CHILD RESISTANT GAS LIGHTERS

Abstract: The invention relates to a roll and press gas lighter which is rendered child resistant by frictionally retarding the wheel assembly, making it difficult for a child to rotate it. The wheel assembly may have a serrated axle rotating in a serrated bearing; the periphery or sides of the thumbwheel may have projections which engage with the lever or lighter body. The wheel assembly may be formed in two parts, urged apart by an internal spring so as to frictionally engage in frustoconical bearings; alternatively the wheel assembly may rotate frictionally around a fixed axle. The wheel assembly may be retarded by a rubber wheel or a fixed leaf spring. Alternatively the flint may be provided with a strong spring to retard the sparkwheel, and the sparkwheel may be indented to engage with the flint.

Description: Child Resistant Gas Lighters The present invention relates to gas lighters of the "roll and press" type, and more specifically to child resistant lighters. Roll and press gas lighters of the type used for lighting cigarettes are well known. A lighter of this type has a gas reservoir, a gas regulation system including a valve open/close system lifted and closed by a lever, and a wheel ignition mechanism. The ignition mechanism preferably comprises a sparkwheel disposed midway between two thumb-wheels whose diameter is larger than the spark-wheel. The spark-wheel rubs frictionally against a flint when rotated, in order to project sparks above the opened burner and therefore to produce a flame. It is important to prevent the use of such lighters by children under the age of 5 years. Since 1994, the US authorities have specified the test for whether a lighter is child resistant by the CPSC Rules & Regulations. Many child resistant lighter mechanisms have been proposed. There are two broad techniques for child resistance. Most systems use a lever mechanism having two positions; one where the mechanism is prevented from working (the lighter cannot function properly), and a second where the mechanism is manipulated (by displacement, pivoting, etc.) to a position where the lighter can function and produce a flame. The mechanism must reset automatically to its original "safe" position after the lighter has been used. In the other type of mechanism, the unlocking system is in the wheel assembly area in order to minimize the time the user takes to learn how to operate it. Usually, these systems do not use purely mechanical interlocking means as described above, but rather involve properties or parts which make the operation difficult for children while still easy to operate by adults. An example of the latter type of system is described in WO 98/04869, PCT/IB97/00860. In this, the spark- wheel of the lighter has thumb-wheels on each side which have a slightly greater diameter, so that the user's finger engages with the thumb-wheels. The thumb-wheels are rotatable independently of the spark- wheel, but sufficient pressure on the thumb-wheels engages them frictionally with the spark-wheel so that the spark-wheel rotates with the thumb-wheels. Another example is Zellweger, US 5 096 414. In this, the spark-wheel of the lighter has thumb-wheels on each side which have a slightly greater diameter, rotatable independently of the spark-wheel. To operate the lighter, the user has to press hard enough for the pulp of their fmger to bulge down between the thumb-wheels and engage with the spark-wheel. A further example is Hwang, US 5 547 370. In this, the spark-wheel of the lighter has thumb-wheels on each side which have a slightly greater diameter, so that the user's finger engages with the thumb-wheels. The thumb-wheels are rotatable independently of the spark-wheel, but sufficient pressure on the thumb-wheels engages them with the spark-wheel so that the spark-wheel rotates with the thumb-wheels. The engagement is achieved by providing the spark-wheel with a polygonal shaft and the thumb-wheels with polygonal bores of slightly larger size, so that the thumb-wheels can rotate around the spark-wheel shaft but will engage with it under radial pressure. In all these systems, the wheel assembly is mounted such that substantial pressure is required to rotate the spark-wheel against the flint. As a result, it is difficult for a child to operate the lighter, as children have difficulty in exerting sufficient force. Thus while it is relatively easy for a child to rotate the thumbwheels, the child finds it difficult to engage the spark-wheel. With the known lighters discussed above, the fact that the thumb-wheels can be rotated easily tempts the child to continue to play with the lighter, and sufficient pressure to operate it may accidentally be achieved during such continued play. Also