BASSI, Alberto (Via Gorizia, 154, Torino, Torino, IT)
| CLAIMS 1. A hinge (1) for a door (2) with automatic return stroke up to a predetermined door opening angle (A2), in particular for electric household appliances, comprising: a first (10) and a second (11) body rotationally and reciprocally coupled about a hinge rotation axis (R) and provided with respective angular restraining means (12,13) to make one of them integral with a rotating element, such as a door (2), and the other integral with a fixed element (4) of an electric household appliance; and elastic means (14) mounted between the first and the second body (10,11) to be elastically loaded by a relative rotation therebetween starting from a first reciprocal angular position thereof; characterized in that it further comprises: - a linking element (15) mounted so as to be radially movable with respect to said hinge rotation axis (R) between a radially outer lateral surface (16) of the first body and radially inner lateral surface (17) of the second body; - means (18) for pushing the linking element (15) against the radially inner lateral surface (17) of the second body ( 11 ) ; - a radial recess (19) obtained in said radially inner lateral surface (17) of the second body and adapted to receive the linking element (15) to make it angularly integral with the second body (11); - cam means (21; 43) operatively associated with the linking element (15) and carried angularly integral by said first body (10), radially protruding from the radially outer lateral surface (16) of the latter by a radial height such so to leave a predetermined radial clearance (g) between them and the radially inner lateral surface (17) of the second body; and - a radial shoulder (22; 45) defined by said cam means on the first body (10) so as to face toward the radial recess (19) of the second body for defining an angular stop designed to restraining the linking element (15) angularly integral to the first body (10); said radial shoulder (22; 45) and said radial recess (19) being arranged angularly spaced from each other by a predetermined angle (βΐ), in said first reciprocal angular position of the first and second body. 2. A hinge according to claim 1, characterized in that said predetermined spacing angle (βΐ) between said radial shoulder and said radial recess, in said first reciprocal angular position of said first and second body (10,11), is substantially egual to said predetermined door opening angle (A2). 3. A hinge according to claim 1 or 2, characterized in that said means (18) for pushing the linking element (15) against the radially inner lateral surface (17) of the second body consist of elastic means (14) . 4. A hinge according to one of the preceding claims, characterized in that said linking element (15) comprises a pin (27) arranged parallel to the hinge rotation axis (R) and a roll (28) provided with an axial hole by means of which the roll is idly engaged on said pin (27); said axial hole of the roll (28) having a slightly larger diameter than the transversal dimensions of the pin (27), measured in the radial direction with respect to the hinge axis. 5. A hinge according to claim 4, characterized in that said pin (27) is integrally carried by a first end (25) of said elastic means (14) . 6. A hinge according to one of the preceding claims, characterized in that said elastic means (14) consist of a helical spring mounted so as to be wound on a bearing hub (23) and having a slightly larger winding diameter than the diameter of said bearing hub; the spring (14) ending with first and second rectilinear opposite ends (25,26); the first end (25) tangentially and overhangingly protruding with respect to a first end winding coil (24b) of the helical spring (14) facing the first body (10) and being L-folded on the side opposite to the second end (26) to form a pin (27) arranged parallel to the hinge axis, between said inner lateral surface (17) of the second body and outer lateral surface (16) of the first body; and the second end (26) radially and overhangingly protruding with respect to a second end winding coil (24c) of the helical spring (14) facing the second body (11) and being adapted to engage said recess (19) to remain in use angularly restrained so as to be integral with the second body (11) ; said first and second ends (25,26) of the helical spring being angularly spaced from each other in a circumferential direction by a predetermined angle . 7. A hinge according to claim 6, characterized in that said predetermined angular spacing angle between said ends (25, 26) of the spring is greater than said predetermined door opening angle (A2). 8. A hinge according to claim 6 or 7, characterized in that at least said second body (11) is cup-shaped and arranged with the concavity facing the first body (10) to define a chamber (30) for the helical spring, the engaging element and the cam means between said first and second body; said first and second body (10,11) being reciprocally coupled to be idle and axially integral to each other by means of said bearing hub (23), which is integrally obtained in one piece with a bottom wall (31) of said second body, from which it centrally and overhangingly protrudes towards the first body, and by means of a pin (32) which centrally and overhangingly protrudes from a flange end (33) of the first body with which it is obtained integrally in one piece and which is idly coupled within an axial through hole of the bearing hub (23) of the first body, preferably with the interposition of a metal washer (34) between an axial shoulder (35) of the pin and a frontal edge of the bearing hub (23); a screw (36) which is coupled with a seat (37) of a free end of the pin (32) thus axially locking the first body (10) against the second body ( 11 ) . 9. A hinge according to one of the preceding claims, characterized in that said cam means consist of a metal washer (43) angularly mounted so as to be integral on the first body (10) and provided with a radial recess (45) arranged, the door being closed, substantially at said linking element (15). 10. A hinge according to one of the preceding claims, characterized in that said radial recess (19) of the radially inner lateral surface (17) of the second body (11) is delimited by respective radial walls (42) obliguely arranged with respect to the hinge rotation axis and diverging from one another towards the same. |
TECHNICAL FIELD
The present invention relates to a hinge for a door of an electric household appliance capable of providing an automatic return stroke for the door only up to a predetermined door opening angle.
