess means (13, 14) in which can be selectively engaged ridge means (12) formed on said supporting element (2), said recess and ridge means pertaining to said restraining means. A safety castor wheel, according to Claim 1, characterized in that said two recess means (13, 14) comprise two first recesses (13) and two second recesses (14) on said locking element (7) and said ridge means comprise two twin ridges (12). A safety castor wheel, according to Claim 1, characterized in that the axis of said gear ring coincides with the axis of said wheel element (5). A safety castor wheel, according to Claim 1, characterized in that said wheel element (5) comprises a pair of coaxial wheels (5a, 5b), of like diameter, each said wheels including a gear ring (5) which can be engaged by said locking element (7). A safety castor wheel, according to Claim 1, characterized in that the other end portion (11) of said locking element has a pedal shape. A safety castor wheel, according to Claim 4, characterized in that said locking element (7) is supported by said supporting element between said pair of wheels (5a, 5b). A safety castor wheel, according to Claim 1, characterized in that said supporting element (2) is provided with a vertical axis seat (3) for receiving a connection pin for connection with said furniture article. A safety castor wheel, according to any of the preceding claims, characterized in that said supporting element (2), locking element (7) and said wheels (5) are made of a plastic material.

Inventors: TREVINI RUGGERO, TREVINI, RUGGERO
Applicants: O G T M OHG S R L, O.G.T.M. OFFICINE MECCANICHE S.R.L.
Application year: 1997
Main classification: B60B33
IPC codes: B60B33