US3473166A - Helmets - Google Patents

Description

Get. 21, 1969 J, o, LOBELLE 3,473,166

HELMETS Filed Jan. 29, 1968 3 Sheets-Sheet 1 l/VVE/VTOR f7 2 M43661. .10455 00/40 1095a 5, 05654850 j- B ERIC NOEL M0888 PAUL DERRICK LEONARD 4 051. CHARLES HJ/PHER,

EXECUTOAS T B i 15W, flaw m Mk I Attorney;

Oct. 21, 1969 M. J. o. LOBELLE 3,473,166

HELMETS Filed Jan. 29, 1968 3 Sheets-Sheet 5 52 r mnnnnwggkg 19 "I 72'52756 /& 49

fly ER/C' NOEL M0555 PAUL ficAR/C'K LEONARD N064 CHARLES HYPHER,

EXECUTORS Attorney 5 United States Patent 0 HELMETS Marcel Jules Odilon Lobelle, deceased, late of Slough, England, by Eric Noel Mobhs, Slough, Paul Derrick Leonard, Farnham Common, and Noel Charles Hypher, Slough, England, executors, assignors to M. L. Aviation Company Limited, Slough, England, a British company Filed Jan. 29, 1968, Ser. No. 703,231 Int. Cl. A421) 3/00 US. Cl. 26 7 Claims ABSTRACT OF THE DISCLOSURE A helmet intended particularly to be worn by an airman occupying an aircraft ejection seat. The helmet includes a visor pivoted to the helmet shell and capable of pivoting movement between an upper open position and a lower closed position in which the visor protects the airmans face. The helmet carries a holder for an electrically ignited cartridge. The increased pressure resulting from ignition of the cartridge is transmitted to a chamber containing a pressure responsive member. The member accordingly moves under the influence of the increased pressure and through a visor lowering mechanism automatically lowers the visor to the lower closed position thus protecting the airmans face.

This invention relates to helmets of the kind which incorporate a visor pivoted to the helmet shell serving to protect the wearers face when in the lowered position. Helmets of this type are Worn in aircraft having ejection seats to provide protection against the blasts of air to which the wearer is subjected on ejection. Very often the visor is of a tinted transparent material so that when it is in the lowered position, it also shields the wearers eyes from the sun. However whether the visor is of such material or not, it is quite likely that it may be in the raised position when an emergency requiring immediate ejection occurs. The wearer may not have the time or opportunity to first lower the visor before initiating the ejection, or he may even be unconscious.

British Patent No. 951,817 and my copending US. patent application Ser. No. 592,166 now Patent No. 3,383,706 describe and claim helmets of this kind in which the visor is lowered automatically in the event of ejection under the effect of the G-force which the wearer experiences. No action on the part of the wearer is required and his face is protected almost immediately once he is subjected to a predetermined G-force for instance 10 to 12 G. While the visor therefore provides the necessary protection, it is however lowered after the wearer has started to accelerate upwards and under certain circumstances it may be desirable that it should be lowered slightly earlier.

According to the present invention, a helmet of the kind first discussed, that is to say incorporating a visor pivoted to the helmet shell serving to protect the wearers face when in the lowered position, includes a holder for an electrically ignited cartridge, a chamber in which the pressure rises as a result of ignition of a cartridge in the holder, and a pressure responsive member located within the chamber and connected through mechanism to the visor. On ignition of a cartridge the resultant pressure increase in the chamber causes the pressure responsive member to move with the result that the visor is lowered. This occurs a very short period after the cartridge is ignited and hence on ejection from an aircraft for example, if the cartridge is ignited at the correct instant, the visor reaches the lowered position well before the wearers head emerges from the aircraft. Conveniently cartridge ignition is controlled by the same 3,473,166 Patented Oct. 21, 1969 ICC? handle or switch which sets the seat ejection mechanism in operation so that only a single action on the part of the wearer is required, lowering of the visor and ejection subsequently taking place sequentially.

It can hence be seen that while in the helmets described in our patent and patent application previously mentioned, the visor is lowered as a result of the movement of the wearer on ejection, in helmets in accordance with the present invention the visor is lowered on receipt of an electrical signal. Accordingly such helmets may be worn in other situations besides flying. When used for flying, although in most instances this electrical signal will be produced only when ejection is about to take place, it may of course be produced on other occassions when it is necessary that the visor should be automatically lowered to protect the wearers face at short notice.

