GB2281939A

GB2281939A - Spring hinge with adjustable spring force

Info

Publication number: GB2281939A
Application number: GB9418338A
Authority: GB
Inventors: Ki Seoung Lee
Original assignee: Gold Star Co Ltd
Current assignee: LG Electronics Inc
Priority date: 1993-09-17
Filing date: 1994-09-12
Publication date: 1995-03-22
Also published as: GB9418338D0; CN1103571A; JPH07163457A; CN1044558C

Abstract

An adjustable spring hinge for the lid 14 of an electric cooking vessel comprises a hinge pin 15 for pivotally coupling the lid 14 to the base of the vessel and a plurality of springs 16 mounted on the hinge pin for supplying an opening torque for the lid 14. The springs 16 are coil springs having one arm 16a contacting the lid 14 and a second arm 16b contacting the base. The adjustment device comprises a screw 35 mounted to a support 32 on the base. The screw 35 engages with a lever plate 33 which in turn engages with the am 16b of the spring 16. The screw 35 is moved in or out to tighten or loosen the spring 16 thus adjusting the spring force. <IMAGE>

Description

DEVICE FOR ADJUSTING HINGE SPRING FORCE OF ELECTRIC JAR HAVING PUSH-BUTTON LID BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an electric jar with a push-button lid openable by once pressing a push button and, more particularly, a device for adjusting hinge spring force of the push-button lid of the electric jar for restoring the spring force of the hinge spring of the lid after repeated opening and closing motions of the lid to a predetermined spring force level, thus to keep desired smooth opening and closing motions of the push-button lid for a long time.

Description of the Prior Art The typical electric jars are equipped with either handoperated lids or push-button lids. An electric jar with the hand-operated lid or with the manually openable lid is a socalled handle type electric jar while an electric jars with the push-button lid automatically openable by once pressing the push button is a so-called push-button type electric jar.

Fig. 1 shows in a rear perspective view a push-button type electric jar (hereinbelow, referred to simply as "electric jar") with a typical push-button lid. As shown in this drawing, the electric jar designated by the numeral 11 includes an upper casing 13 that is provided on the top of a right-hexadral main body 12. The top of the upper casing 13 is covered with a push-button lid 14 pivotally coupled to the upper casing 13 by a spring-biased hinge structure. In order to couple the lid 14 to the upper casing 13 while allowing the lid 14 to be opened at a predetermined angle with respect to the upper casing 13, the rear center of the lid 14 is pivotally coupled to the upper casing 13 by inserting a hinge shaft 15 into both a hinge shaft hole (not shown) of the lid 14 and a hinge shaft hole (not shown) of the upper casing 13.

A pair of hinge springs 16 are fitted over the hinge shaft 15 so that the springs 16 are spaced out at an interval so as to keep desired balance of the lid 14 with respect to the upper casing 13 during a lid opening motion. In the front part of the electric jar 11, the top center of the upper casing 13 is provided with a lid opening push button (not shown).

Turning to Fig. 2 showing the spring-biased hinge structure of the electric jar 11 with the lid 14 fully opened in a sectional view taken along the section line A-A of Fig 1, a top arm 16a of each spring 16 is elastically caught by an arm stopper 18 of the lid 14, thus to elastically keep an opened state of the lid 14 with respect to the upper casing 13. Here, the arm stopper 18 is provided in the interior of the lid 14 so that the stopper 14 is perpendicular to the inner surface of the lid 14 or to the vertical surface in Fig.

2. An arm stopper guider 17 vertically placed on the top surface of the main body 12 in the inside of the hinge shaft 15 as shown in Fig. 1. The arm stopper guider 17 having an inclined guide section at its top is adapted for guiding the arm stopper 18 of the lid 14 whenever the lid 14 is opened or closed with respect to the upper casing 13. Formed in the inside of the arm stopper guider 17 is a recess 19 for receiving the arm stopper 18 therein when the lid 14 is closed along with the arm stopper 18 guided by the guider 17.

A spring support block 20 is vertically formed on the top surface of the main body 12 in the outside of the arm stopper guider 17 and under the hinge shaft 15. The support block 20 is provided on the outer surface of the arm stopper guider 17 at two portions of the guider 17, which two portions are horizontally spaced out at an interval. Lower arms 16b of the hinge springs 16 are received in the support block 20 so that the lower arms 16b are horizontally spaced apart from each other by a distance. Mounted on an inner surface of the support arm 20 is an arm stopping shoulder 21 adapted for stopping the lower arms 16b of the hinge springs 16 received in the support block 20.

The electric jar 11 also includes a hook type cover (not shown) that is detachably mounted on the upper casing 13 in the outside of the support block 20.

