Safety mechanisms for lighters

A safety mechanism for lighters includes a lighter body having a safety lever that is actuated from outside the body by acting upon a tongue passing through a L-shaped window in the body. The safety lever, which is mounted as a torsion spring, normally occupies a position in the L-shaped window with the tongue at the end of the horizontal leg of the window. In that position, the pushbutton and the upper edge of the safety lever are in substantial abutment and operation of the lighter is not possible. When the tongue is moved to the other end of the L-shaped window, the tongue is in alignment with a recess provided in the pushbutton such that the pushbutton is free to move. After lighting is accomplished and the pushbutton is released, the tongue recovers automatically to the safety position.

BACKGROUND OF THE INVENTION 
Presently, all lighters of the piezoelectric lighting type, as well as the 
pyrophoric or battery types, etc., contemplate an easy and rapid lighting 
device, improved in that it is only necessary to exert simple pressure on 
a pushbutton. 
On one hand, it implies an advantage in lighting due to its extreme speed 
of operation. However, there is a noteworthy lack of safety for the user 
who carries such a device, since in an unforeseeable involuntary action, 
the lighter can light up accidentally, or at least give rise to a gas leak 
with the consequences that such a leak causes. 
SUMMARY OF THE INVENTION 
The present invention refers to a safety mechanism for lighters that 
assures that the lighter cannot be lit accidentally. The lighter requires 
the user's total attention every time he wishes to light it. He must pay 
attention to the lighter since it always has to be conditioned or preset 
before lighting it. The mechanism automatically returns to its blocking or 
safe position after this lighting operation. 
With this mechanism, it is impossible that the lighter light up 
accidentally due to an involuntary pressure exerted on the pushbutton when 
the lighter is kept in one's pocket, especially when the lighter is of the 
piezoelectric lighting type. 
In order to preset the mechanism, it is necessary to effect two movements 
perpendicular to each other of an element defined as a safety lever. This 
requirement is very effective to prevent the lighter being lit by 
children. 
Another object of the invention is to prevent a condition where the lighter 
cannot be lit due to a lack of recovery of the pushbutton after a first 
pushbutton actuation. This failure to recover initial or standby position 
can happen due to an accumulation of dirt, or simply due to sand in the 
mechanism. 
In order to obtain the proposed objectives, the safety mechanism for 
lighters, which makes up the object of the invention, and which is 
especially used when the lighting system is of the piezoelectric type, 
includes a safety lever having a tongue which passes through an L-shaped 
window in the body of the lighter. That is, the window is in the wall of 
the housing wherein the pushbutton for lighting moves and is vertically 
guided. The safety lever is actuated from outside the housing. 
The L-shaped window is oriented with the vertical leg of the L-shape being 
parallel to the motion of the pushbutton in operation, and the horizontal 
leg of the L-shape is transverse to the vertical leg and to the motion of 
the pushbutton. 
The safety lever is normally positioned with its tongue located at the free 
closed end of the horizontal leg of the L-shaped window. This position 
corresponds to the safety or block position because the pushbutton cannot 
move vertically as the top edge of the safety lever is in contact with the 
bottom edge of the pushbutton. The tongue is automatically biased so that 
it occupies this blocking or safety position. 
In order to preset the mechanism so that lighting may be effected, it is 
necessary to move the tongue from the free closed end of the horizontal 
leg in two orthogonal movements so that it leaves the free end of the 
horizontal legs moves to the joint between the vertical and horizontal 
legs and then moves along the vertical leg to the free closed end of that 
vertical leg. When the tongue is located at the free end of the vertical 
leg, the top edge of the safety lever no longer abuts a bottom edge of the 
pushbutton but is located in a position which faces a recess that exists 
in the pushbutton. Thus, it is possible to move the pushbutton downward, 
that is, toward the horizontal leg of the L-shape without interference 
with the safety lever. 
After using the flame of the lighter, the pushbutton is released, the 
safety lever automatically returns to the blocking or safety position 
because approaching the end of the operational stroke of the pushbutton, 
in the act of lighting, the tongue of the safety lever is acted upon by 
the pushbutton itself and is moved vertically from the free closed end of 
the vertical leg in the L-shaped window until it is at the joint aligned 
with the horizontal leg of the L-shaped window. When the pushbutton 
returns to its original position, the safety lever remains in alignment 
with the horizontal leg of the window. At this position, the automatic 
biasing of the tongue forces the tongue to its original starting position 
at the free closed end of the horizontal leg of the window. 