BACKGROUND ART
In the field of electric household appliances, in particular of refrigerators, ensuring the possibility of an automatic return of the refrigerator door to the closing position is known to be useful in order to avoid the inattentive user from leaving the door only ajar and not closed in abutment, or even open, with a conseguent major waste of energy consumption.
However, it may be not very practical to provide the door hinge with a return spring, which is elastically loaded during the step of opening the door to then return the door to the closing position once the user has abandoned the door handle, because when users want to open the door wide, e.g. for arranging food in the refrigerator compartment, they would be forced to hold the door open in some way against the bias of the spring.
DISCLOSURE OF INVENTION
It is an object of the present invention to solve the aforesaid problem by providing a door hinge, in particular for a door of an electric household appliance, such as a refrigerator, which is capable of providing an automatic return stroke for the door only up to a predetermined door opening angle, thus leaving the door free from the bias of the spring for each opening angle of the door higher than the predetermined one .
It is a further object of the invention to carry out the aforesaid function by means of a hinge which is simple in structure, cost-effective to be made, little subject to wear and not subject to jamming in use.
The present invention thus relates to a hinge for a door of an electric household appliance with automatic return stroke up to a predetermined door opening angle, as defined in claim 1.
In particular, the hinge according to the invention comprises first and second bodies rotationally and reciprocally coupled about a hinge rotation axis and provided with respective angular restraining means to make one of them integral with a rotating element, such as a door, and the other integral with a fixed element, such as a door jamb or frame of an electric household appliance; and elastic means mounted between the first body and the second body to be elastically loaded by a relative rotation therebetween from a first reciprocal angular position.
According to the invention, the hinge further comprises, in combination: a linking element mounted so as to be radially movable with respect to the hinge rotation axis between a radially outer lateral surface of the first body and a radially inner lateral surface of the second body; means for pushing the linking element against the radially inner lateral surface of the second body; a radial recess obtained at the radially inner lateral surface of the second body and adapted to receive the linking element to make it angularly integral with the second body; cam means operatively associated with the linking element and carried by the first body so as to be angularly integral and radially protruding from the radially outer lateral surface of the latter over a radial height such so to leave a predetermined radial clearance between them and the radially inner lateral surface of the second body; and a radial shoulder defined by the cam means on the first body so as to face the radial recess of the second body for defining an angular stop adapted to angularly restrain the linking element integral with the first body.
The radial shoulder and the radial recess are also arranged angularly spaced from each other by a predetermined angle, in the mentioned first reciprocal angular position of the first and second bodies, corresponding to a door closing position, which angle is substantially equal to the mentioned, predetermined door opening angle, which is established during the step of designing . Thereby, when the door is opened by an angle having a lower value than the predetermined value, the door rotation produces a relative rotation between the first and second bodies which is contrasted by the mentioned elastic means, which are operatively connected to the linking element, which abuts against the radial shoulder and is thus angularly restrained to the first body, while it "walks" on the radially inner side wall of the second body; when released, the door is returned to the closed position by the elastic means.