the number and arrangement of components required in these known lighters results in a higher manufacturing cost compared to conventional non child safety lighters. The object of the present invention is to provide an improved gas lighter which alleviates or overcomes these problems. Accordingly one aspect of the present invention provides a child resistant lighter of the roll and press type, comprising a wheel assembly mounted on the lighter body and including at least one thumb-wheel and a spark-wheel engaging against a flint, wherein the wheel assembly is mounted such that substantial pressure is required to rotate the spark-wheel against the flint, characterized in that the spark-wheel is attached to the thumb-wheel(s) and the wheel assembly as a whole is mounted on the body and is in frictional engagement with another component of the lighter. Another aspect of the present invention provides a child resistant lighter of the roll and press type, comprising a wheel assembly mounted on the lighter body and including at least one thumb-wheel and a spark-wheel engaging against a flint, wherein the wheel assembly is mounted such that substantial pressure is required to rotate the spark-wheel against the flint, characterized in that the spark- wheel is attached to the thumb-wheel(s) and the spark- wheel and/or the thumb wheel is in frictional engagement with another component of the lighter, said other component being fixed to the lighter body. In the present lighter, the child will find it difficult to achieve any rotation of the wheel assembly. A child playing with the present lighter will lose interest relatively quickly. The present invention, in its preferred embodiment, provides a child resistant lighter which can conveniently be operated and which requires no significant learning effort on the part of the user, and in which the possibility of inadvertent ignition other than by the correct specified method is small. Several forms of lighter embodying the invention will now be described, by way of example, with reference to the drawings, in which: Fig. 1 a is an end view of the spark wheel assembly of a first form of lighter according to the invention; Fig. lb is a side view of fig. la; Fig. 2a is an end view of the wheel assembly of a second form of lighter according to the invention; Fig. 2b is a side view of fig. 2a; Fig. 2c is a side view of a further form of a lighter of the invention in first position of the thumb wheel; Fig. 2d is the side view of fig. 2c in a second position of the thumb wheel; Fig. 3a is an end view of the wheel assembly of a further form of lighter according to the invention; Fig. 3b is a side view of fig. 3a; Fig. 4a is a side view of a further form of a lighter of the invention; Fig. 4b is an end view of fig. 4a; Fig. 5a is a side view of a further form of a lighter of the invention; Fig. 5b is an end view of fig. 5a; Fig. 6a is an end view of the wheel assembly of a further form of a lighter according to the invention; Fig. 6b is a side view of fig. 6a; Fig. 6c is an enlarged view of fig. 6b; Fig. 7a is an end view of the wheel assembly of a further form of lighter according to the invention; Fig. 7b is a side view of fig. 7a; Fig. 7c is an enlarged view of fig. 7b; Fig. 8a is an end view of the wheel assembly of a further form of lighter according to the invention; Fig. 8b is a side view of fig. 8a, and Fig. 8c is an enlarged view of fig. 8b. Referring to Figs, la and lb, the first form of lighter has a gas reservoir 10, a gas regulation system including a valve open/close system lifted and closed by a lever (not shown), and a wheel ignition mechanism 13 comprising a wheel assembly 14 and a flint and spring 17, 19. The wheel assembly 14 comprises a spark- wheel 15 disposed midway between two thumb-wheels 16 whose diameter is larger than the spark-wheel. The spark-wheel rubs frictionally against a flint 17 when rotated, in order to project sparks above the opened burner or jet and therefore to produce a flame. The flint 17 is urged against the spark- wheel by a spring 19. The wheel assembly 14 is mounted in a pair of ears 30 of the lighter. Specifically, the wheel assembly comprises the spark- wheel 15 and the thumbwheels 16 mounted on an axle 31 which is supported in a pair of bearing holes 32 in the ears 30. In order to activate the lighter, the user has to rotate the wheel assembly 14. This causes the spark-wheel 15 to rub against the flint 17 and so produce sparks. The user's thumb-will then contact and press the lever, so opening the gas valve. Gas will emerge from the burner and be lit by the sparks from the flint. As is shown in Figs, la and lb, the shaft 31 of the wheel assembly 13 is corrugated 33, as are the bearing holes 32 in the ears 30. There is therefore