Preferably the holder is designed to hold a pair of cartridges adjacent one another so as to provide a safeguard against a cartridge which fails to ignite. The heat of the adjacent ignited cartridge is in general sufficient to ignite the faulty cartridge. The cartridges themselves are normally of the solid fuel type and are sometimes known by other names such as for instance gas pressure actuators or initiators.

Particularly if the visor is also to serve as a shield against the sun, it is important that it should be possible for the wearer to raise and lower it manually. Conveniently therefore the visor lowering mechanism includes a lost-motion connection to permit this.

It is also important that the visor should remain in the lowered position at least until the emergency is over. However due to leakage it is almost certain that the pressure in the chamber will fall and hence it is quite possible that if worn during ejection, the high blasts of air which strike the visor may tend to raise it slightly. This is undesirable giving rise to discomfort and possible injury to the wearer. Preferably therefore the visor has side pieces pivoted to the helmet shell in such a way that when in the lowered position the visor can be moved forwardly away from and rearwardly into contact with the shell. The helmet includes parts which cooperate to prevent the visor being raised when in contact with the shell in which position a spring biasses the visor forwardly. In this helmet, movement of the pressure responsive member to lower the visor subsequently has the effect of drawing the visor rearwardly, that is to say retracting it against the shell. In other words to raise the visor, it is necessary to first move it forwardly out of contact with the shell. Any small fall in pressure in the chamber may allow it to move slightly in a forward direction but it is unlikely to be suflicient to allow the visor to move to the forward position in which the parts move out of cooperation with one another. Hence the visor remains efiectively locked in the lowered position. =It will be understood that an air blast acts rearwardly on the visor and even an upward component will not cause the visor to move forwardly. In contrast the effect of an upword component in the air blast on a helmet not possessing the features just specified is to cause the visor to rise slightly, the amount depending upon the pressure in the chamber.

Once the emergency is over the wearer may wish to raise the visor. Although in time the pressure in the chamber will fall due to natural leakage, the construction may be such that an appreciable period elapses be fore the wearer can pull the visor forward far enough to subsequently raise it. Preferably therefore the helmet includes a lever controlling mechanism which draws the visor forwardly out of contact with the shell. The provision of such mechanism enables the wearer to easily overcome the effect of the increased pressure in the chamber.

By way of example a flying helmet in accordance with the invention will now be described in more detail with reference to the accompanying drawings, in which:

FIGURE 1 is a side elevation of the helmet with the visor in the lowered position which it assumes when lowcred manually;

FIGURE 2 is a rear elevation of the helmet, the lower part of which is shown cut away;

FIGURE 3 is a detail view partly in section of the cartridge holder carried by the helmet shell;

FIGURE 4 is a side elevation corresponding to FIG- URE 1 but showing the visor in the raised position; and

FIGURE 5 is a side elevation corresponding to FIG- URES 1 and 4 but to a larger scale and partly in section showing the visor lowering mechanism which is incorporated in the helmet.

Reference should first be made to FIGURE 1 from which it can be seen that the helmet, which is of the non-pressurized type, has a shell 1 and a visor 2 of a transparent tinted plastics material carried by a pair of side pieces one of which is indicated at 3. The helmet includes what will be referred to as a jaw piece 4 which extends in front of the wearers jaw and supports an oxygen mask (not shown). The jaw piece 4 is hinged at one side to the helmet shell 1 and at the opposite side a catch (not shown), holds the jaw piece in the closed position as illustrated. Full details of such a jaw piece are given in my copending British patent application No. 9,423/66.

The helmet includes a cartridge holder 5 best seen in FIGURES 2 and 3 secured around a pipe 6 which is affixed to the helmet shell by brackets 7. The holder 5 holds a pair of cartridges, one of which is visible at 8 in FIGURE 3. The cartridge 8 is inserted axially into the holder 5 through an aperture 9 into which a plug 10 is subsequently screwed. The plug contains electrical ignition equipment which ignites the cartridge 8 on receipt of an electrical signal received along leads 11. The second cartridge is inserted through the other end of the holder in an identical manner and is ignited on receipt of an electrical signal received along leads 12. Although not illustrated, the leads 11 and 12 are conveniently connected to the electrical control system for the ejection seat mechanism. Operation of the ejection handle in addition to initiating ejection causes electrical signals to pass along the leads 11 and 12 thus igniting both cartridges. Duplicate leads, ignition equipment and cartridges are provided to give increased reliability. As previously indicated if only one cartridge ignites, the heat generated by it is sufficient to ignite the other cartridge.