When pressing the lid opening push button of the electric jar 11, the lid 14 is elastically turned about the hinge shaft 15 owing to the spring force of the hinge springs 16, thus to be opened. At this time, the arm stopper 18 is guided from the recess 19 to a predetermined point or to the top surface of the arm stopper guider 17, at which point the sussed spring force of the hinge springs 16 will be balanced with the weight of the opened lid 14 and which summed spring force will be weakened in accordance with the opening motion of the lid 14.

When the arm stopper 18 has reached the predetermined point, the lid 14 keeps its opened state with respect to the main body 12 at predetermined angles ranged from about 90' to about 100'.

When closing the lid 14, the opened lid 14 is pressed down by force so as to be turned about the hinge shaft 15 in a direction closing the lid 14. When the user presses down the opened lid 14, the balance between the summer spring force of the hinge springs 16 and the weight of the lid 14 is not kept any more so that the opened lid 14 is closed.

However, repeated opening and closing motions of the lid 14 inevitably causes weakening of the intrinsic spring force of each hinge spring 16, thus to cause the point where the summed spring force of the hinge springs 16 will be balanced with the weight of the lid 14 to be lower than the intended point or the top surface of the arm stopper guider 17. With the weakened spring force of each hinge spring 16. due to the repeated opening and closing motions of the lid 14, the lid 14 can not be fully opened and often shakes just when the lisd starts its opening motion.Since the lid 14 can not be fully opened due to the weakened spring force, the push-button lid 14 should be manually opened so as to be fully opened whenever either the content in the kettle (not shown) of the jar needs taking out of the kettle or the kettle needs removing from or installing in the main body 12 before or after boiling of rice. This troubles the users. Furthermore, the lid opening or closing motion may be attended with considerable noise due to shaking of the lid 14 caused by weakened spring force.

In addition, the spring force of each hinge spring 16 exceeding a predetermined level causes another problem. That is, the excessive hinge spring force will exceed the weight of the lid 14 lather than balanced with the lid weight even when the arm stopper 18 has been guided, by the hinge spring force, from the recess 19 to the top surface of the arm stopper guider 17 during a lid opening motion, thus to cause considerable vibration of the lid 14. With such excessive spring force, the hinge springs 16 will lose their intended spring force within a short time.

SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a device for adjusting hinge spring force of a pushbutton lid of an electric jar in which the above problems can be overcome and which adjusts the spring force of the hinge spring of the lid to a predetermined spring force level, thus to keep desired smooth opening and closing motions of the push-button lid for a long time and to reduce the noise generated in the lid opening motion.

In order to accomplish the above object, a device for adjustment of hinge spring force of a push-button lid of an electric jar in accordance with an embodiment of the present invention comprises: an upper casing provided on the top of a main body of the electric jar; the push-button lid covering the upper casing, the push-button lid being pivotally coupled to the upper casing; a hinge shaft for pivotally coupling the push-button lid to the upper casing, the hinge shaft being inserted in both a hinge shaft hole formed in a lower edge of the push-button lid and a hinge shaft hole formed in a top edge of the upper casing at the back of the upper casing; a pair of hinge springs for biasing the push-button lid and providing elastic opening force for the push-button lid, the hinge springs being fitted over the hinge shaft and spaced out at an interval, and upper arms of the hinge springs are stopped by an arm stopper provided in the push-button lid; and means for adjusting the spring force of the hinge springs by compressing or loosening the hinge springs fitted over the hinge shaft.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Fig. 1 is a rear perspective view of an electric jar having a typical push-button lid; Fig. 2 is a sectional view of a spring-biased hinge structure of the electric jar, with the push-button lid fully opened, taken along the section line A-A of Fig. 1; Fig. 3 is a rear perspective view of an electric jar having a push-button lid in accordance with a preferred embodiment of the present invention; Fig. 4 is a sectional view of a spring-biased hinge structure of the electric jar, with the push-button lid fully opened, taken along the section line B-B of Fig. 1;; Fig. 5 is an eniarged sectional view of a spring force adjusting device of the encircled portion C of Fig. 4; and Fig. 6 is a front view of the spring force adjusting device of Fig. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to Fig. 3, there is shown in a rear perspective view an electric jar having a push-button lid and a spring force adjusting device in accordance with a preferred embodiment of the present invention.

