the headgear 10 of this invention is shown in fig1 – 3 , and comprises an upper helmet portion 11 defining an integrally formed , outer central reinforcing ridge 12 and a corresponding interior reinforcing grid area 13 . into the grid area 13 are mounted removable or rechargeable lithium ion battery packs 14 and 15 which connect to a circuit board 16 , the circuit itself being shown in fig4 . wire connections from the batteries to the circuit board and to the led arrays are shown in fig5 . a rearwardly installed led array 17 is mounted on the upper helmet portion 11 and are connected to the circuit board and driven by the battery packs . the led array 17 is shielded by a transparent acrylic sheet 18 mounted on the exterior of the upper helmet 11 . the front area of the upper helmet 11 is provided with an enclosure 20 shielded by a curved , transparent acrylic sheet 21 which protects an enclosed , front facing led array 22 . an interfitting helmet portion 25 is configured to interlock with the upper helmet portion 11 , the two helmet portions being secured together vertically by screws 26 . the helmet portion 25 defines a flat portion 27 which registers with grid area 13 and contacts the lower sides of the battery packs 14 , 15 thereby securing the battery packs in place . as indicated , the front area of the helmet 25 defines the enclosure 20 into which the front facing led array 22 is mounted . the led array 22 is driven through the circuit board 16 from the battery packs 14 and 15 as shown in fig4 , similarly to the led array 17 and the circuit of fig4 , which will be described , infra . fig3 – 5 show an on - off switch 28 connected to the circuit board 16 and circuit of this invention . fig3 also shows a charging outlet pin 29 for the battery packs 14 and 15 , the charging pin being adjacent to the on - off switch 28 . the batteries also may be removed for recharging or replacement . an integrally formed , reinforcing wrap - around section 11 a on the helmet portion 11 defines bores 30 coinciding with bores ( not shown ) in the helmet portion 25 through which pass screws 31 which horizontally secure the helmet portions 11 and 25 together . the screws 26 and 31 thereby secure the helmet portions 11 and 25 both vertically and horizontally . if desired , an edge liner 25 a of injection molded polypropylene may be employed to engage the edges between the helmet portions 11 and 25 , and thereby effect additional securement between the two helmets . as shown in fig3 , a protective foam head enclosure 32 such as constructed from polyurethane or polystyrene foam is provided to cushion the wearer &# 39 ; s head from impact against the much harder abs plastic materials of both the helmet portions 11 and 25 . similar bores ( not shown ) in the head enclosure 32 register with the bores 30 and enable the helmet portions 11 and 25 and the head enclosure to be secured together using the screws 31 . the circuit shown in fig4 and 5 enables a relatively long and uniform battery power output before charging is required . the lithium ion batteries jp 1 and jp 3 shown in fig4 and 5 each deliver about 6600 milliamps at 7 . 2 volts and are isolated from each other by a diode d 3 . when the on - off switch 28 ( fig3 ) is turned on at jp 1 , the batteries jp 1 and jp 3 will turn on a comparator such as an op amp comparator jp 2 , e . g . an lm358 . the comparator jp 2 shows a direct coupled amplifier configuration driven from the battery jp 1 through transistors pnp q 1 and npn q 2 , and through the coupling resistance r 7 to the input pin 1 of jp 2 . resistances r 1 , r 2 , r 3 , r 6 / r 4 respectively will protect a zener d 1 , q 1 , r 5 - jp 2 and led arrays d 2 ( 17 , 22 ) from excessive current / voltage . battery power from jp 3 is applied to the voltage divider r 5 and then to pin 2 of jp 2 , while pins 3 , 4 of jp 2 are both at ground . obviously , the op amp comparator jp 2 is driven by both batteries jp 1 and jp 3 . capacitor c 1 and resistance r 8 are both grounded , and provide ripple filtering , and r 8 also shunts voltage from pin 3 of the jp 2 to the zener d 1 . jp 2 ( at pin 8 ) also drives the zener which functions as a shunt to maintain the load voltage constant for changing current / voltage variations due to running down of the batteries . in the reverse conduction condition as shown , the zener d 1 also reduces ripple voltage . when the switch 28 ( fig3 ) is turned on at jp 1 , and voltage from the voltage divider r 5 exceeds the pin 3 reference voltage , the comparator jp 2 ( lm358 ) will turn on , and hence transistors q 1 and q 2 ( driven from jp 1 and jp 3 ) will then turn on the led arrays d 2 ( 17 , 22 ). typically , the lumen output of the present device for about 93 leds is about 4000 mcd @ 20 milliamps for 5 – 5½ hours using 7 . 2 volt batteries . moreover , the device of this invention frees up the wearer &# 39 ; s hands when viewing an operating field , especially in an emergency situation . it will be appreciated that while a zener diode is preferred for use in the circuit described , other semiconductor devices with similar turn - on characteristics may be utilized , and they are described in the “ scr manual , including triacs and other thyristors ” sixth edition , 1979 by general electric , and incorporated herein , by reference . additionally , the circuit of this invention may be employed for illuminating purposes other than in a helmet , such as an led array in a flashlight ; to function as a traffic signal ; as an led turn on device used with an alarm detection system ; and so forth .
a three - component , protective headgear or helmet is provided with a battery - powered led head lamp , which may be used by construction workers , search and rescue persons , cyclists , police , fireman , and the like . the battery may be replaceable or rechargeable and has long - term , uniform output characteristics driven by unique circuitry .