a macroscopic frictional engagement between the shaft and the bearing holes, and a force large enough to overcome this friction must be exerted before the wheel assembly will turn. These corresponding corrugations or serrations 33 are configured so that ignition will be too difficult for a child to achieve but will be possible for an adult to achieve. Figs. 2a and 2b show the second form of lighter the corresponding parts are show by the same numerical identifiers. In this lighter, the thumb-wheels 16 comprise extended teeth 40 which engage on a friction pad or indentation 41 located below it, preferably on the upper surface of the lever 12. The thumbwheels 16 are in permanent engagement with this indentation 41 ; for example, the lever 12 may be resiliently mounted to press upwards against the thumbwheels. As before, the frictional engagement of the thumb-wheel prevents the wheel assembly from rotating until sufficient force is applied to overcome the friction. In this embodiment the axles and supporting holes in the ears of the lighter are the same as a conventional lighter. The lever, which is conventionally made from plastic material may include a protective plate of steel, zamac or other suitable material, on that part of the lever which engages with the indentation 41 or friction pad so that the lever is not worn unduly during use and so that the engagement can be controlled or tuned to provide the desired child resistant properties. This protective plate could be fixed or resiliently mounted and could have a particular shape such as a profiled notch to aid the control of the frictional engagement with the indentations or friction pads of the wheel assembly 14. Referring now to figs. 2c and 2d a further embodiment of the invention is shown in which the wheel assembly 14 is mounted so that it has to be pressed in before the sufficient force can be imparted on the thumbwheel to cause it to rotate. The axle shafts 31 of the wheel assembly 14 are located in slot-like holes 32a in the ears of the lighter body. Thus in the rest position as shown in fig. 2c the wheel assembly 14 is urged upwards by the flint spring 19. When the user operates the lighter the users thumb is pressed on the thumbwheel 16 which presses down the wheel assembly against the spring force of the flint spring 18 because the axle 31 is free to move in the slot 32a. This downwards movement of the wheel assembly stops when the thumb wheel 16 abuts against the upper surface 12a of the lever part 12. This occurs before the axle 31 reaches the end of the slot 32a. At this point, although the user is able to impart sufficient downward pressure on the thumbwheel to grip it sufficiently to rotate it, nevertheless this rotation is impeded by the frictional force between the outside, serrated surface of the thumb wheel and the upper surface of the lever part 12. The frictional engagement between the thumbwheel and the lever part 12 can be controlled to the extent that the lighter will operate as a child resistant lighter. The sparks would then be generated normally by the rotation of the spark wheel 15 against the flint 17 when the lighter is operated by an adult. The upper surface of the lever part 12 comprises a frictional contacting surface 12a which may be of a different material or coating than a conventional lever. Figs. 3a and 3b show an ignition mechanism of a third form of lighter. The thumb-wheel has a friction pads 50 arranged adjacent to the shaft 31 , and the ear 30 has a friction bearing surface 51 on its inner surface around the bearing hole 32 and facing the thumb-wheel. There is only one friction pad 50 shown in this embodiment but any suitable number could be used. Also the friction bearing surface 51 on the inside of the ear 30 could be in the form of a discrete pad and preferably at least as many as of these pads are used so that there is not sufficient angular rotation between adjacent pads to operate the lighter without the pads being engaged. In the embodiment shown the two support ears 30 bear resiliently inwards against the wheel assembly 13 to provide a force between the friction pad 50 and the friction ring 51. The friction pad 50 therefore engages against the friction ring 51 to provide the frictional force which restrains the wheel assembly from rotating until sufficient force is applied. The friction pad(s) and friction ring may be interchanged between the thumb-wheel and the support ear, and/or two friction rings may be used instead of a friction ring and a single or set of friction pad(s). The friction ring and pad(s), or pair of friction rings, may be provided on one or both sides of the wheel assembly. Also the friction pads could either be arranged on the thumb wheel at a diameter in relation to the