As shown in this drawing, the electric jar designated by the numeral 11 includes an upper casing 13 that is provided on the top of a right-hexadral main body 12. The top of the upper casing 13 is covered with a push-button lid 14 pivotally coupled to the upper casing 13 by a spring-biased hinge structure. In order to couple the lid 14 to the upper casing 13 while allowing the lid 14 to be opened at a predetermined angle with respect to the upper casing 13, the rear center of the lid 14 is pivotally coupled to the upper casing 13 by inserting a hinge shaft 15 into both a hinge shaft hole (not shown) of the lid 14 and a hinge shaft hole (not shown) of the upper casing 13. A pair of hinge springs 16 are fitted over the hinge shaft 15 so that the springs 16 are spaced out at an interval so as to keep desired coupling balance of the lid 14 with respect to the upper casing 13.The hinge spring 16 always biases the lid 14 and provides elastic opening force for the lid 14. In the front of the electric jar 11, the top center of the upper casing 13 is provided with a lid opening push button (not shown).

Turning to Fig. 3 showing the lid coupling part of the electric jar 11 with the lid 14 fully opened in a sectional view taken along the section line B-B of Fig. 3, a top arm 16a of each spring 16 is elastically caught by an arm stopper 18 of the lid 14, thus to elastically keep an opened state of the lid 14 with respect to the upper casing 13. Here, the arm stopper 18 is provided in the interior of the lid 14 so that the stopper 14 is perpendicular to the inner surface of the lid 14. An arm stopper guider 17 vertically placed on the top surface of the main body 12 in the inside of the hinge shaft 15 as shown in Fig. 3. The arm stopper guider 17 having an inclined guide section at its top is adapted for guiding the arm stopper 18 of the lid 14 whenever the lid 14 is opened or closed with respect to the upper casing 13.Formed in the inside of the arm stopper guider 17 is a recess 19 for receiving the arm stopper 18 therein when the lid 14 is closed along with the arm stopper 18 guided by the guider 17.

The spring force adjusting device in accordance with the present invention is shown in detail in Fig. 5. The spring force adjusting device has spring force adjusting means 30.

The spring force adjusting means 30 includes a pair of first supporters 31 of the rod type which vertically extend from the outer surface of the arm stopper guider 17 under the hinge shaft 15. The first supporters 31 are horizontally spaced out at an interval. The spring force adjusting means 30 also includes a second supporter 32 of the plate type which is vertically provided on the top surface of the main body 12 in the outside of the arm stopper guider 17 and under the hinge shaft 15. Lower arms 16b of the hinge springs 16 are received in the space defined between the first supporters 31 so that the lower arms 16b are horizontally spaced apart from each other by a distance. The wall of the second supporter 32 is provided with a pair of threaded holes 34. The threaded holes 34 are horizontally spaced out at an interval. A pair of spring force adjusting screws 35 are threaded into the threaded holes 34 of the second supporter 32 from the exterior to the interior of the second supporter 32 respectively.

In the spring force adjusting device, a space 31a is formed between the first supporters 31 and the second supporter 32 for movably receiving a spring force adjusting lever plate 33 therein. The lever plate 33 is bent at its top section, thus to form a bent portion which is hung on the top surface of the second supporter 32. The lower portion of the lever plate 33 is a flat portion whose inside surface comes into contact with the lower arms 16b of the springs 16. The outside surface of the lower portion of the lever plate 33 comes into contact with the interior ends of the spring force adjusting screws 35.

At this time, the lever plate 33 which comes into contact with the lower arms 16b of the hinge springs 16 has a width somewhat wider than the interval between the lower arms 16b of the springs 16 as shown in Fig. 6. With such wider width, the lever plate 33 reliably transmits the biasing force, caused by tightening motion of the adjusting screws 35, to the lower arms 16b of the hinge springs 16 without malfunction. The first supporters 31 are sufficiently spaced apart from each other so that there is no interference between the lower arms 16b of the springs 16 and the first supporters 31 when inserting the lower arms 16b into the spring force adjusting means 30 through the space between the first supporters 31.

Otherwise stated, the first supporters 31 are positioned at the outside of the insert positions of the lower arms 16b respectively. However, the second supporter 32 has a width similar to that of the lever plate 33 so that the second supporter 32 reliably supports the wider lever plate 33.

As the coiled parts of the hinge springs 16 is fitted over the hinge shaft 15 inserted in the hinge shaft holes of both the lid 14 and the upper casing 13, the upper sections of the lower arms 16b is tightly supported by the fixed hinge shaft 15. In addition, the lower sections of the lower arms 16b are received in the spring force adjusting means 30 between the pair of first supporters 31. In this regard, the lower arms 16b of the hinge springs 16 always come into elastic contact with the inside surface of the lever plate 33.

The electric jar 11 also includes a hook type cover (not shown) that is detachably mounted on the upper casing 13 in the outside of both the first and second supporters 31 and 32.