Continuing instead the relative rotation between the first and second bodies, a gradual approach of the radial recess to the linking element is obtained, until the radial recess faces the linking element, substantially at the reguired, predetermined door opening angle; the latter, as a conseguence of the radial push exerted thereon towards the side wall of the second body — which push is obtained, according to a feature of the invention, by the same mentioned elastic means which are mounted so as to be radially preloaded — engages the radial recess of the second body, being released from the radial shoulder of the first body, while becoming angularly integral with the second body.
Under these conditions, the door rotation may continue (or be interrupted) without the elastic means taking the door back, because the linking element "walks" on the lateral surface of the cam means, which simultaneously prevent the elastic means, which consist of a helical spring having winding axis coinciding with the hinge rotation axis, from recalling the same towards such an axis .
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the present invention will become apparent from the following description of a preferred embodiment thereof, merely provided by way of non-limitative example, with reference to the accompanying drawings, in which:
- figure 1 shows an axonometric, three-guarters top view of an electric household appliance provided with a hinge made according to the invention;
- figure 2 shows some elements of the hinge in figure 1 in the same view as figure 1, but in exploded configuration;
- figure 3 shows the hinge in figure 1 without the elements in figure 2 and sectioned along the hinge rotation axis, so as to leave the interior of the hinge itself in view;
- figures 4 and 5 show sections taken along plotting planes IV-IV and V-V of the hinge of the invention in the configuration in figure 3;
- figures 6, 7 and 8 schematically show the operation of the hinge in figure 1; and
- figures 9 and 10 show a possible variant of the hinge in figure 1 in axial section, elevation and section views according to a plotting plane X-X.
BEST MODE FOR CARRYING OUT THE INVENTION With reference to figures from 1 to 5, numeral 1 indicates as a whole a hinge for a door 2 having, as explained in greater detail below, an automatic return stroke only up to a predetermined door opening angle A2 (figure 8 ) .
Hinge 1 is intended to eguip electric household appliances, in particular a refrigerator 3, and comprises a first body 10 and a second body 11 reciprocally coupled in a rotational manner to rotate about a hinge rotation axis R and provided with respective angular restraining means 12, 13 (consisting of respective eccentric pins with respect to axis R) to make them integral in use, in this illustrated case body 10 integral with a bracket 4 and body 11 integral with door 2. Bracket 4, provided with holes for the pins 12, is a fixed element of the electric household appliance 3, integral with a jamb or frame 5 thereof, also defining a door jamb, against which door 2 rests in contact in the door closing position; whereas door 2 forms the rotating element of the electric household appliance 3 to be eguipped and, in this case, is also eguipped with a bracket 6 adapted to accommodate the bodies 10, 11 therein and provided with holes for accommodating pins 13.
According to one aspect of the invention, elastic means 14 are mounted between the first and second bodies 10 and 11 to be elastically loaded by a relative rotation between the bodies 10, 11 starting from a first reciprocal angular position, shown in figures 4, 5 and 6 and in which (figure 6) door 2 is in a closing position, abutting against the door jamb or frame 5.
In addition to bodies 10,11 and to the elastic means 14, hinge 1 according to the invention comprises a linking element 15 mounted so as to be radially movable with respect to the hinge rotation axis R between a radially outer lateral surface 16 of the first body and a radially inner lateral surface 17 of the second body; means, generally indicated by numeral 18 (figure 4), for pushing the linking element 15 against the radially inner lateral surface 17 of the second body 11; and a radial recess 19 obtained in the radially inner lateral surface 17 of the second body and adapted to receive the linking element 15 to make it in use angularly integral with the second body, which recess 19 is defined by the concave part of a boss 20, which is provided radially outside body 11.
The hinge 1 according to the invention further comprises cam means 21 operatively associated with the linking element 15 and carried angularly integral by the first body 10, radially protruding from the radially outer lateral surface 16 thereof over a radial height of such an extent so as to leave a predetermined radial clearance g (figure 5) between cam means 21 and the radially inner lateral surface 17 of the second body 11; and a radial shoulder 22 defined by the cam means 21 on body 10 so as to face the radial recess 19 for defining, in use, an angular stop adapted to restrain the linking element 15 angularly integral with the first body 10.