ear which means that the pads disengage from the friction rings on the ear for part of the cycle as shown in figs 3a and 3b, or alternatively the friction pads are arranged on a diameter in relation to the extent of the ear 30 which is always with in the ear 30 such that there is continuous engagement between the friction pads and the friction ring. The friction ring or pad located on the ear 30 is conveniently made from the same plastic material as the ear and may be integrally moulded therewith. Alternatively the friction pad or ring may be made from a more hard wearing material such as zamac or steel in the form of an inserted plate. Figs. 4a and 4b are a side view and end view respectively of the wheel assembly and support ears of the fourth form of lighter. In this arrangement, the ends of the shaft 31 and the bearing holes 32 are conical, as shown, and their engaging surfaces are coated or treated so that there is substantial friction between them. The two ends of the shaft 31 are provided on separate parts 35, 36 with a spring 34 arranged between them and urging them apart and outwards against the ears 30. This generates the required friction between the corresponding conical surfaces. The separate parts 35, 36 having corresponding cylindrical central portions which slide with respect to each other. The outer cylindrical portion having a conventional spark wheel coil 37 arranged around it. As in the previous embodiment, the support ears 30 bear resiliently inwards to provide the required frictional force between them and the wheel assembly, so that the wheel assembly will only turn if sufficient force is applied to it. Figs 5a and 5b are side and end views of a further embodiment of the invention in which the ends of the supporting axles or stub shafts 31 are square shaped in cross section and are fitted in correspondingly square shaped holes in the ear extensions 30 of the body of the lighter. The stub shafts form an integral shaft part 38 which is therefore not able to rotate. Instead the wheel assembly 14 is arranged to rotate about this integral shaft 38. This arrangement of the wheel assembly frictionally engaging the shaft 38 makes the rotation of the wheel assembly more difficult than a conventional arrangement and to such an extent that it can be used to provide a child resistant lighter. Furthermore the use of particular materials in the corresponding contacting surfaces 39 of the outside shaft 31 and the inside of the wheel assembly 14 enable the friction properties and the child resistant properties to be controlled. A further embodiment of the invention is show in the end and side views of figs 6a and 6b as well as in the enlarged side view fig. 6c. In this embodiment a rubber wheel 60 is provided which extends across the wheel assembly 14 and acts against both the thumb wheels 16 providing a resistance to the rotation of the wheel assembly 14. Additional force is required on the thumb wheel to rotate the wheel assembly 14 in order to overcome the deformation of the rubber wheel 60. The wheel assembly comprises a conventional spark wheel in the form of a coil with two thumb wheels arranged either side of it. Both the wheel assembly 14 and the rubber wheel 60 are fitted in holes in the ear extensions 30 of the lighter body. Figs 7a, 7b and 7c show the corresponding end view, side view and enlarged side view of a further embodiment of the invention. This embodiment is similar to the previous embodiment except that a leaf spring 70 is provided, which extends across the wheel assembly and acts against the thumb wheel 16. The leaf spring is provided with a lateral extension at its end which co-operates with the teeth of the thumb wheel 16 and impedes rotation of the thumb wheel. Thus an additional force is required on the thumb wheel in order to rotate the wheel assembly 14. The leaf spring is mounted in the extension ears of the lighter body. The leaf spring 70, as with the rubber wheel of the previous embodiment could also act on the spark wheel 15 rather than or as well as the thumb wheel 16. Figs 8a, 8b and 8c show the corresponding end view, side view and enlarged side view of a further embodiment of the invention. This embodiment also has a leaf spring 80 which extends across the wheel assembly and acts against the wheel assembly to resist its movement. In this embodiment however the leaf spring 80 is provided with an engaging shoe 81 at its free end which engages against corresponding engaging surfaces 82 on the wheel assembly 14. The engaging surfaces 82 are provided between the spark wheel coil 15 and the thumb wheels 16. The engaging shoe 81 and the engaging surfaces 82 are correspondingly curved about the rotating axis. The spring force of the leaf spring 80 provides an