When pressing the lid opening push button of the electric jar 11, the lid 14 is elastically turned about the hinge shaft 15 owing to the spring force of the hinge springs 16, thus to be opened. At this time, the arm stopper 18 is guided from the recess 19 to a predetermined point or to the top surface of the arm stopper guider 17, at which point the summed spring force of the hinge springs 16 will be balanced with the weight of the lid 14 and which summed spring force will be weakened in accordance with the opening motion of the lid 14.

Meanwhile, when the opened lid 14 is pressed down by force, the lid 14 will be closed. When such lid opening motion and lid closing motion are repeated predetermined times, the hinge springs 16 will lose their predetermined spring force as described for the prior electric jar.

When the hinge springs 16 lose their predetermined spring force due to repeated lid opening and closing motions, the predetermined spring force of the hinge springs 16 can be restored by adjusting the spring force adjusting device of this invention. In order to adjust the spring force using the adjusting device of this invention, the hook type cover is removed from the upper casing 13 so as to expose the heads of the screws 35 inwardly threaded into the holes 34 of the second supporter 32. Thereafter, the screws 35 are tightened with balance so that the lever plate 33 is turned leftward in Fig. 5, thus to cause the lever plate 33 to bias leftward the lower arms 16b of the hinge springs 16 fitted over the hinge shaft 15.As a result of leftward biasing of the lower arms 16b, the hinge springs 16 are compressed so as to restore their predetermined spring force.

On the contrary, when the spring force of the hinge springs 16 exceed the predetermined spring force, the lid 14 will be opened more fast. Such excessive spring force of the springs 16 should be adjusted or reduced in order for assuring the handling safety of the electric jar 11. In order to achieve the above object, the hook type cover is removed from the upper casing 13 so as to expose the heads of the screws 35 to the outside as described above. Thereafter, the screws 35 are loosened with balance so that the lever plate 33 is turned rightward in Fig. 5, thus to cause the lever plate 33 to be turned rightward along with the lower arms 16b of the hinge springs 16 due to the restoring force of the springs 16. The hinge springs 16 are thus appropriately loosened so as to recover their predetermined spring force.

As described above, the spring force adjusting device in accordance with the present invention makes it possible to keep the predetermined appropriate spring force of the lid opening hinge springs. In this regard, this spring force adjusting device can control the biasing force applied on the spring arm stopper during a lid opening motion and keep the appropriate spring force applied on the spring arm stopper The spring force adjusting device keeps the predetermined spring force of hinge springs of the push-button lid of the electric jar, thus to keep desired smooth opening and closing motions of the push-button lid for a long time and to reduce the noise generated in the lid opening motion. This device thus improves the operational reliability of the electric jar with the push-button lid.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

CLAIMS:

1. A device for adjusting hinge spring force of a container with a spring biassed lid comprising: an upper casing provided on the top of a main body of the container; the lid covering the upper casing, said lid being pivotally coupled to the upper casing; a hinge shaft for pivotally coupling the lid to the upper casing, said hinge shaft being inserted in both a hinge shaft hole formed in a lower edge of said lid and a hinge shaft hole formed in a top edge of said upper casing at the back of the upper casing; a pair of hinge springs for biasing said lid and providing elastic opening force for the lid, said hinge springs being fitted over the hinge shaft and spaced out at an interval, , and upper arms of said hinge springs are stopped by an arm stopper provided in the lid; and means for adjusting the spring force of said hinge springs by compressing or loosening the hinge springs fitted over the hinge shaft.

2. A device according to claim 1, wherein the container is an electric jar with a push-button lid.

3. A device according to claim 2, wherein said spring force adjusting means ccncrises: a pair of first supporters vertically extending from an outer surface of an arm stopper guider under the hinge shaft, said first supporters being horizontally spaced out at an interval; a second supporter vertically provided on the top surface of said main body of the electric jar in the outside of the arm stopper guider and under the hinge shaft, said second supporter defining a space between it and said first supporters; a threaded hole provided in the second supporter; a spring force adjusting screw threaded into said threaded hole from the exterior to the interior of the second supporter; and a spring force adjusting lever plate for compressing or loosening said hinge spring in accordance with forward or rearward movement of said spring force adjusting screw, said lever plate being movably received in said space defined between the first supporters and the second supporter.

4. A device according to claim 3, wherein said lever plate includes: a bent top portion hung on the top surface of the second supporter; and a flat lower portion, an inside surface of the lower portion coming into contact with a lower arm of said hinge spring while an outside surface of the lower portion coming into contact with the interior end of the spring force adjusting screw.

5. A device for adjusting the hinge spring force of a container with a spring biassed lid substantially as hereinbefore described with reference to and as shown in Figures 3 to 6 of the accompanying drawings.