The gas produced on ignition passes through an aperture 13 into the pipe 6 along which it flows in both directions. As will be described in detail, if the visor is already in the lowered position as illustrated in FIGURE 1, the effect of the gas is to draw it rearwardly so that its edges contact soft material 14 which lines the face opening on the shell 1 and on the jaw piece 4. Accordingly a blast-tight seal is formed so that the wearers face is protected from air blasts and also from rapid pressure changes when his head subsequently emerges from the aircraft. If the visor is in the raised position illustrated in FIGURE 4, the effect of the gas is first to lower it to the lowered position shown in FIGURE 1 after which is then drawn rearwardly as just described.

The mechanism which responds to the pressure increase caused by the gas to lower the visor is identical on either side of the helmet and therefore only that on one side will be described. Referring to FIGURES 1 and 4, it can be seen that the visor sidepiece 3 includes an elongated slot 15 which extends substantially horizontally when the visor is in the lowered position. An outwardly extending pin 16 secured to the shell 1 cooperates with the slot 15 and this arrangement enables the visor to be moved forwardly and rearwardly when in the lowered position. As shown in FIGURE 1 it is in the forward position in which it does not contact the soft material 14.

A cover 17 is secured to the shell 1 over the side piece 3 and an arm 18 is pivoted to the cover 17 about a bolt 19. The lower end of the arm 18 is pivoted to 1 link 20, the other end of which carries a pin 21 which engages with an arcuate slot 22 in the sidepiece 3. The provision of the slot 22 enables the visor to be raised and lowered manually as required. One end of a piston rod 24 engages with the arm 18. The piston rod is moved to the right under the influence of the gas produced on ignition and thereby moves the arm 18 in an anti-clockwise sense moving the link 20 to the right. The pin 21 carried by the link 20 therefore rotates the sidepiece 17 in an anti-clockwise sense if the visor is in the raised position thus lowering the visor and then drawing it rearwardly. If the visor is already in the lowered position, it is merely drawn rearwardly.

The lowering mechanism is shown in detail in FIG- URE 5. As shown in solid outline the constituent parts are in the positions they assume when the visor is in the raised position. As shown in chain-dotted outline. they are in positions corresponding to the visor being in the lowered position after manual lowering, while in chain-double-dotted outline they are in positions corresponding to the visor being in the lowered position after automatic lowering.

The mechanism is best described by considering the visor to be in the raised position. The pressure increase caused by the gas produced on ignition of the cartridges is transmitted along the pipe 6 which is secured in a block 25. A number of passages extend horizontally within the block and are closed by a plate 26 held in place by bolts 27. The pressure increase is transmitted to a passage 23 from which a small passage 29 extends. This passage 29 serves no functional purpose but is used during manufacture to drill another small passage 30. The passage 29 is permanently sealed by a bolt 31. The pressure increase is therefore transmitted along the passage 30 and into what is in effect a cylinder 32. The piston rod 24 previously mentioned carries a piston 33 which is a sliding fit in the cylinder. Hence it can be seen that when the pressure in the cylinder 32 rises, the piston 33 and thus the piston rod 24 are moved to the right.

The right hand end of the piston rod 24 contacts the arm 18. The part which it contacts is a resilient blade 34 secured solely at its lower end to a pin 35 to which the link 20 is pivoted. The pin 35 serves to join two parts 36 and 37 (the part 37 is not shown in FIGURE 5 but only in FIGURES 1 and 4) of which the arm 18 is formed. An annular resilient rubber shock absorber 39 is secured by a bolt 40 to a flange 41 on the part 36 and contacts the blade 34. As the piston rod moves to the right under the elfect of the gas a certain amount of energy is dissipated by the shock absorber 39 thus reducing the speed with which the arm 18 is turned in an anticlockwise sense.

The block 25 has a surface 42 in the shape of an arc of a circle concentric with the pin 16 when the latter is in the position in the slot 15 shown in FIGURE 5. This surface 42 extends from a substantially horizontal plane upwardly through an angle corresponding to that through which the visor moves when it is raised. The side piece 3 carries a lug 43 which cooperates with the surface 42. sliding over the surface as the visor is raised or lowered and thereby maintaining the visor spaced away from the helmet shell.