engaging force between the engaging surfaces 82 and the engaging shoe, rather like a brake shoe, and this force provides frictional resistance to the rotation of the wheel assembly which makes operation of the lighter more difficult for a child. In all of the above embodiments the flint spring 19 presses up against the flint 17 which engages against the underside of the spark wheel 15 such that when the spark wheel rotates the rubbing between the outer surface of the spark wheel and the upper end of the flint 19 causes sparks to be created and to directed towards the jet of gas flowing from the burner. In a further embodiment of the invention the flint spring 19 provides such a large force against the flint 17 that the flint presses against the spring with such force that a child is unable to cause the spark wheel to be rotated, (within the meaning of the CPSC Rules & Regulations referred to earlier in this specification), but which nevertheless permit the spark wheel to be rotated by an adult. Furthermore the spark wheel may be provided with indentations on its outside surface of such a size and orientation that either on their own or combined with the additional spring force acting on the flint also achieve the desired child resistancy effect. These effects may be combined with any of the other features described above to achieve a lighter with a satisfactory child resistant performance and acceptable ease of use for an adult. It will be appreciated that many other embodiments may be envisaged which are within in the scope of the present invention which is defined by the appended claims. In particular a child resistant lighter may be provided by the present invention which includes any combination of one or more of the features described in any of the above embodiments.

Claims: Claims A child resistant lighter of the roll and press type, comprising a wheel assembly mounted on the lighter body and including at least one thumbwheel and a spark-wheel engaging against a flint, wherein the wheel assembly is mounted such that substantial pressure is required to rotate the spark- wheel against the flint, characterized in that the spark- wheel is attached to the thumb-wheel(s) and the wheel assembly as a whole is mounted on the body and is in frictional engagement with another component of the lighter. A child resistant lighter of the roll and press type, comprising a wheel assembly mounted on the lighter body and including at least one thumb- wheel and a spark-wheel engaging against a flint, wherein the wheel assembly is mounted such that substantial pressure is required to rotate the spark-wheel against the flint, characterized in that the spark-wheel is attached to the thumb-wheel(s) and the spark-wheel and/or the thumb wheel is in frictional engagement with another component of the lighter, said other component being fixed to the lighter body. A child resistant lighter according to claim 1 , characterized in that frictional engagement means are provided on either or both of the wheel assembly and the body of the lighter of a part thereof. A child resistant lighter according to any preceding claim, characterized in that the frictional engagement means are in the form of a friction pad. A child resistant lighter according to any preceding claim, characterized in that the frictional engagement means are arranged as at least three separate means arranged evenly around the perimeter of the wheel assembly. A lighter according to any preceding claim, wherein the wheel assembly is mounted on a shaft with corrugations and which engages in corrugated bearings. A lighter according to any preceding claim wherein the thumb-wheel(s) engage with a friction pad mounted therebelow. A lighter according to any preceding claim wherein the wheel assembly is mounted between a pair of support ears which bear resiliently inwards against the wheel assembly, and the side face of the thumb-wheel(s) has friction means bearing against corresponding friction means on the facing face of the adjacent support ear. A lighter according to any preceding claim wherein the wheel assembly is mounted on a shaft between a pair of support ears which bear resiliently inwards against the wheel assembly, and the shaft has conical ends which bear frictionally against corresponding conical bearings in the support ears. A lighter substantially as herein described and illustrated. Any novel and inventive feature or combination of features specifically disclosed herein within the meaning of Article 4H of the International Convention (Paris Convention).

Inventors: SEWALT CAREL, SEWALT, CAREL
Applicants: SEWALT CAREL, SWEDISH MATCH LIGHTERS BV, SEWALT, CAREL, SWEDISH MATCH LIGHTERS B.V.
Application year: 2001
Main classification: F23Q2
IPC codes: F23Q2