The pushbutton has vertically oriented grooves in its side wall, that is, 
oriented in the direction of pushbutton motion, in order to reduce the 
contact surface between the pushbutton and the housing or body of the 
lighter and reduce friction so that recovery of the pushbutton is assured. 
Thus, closing of the gas valve in the lighter is also properly effected 
and motion of the safety lever to the safety position is effectively 
accomplished.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
With reference to the Figures, the safety mechanism for lighters in 
accordance with the invention includes a safety lever 1 having a geometry 
best illustrated in FIG. 4. At one end of the lever 1 is a protruding 
tongue 3 and at the other end of the elongated lever 1 are two feet 7 
separated by a groove. The lever is made such that when the feet 7 are 
constrained, the tongue 3 may moved, thereby subjecting the lever to 
torsional stress. 
The safety lever 1 is positioned in the inside of the body 2 of the lighter 
in such a way that the tongue 3 extends from the body 2 of the lighter 
through an L-shaped window 4 at the rear of the lighter. 
In the position shown in FIG. 1, movement of the pushbutton 5 into the body 
2 in the longitudinal direction is blocked and production of a spark 
coming from a piezoelectric device and also the opening of a gas valve, 
are avoided. In this blocked or safety position, as illustrated in FIG. 1, 
the tongue 3 is located in the horizontal leg of the L-shaped window. In 
this position, as illustrated in FIG. 2, the lower edge of the pushbutton 
5 is practically in contact with the upper edge of the safety lever 1, 
thus preventing the downward motion of the pushbutton, at least, while the 
control tongue 3 is in the position illustrated in FIG. 1. 
The pushbutton 5 is provided with recesses that accommodate the safety 
lever 1 when the lever 1 is placed in the position where lighting may be 
effected. 
This lighting position of the safety lever 1 is obtained upon moving the 
control tongue in two perpendicular directions following the outline of 
the L-shaped window 4 as indicated by the arrows of FIG. 1. When starting 
from the blocking position illustrated in FIG. 1, the control tongue 3 is 
accidentally pressed toward the left (FIG. 1), upon removal of the cause 
of such displacement, the tongue 3 and therefore the lever 1 returns to 
its initial blocking or safety position (FIG. 1). This occurs because in 
moving out of the horizontal leg of the window, a torsional stress is 
induced by turning of the tongue 3 relative to the feet 7 that are 
constrained in the body by a constraint 11. If the accidentally applied 
force only moves the tongue 3 of the lever 1 along the horizontal leg in 
the window 4, then upon release of the accidental force, the torsion in 
the lever 1 returns the lever 1 to the position shown in FIG. 1 with the 
tongue at the free closed end of the horizontal window leg. 
An intentional preparation or presetting of the lighter so that lighting 
can be effected requires first that the control tongue 3 be moved 
horizontally in the horizontal leg of the L-shaped window so that it comes 
into alignment with the vertical leg of the window 4. Then, the tongue is 
pushed upward until it is blocked by the free closed end of the vertical 
leg of the window. In this position, the top edge of the safety lever 1 is 
no longer opposed to the bottom edge of the pushbutton 5 but rather is 
positioned in alignment with a recess 6 (FIG. 5) formed in the bottom of 
the pushbutton 5. Thus, the recess 6 provides clearance between the safety 
lever 1 and the pushbutton 5 so that the pushbutton can be moved 
vertically downward toward the window. 
During lighting, when the pushbutton 5 moves down, there is a moment when 
the top wall 8 of the recess 6 contacts the top edge of the safety lever 1 
such that further downward motion of the pushbutton 5 forces the lever 1 
to follow and move the tongue 3 downward along the vertical leg of the 
L-shaped window 4. When the pushbutton 5 is depressed, the side wall 9 of 
the recess 6 prevents the tongue 3 from re-entering the horizontal leg of 
the L-shaped window. The side of the lever 1 rests against the sidewall 9. 
When the pushbutton returns to its original upward position, the surface 9 
no longer obstructs the lever tongue 3, and the lever elastically reverts 
to the position indicated in FIG. 1 by the tongue moving along the 
horizontal leg, to the free closed end, of the L-shaped window 4. The 
lever 1 returns automatically to its blocking or safety position after use 
of the lighter, thus fulfilling the required safety function. This occurs 
as a result of the torsional stress to which the lever 1 was previously 
subjected in presetting the lighter for operation. 
The pushbutton 5 includes vertical grooves 10 on its sides to eliminate 
friction during movement of the pushbutton as described above and to 
permit easy recovery to the starting position. Thus, closing the gas valve 
and entry of the tongue 3 of the lever 1 to the blocking position are 
assured.