According to a non-secondary aspect of the invention, the elastic means 14 consist of a helical spring mounted so as to be wound on a bearing hub 23 belonging, in this illustrated case, to body 11 and having a slightly larger winding diameter than the diameter of the bearing hub 23, so that respective turns 24 of spring 14 may either spread or tighten in the radial direction, as explained below, during the operation of hinge 1, upon the elastic deformation of the spring 14 itself. Again according to the invention, spring 14 ends with a first rectilinear end 25 and with a second rectilinear end 26, opposite to end 25.
With the spring 14 being completely relieved and thus undeformed, end 25 tangentially and overhangingly protrudes (figure 4, dashed part) with respect to a first end winding coil 24b of the helical spring 14 facing the first body 10 and is L-folded on the side opposite to the second end 26 to form a pin 27 arranged, in use, parallel to the hinge axis R and between the surfaces 16 and 17.
The second end 26, instead, radially and overhangingly protrudes with respect to a second end winding coil 24c of the helical spring 14 facing the second body 11 and is adapted to engage, in use, the recess 19 to remain, in use, angularly restrained so as to be integral with the second body 11. In particular, according to one aspect of the invention, the ends 25 and 26 of the helical spring 14 are angularly spaced from each other in a circumferential direction by a predetermined angle, which is preferably slightly larger than the mentioned door opening angle A2 from which the failure to return of door 2 to the closing position is required.
Thereby, the elastic means consisting of the helical spring 14 form, with the tangentially protruding end 25, the mentioned means 18 for pushing the linking element 15 against the inner lateral surface 17 of body 11, while pin 27 is integrally carried by the end 25 of the elastic means 14, being defined by the L-folded portion of end 25.
The linking element 15 thus comprises pin 27 and, preferably, a roll 28 provided with an axial hole by means of which roll 28 is idly engaged on pin 27.
The axial hole of roll 28 preferably has a slightly larger diameter than the transversal dimensions of pin 27, measured in the radial direction with respect to the hinge axis R, so that roll 28 is adapted to roll, in use (as explained below), on the surface 17; the cam means 21 are delimited by a lateral surface 29, facing and parallel to the inner lateral surface 17 of the second body 11, spaced therefrom by the clearance g, which is equal to a greater amount than the diameter of pin 27.
According to the invention, when the bodies 10 and 11 are in the mentioned first reciprocal angular position, in which door 2 is in the closed position (figures 4 and 6), the radial shoulder 22 and the radial recess 19 are also reciprocally arranged angularly spaced by a predetermined angle, which is substantially egual to the reguired, predetermined door opening angle A2, beyond which the failure of door 2 to automatically return to the closing position is reguired.
This is obtained by means of a convenient shape of the bodies 10 and 11. In particular, at least body 11 is cup-shaped and arranged with the concavity facing body
10 to define, between the bodies 10 and 11, a chamber 30 (figure 3) for the helical spring 14, the engaging element 15 and the cam means 21.
Furthermore, the bodies 10, 11 are reciprocally coupled to be idle and axially integral to each other by means of the bearing hub 23, which is integrally obtained in one piece with a bottom wall 31 (figure 3) of the second body 11, from which it centrally and overhangingly protrudes towards body 10, and by means of a pin 32, which centrally and overhangingly protrudes from a flanged end 33 of the first body 10 with which it is integrally obtained in one piece.
Pin 32 is idly coupled within an axial through hole of the hub 23, which is tubular, preferably with the interposition of a metal washer 34 between an axial shoulder 35 of pin 32 and a frontal edge of the bearing hub 23, and is held in position, with the bodies 10 and
11 being coupled, by a screw 36 which is coupled with a seat 37 of a free end of the pin 32 thus axially locking the first body 10 against the second body 11.
For the reguired angular positioning of recess 19 and the radial shoulder 22, ribs 38 are thus provided inside body 11, i.e. on surface 17 (which are also used to contain, on the outside, the spring 14), of which rib 38b is higher, so as to remain, with the bodies 10, 11 being coupled, facing the lateral surface 16 of body 10, in this case defined by the side wall of pin 32 (figure 3) to intercept, in use, a radial tab 39 of body 10, integrally obtained with the flanged end 33.