The surface 42 terminates just short of the horizontal in a recess 44 which is shaped to receive the lug 43. However to do so, a tubular member 45 has to be moved to the right against a biasing force produced by a compression spring 48. This spring is located within a passage 49 in the block 25 and acts on the tubular member 45. The latter has a central web 46 in which is a slot 47. A pin 57 secured to the shell 1 is a sliding fit in the slot 47 and thereby holds the tubular member 45 in the passage 49.

As indicated in FIGURE 5, the tubular member 45 is itself recessed at its outer end so that the lug slides over it to the position indicated as 43. It can be seen that the lug 43' is held within a bracket indicated as 50 secured to the sidepiece 3'.

Manual lowering of the visor causes the pin 21 to slide along the arcuate slot 22. However the length of the slot 22 gives insufiicient lost-motion and hence the arm 18 is pivoted in an anti-clockwise sense to the position indicated as 18.

On cartridge ignition, the arm 18 is pivoted to the position shown as 18". If the visor is in the raised position it is first lowered and then the turning moment applied to it through the link 20 draws the lug 43 inwardly in contact with the tubular member 45 against the eflect of the compression spring 48. Hence the lug 43 moves under the edge 51 of the block 25 and thus prevents the visor being raised.

Eventually the pressure in the cylinder 32 falls due to leakage and the wearer is then able to raise the visor. If he wishes to do this earlier, he pivots a lever '52 in a clockwise sense. At this time the lever is in the position shown in FIGURE 1. As is shown in FIGURE 5, it is pivoted at 53 to a right angled bracket 54 secured at 53 and also by a bolt 55 to the bracket 50'. The lever has a cam surface 56 such that when the lever is pivoted in a clockwise sense, this surface 56 contacts the arcuate bearing surface 42 and draws the lug 43 outwardly from the recess 44. Further movement of the lever 52 raises the vsior to the position shown in FIGURE 4.

I claim:

1. A helmet having a shell, a visor pivoted to said shell and capable of pivoting movement between an upper open position and a lower closed position to protect a wearer of said helmet, holder means carried by said shell for holding an electrically ignited cartridge, means carried by said shell defining a chamber communicating with said holder means, a pressure responsive member located within said chamber, and visor lowering mechanism connected to said pressure responsive member and to said visor, ignition of a cartridge in said holder means resulting in a pressure increase in said chamber whereupon said member is moved and thereby causes said mechanism to lower said visor to said lower closed position.

2. A helmet according to claim 1 in which said visor lowering mechanism includes lost-motion means whereby said visor can be lowered manually.

3. A flying helmet having a shell, a visor pivoted to said shell and capable of pivoting movement between an upper open position and a lower closed position to protect a wearer of said helmet, holder means carried by said shell for holding an electrically ignited cartridge, piston means and cooperating cylinder means and wherein interior of said cylinder means communicates with said holder means and one of said piston means and said cylinder means is carried by said shell, and visor lowering mechanism connected to other of said piston means and said cylinder means and connected to said visor, ignition of a cartridge in said holder means resulting in a pressure increase in said cylinder means whereupon said piston means is moved relatively to said cylinder means and thereby causes said mechanism to lower said visor to said lower closed position.

4. A flying helmet according to claim 3 in which said visor lowering means includes a resiliently acting member which resiliently transmits lowering movement to said visor.

5. A flying helmet according to claim 3 in which visor sidepieces are pivoted to said helmet shell in such a way that when said visor is in said lowered position, said visor can be moved forwardly away from and rearwardly into contact with said shell, and in which said helmet includes parts which cooperate with one another to prevent said visor being raised when in contact with said shell, and spring means which bias said visor out of contact with said shell, said visor lowering mechanism operating to draw said visor rearwardly into contact with said shell after having lowered said visor.

6. A flying helmet according to claim 5 in which a forwardly facing bearing surface having an arcuate profile is carried by said shell and in which a member is carried by one of said sidepieces and contacts said bearing surface except when said visor is in said lowered position.

7. A flying helmet according to claim 6 including visor raising mechanism and a lever controlling said visor raising mechanism, operation of said lever causing said visor to be drawn forwardly out of contact with said shell.

References Cited UNITED STATES PATENTS 3,001,199 9/1961 Williams et al. 2-6 3,050,735 8/1962 Newman et a1. 2-6 3,123,831 3/1964 Wells et a1. 2-9 XR 3,239,843 3/1966 Lobelle 2-6 3,345,642 10/1967 Uminski 2-6 3,383,706 5/1968 Lobelle 2-6 JAMES R. BOLER, Primary Examiner US. Cl. X.R. 128-1427

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