Hinge 1 finally comprises a pin 40 (figure 2) concentrically mounted in a blank cylindrical seat 41 of the first body 10, obtained through the flanged end 33 thereof and on the opposite side of the seat 37 for screw 36. Furthermore, according to a preferred aspect of the invention, the radial recess 19 of the radially inner lateral surface 17 of the second body 11 is delimited by respective radial walls 42 obliguely arranged with respect to the hinge rotation axis R and diverging from one another towards the same.
For assembling hinge 1, spring 14 which is in its undeformed configuration shown by a dashed line in figure 4, is introduced into body 11, being careful to obtain the engagement of recess 19 with the end 26; thereby, end 26 is restrained so as to be angularly integral with body 11, whereas end 25 is radially bent towards axis R to introduce it into body 11, in contact with surface 17.
The subsequent assembly of roll 28 on pin 27, in contact with surface 17, increases the bending of the end 25.
Body 10 is then assembled by engaging the part of pin 27 which is closest to coil 24b with shoulder 22 and engaging tab 39 with rib 38b. Finally, the bodies 10 and 11 are reciprocally secured by means of the screw 36.
In use (figures 6-8), with door 2 being closed, the bodies 10, 11 are in the reciprocal assembly position shown in figures 5 and 6. When door 2 is opened, up to an opening angle Al (figure 7), body 11 rotates with door 2 about axis R, whereas body 10 (which is restrained to bracket 4) is still; therefore, recess 19 approaches the radial shoulder 22, thus reducing an angle β (of circumferential extension with respect to axis R) comprised between the two by an angle βΐ (figure 6) and an angle β2 (figure 7); therefore, pin 27 is abuttingly pushed even more against the shoulder 22 (which does not move) and coils 24 of spring 14 are deformed: spring 14 then reacts by applying to body 11 an elastic reaction torque which, when the user lets the door 2 go, returns it to the initial closing position. At the same time, roll 28 "walks" on the radially inner lateral wall 17 of body 11.
Once a door opening angle equal to A2 is reached (figure 8), however, recess 19 is substantially nearly facing the element 15 consisting of pin 27 and the respective roll 28; the latter, under the bias of the elastic reaction of spring 14 and, in particular, of its end 25, thus engage the recess 19, making at this point the element 15 and, thus, the end 25 of spring 14, angularly integral with body 11, as the end 26 already is. This produces a radial outward movement of the element 15 in the direction of the arrow (figure 8) which disengages pin 27 from shoulder 22 and takes the same to be tangent to the inner lateral surface 17 of body 11 with which it is now integral because the roll 28 (part shown with a dashed line in figure 8) engages the recess 19.
Continuing then the opening rotation of door 2 beyond angle A2, spring 14 applies a direct elastic reaction radially on element 15, by pushing it against the body 11 with which it is now integral and thus completely neutralized. Therefore, door 2 is not recalled towards the closing position and may be left open by the user, in any position beyond the angle A2 and up to the maximum angular opening position (not shown) .
During the step of closing the door, on the other hand, when door 2 reaches angle A2 again, the elastic reaction of spring 14, combined with the relative motion between the bodies 10 and 11, pushes roll 28 to cooperate against the obligue walls 42 of recess 19, which guide the same towards axis R and finally take pin 27 back to engage shoulder 22; thus, at this point, door 2 is again subject to the elastic reaction torgue exerted by spring 14 and may proceed with the closing stroke alone.
Finally, with reference to figures 9 and 10, in which similar or egual details to those already described are indicated with the same numbers for simplicity, numeral 100 indicates a hinge element adapted to replace the module formed by the bodies 10,11 in figure 2. In practice, module 100 consists of two bodies 10,11, completely similar to those already described, coupled with the interposition of a helical spring 14 and of the radially movable linking element 15. The only difference consists in that the cam means 21, integrally obtained in one piece with body 10, are replaced by cam means consisting of a metal washer 43 of a given thickness, provided with a cylindrical lateral surface 29 and angularly mounted on body 10 so as to be integral therewith by means of radial grooves 44, provided with a radially external, radial recess 45 which interrupts the surface 29 and which is shaped so as to have almost the same size as the linking element 15, i.e. pin 27 with roll 28, and with the door being closed, is substantially arranged at the linking element 15. Such a recess 45 replaces shoulder 22 with egual efficiency, by defining a double radial shoulder with its circumferential ends.
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