US20070226865A1

US20070226865A1 - Arrangement for securing a hearing protector to a helmet and a helmet with such an arrangement

Info

Publication number: US20070226865A1
Application number: US11/682,208
Authority: US
Inventors: Mats Lindgren
Original assignee: Kompositprodukter Vikmanshyttan AB
Current assignee: Kompositprodukter Vikmanshyttan AB
Priority date: 2006-03-10
Filing date: 2007-03-05
Publication date: 2007-10-04
Also published as: SE528779C2; DE102007011110A1; SE0600541L

Abstract

Arrangement for securing a hearing protector to a helmet, which arrangement comprises a cap holder piece (102) and a helmet piece (101). The cap holder piece contains a rotary plate (103), a bistable element (104) and a cap holder element (105), which is secured by means of the bistable element to the rotary plate to allow a hearing protection, secured to the cap holder element, to take up a tilted out and a tilted in position relative to the rotary plate. The helmet piece comprises means (112, 112′) of attachment to a helmet and a receiving piece (111), in which the rotary plate is secured, able to turn about an axis of rotation, which receiving piece includes a resilient tongue (113) essentially parallel to the axis of rotation and a first stop piece (116) which, under the action of the resilient tongue and in cooperation with a second stop piece (132) arranged on the rotary plate, releasably maintains the rotary plate in a first rotational position relative to the receiving piece. To prevent the cap holder piece from accidentally leaving the first rotational position, the arrangement includes a first projection (119) extending from the receiving piece essentially parallel to the axis of rotation, which in the first rotational position limits the motion of the rotary plate toward the resilient tongue by thrusting against the cap holder piece.

Description

FIELD OF THE INVENTION

The invention concerns an arrangement for securing a hearing protector to a helmet according to the preamble of patent claim 1. The invention also concerns a helmet with such an arrangement.
1. Background
Nowadays, thanks to laws and regulations, many work situations require the employer to provide both a protective helmet and hearing protection to guard against various risks to the personnel during their work. One example is felling of trees with a chain saw. Most of the manufacturers of protective helmets have therefore adapted the configuration of the helmet as a standard model so that hearing protection can be attached to the helmet in that there is a slot or the like in the edge of the helmet on either side above the position of the ear. The hearing protection for the helmet is then provided with a helmet part that can be attached to the helmet in the slot, for example, by a snap fastener.
The hearing protection is worn during work in a protecting position or a working position, in which the caps of the hearing protection lie tightly against the user's head around the ears. Besides being worn in the working position, it should also be possible to move the caps into a resting position when the protection is not needed at the moment, e.g., during a work break. It is therefore desirable for the caps to be moved into a resting position without having to remove the hearing protection from the helmet. One such commonly occurring position of rest is taken up by rotating the ear caps backward and upward so that they are placed and remain outside of the helmet. In order for the caps to pass the edge of the helmet and take up the downward rotated position, it is often necessary to first move them into a tilted-out position just outside the ears. It is advantageous to move the ear caps into and maintain them in the tilted-out position, e.g., to make possible a short conversation while working.
Different helmet manufacturers use different slots or other elements to enable the fastening of the hearing protection to the helmet. It is therefore desirable for the hearing protection to have easily replaceable parts or adapters which fit the slots, etc., of the different helmet manufacturers. In this way, the very same hearing protection can be easily used for helmets of different brand.
2. Prior Art
FIG. 1 a-c and 2 show a previously known arrangement for fastening of a hearing protection to a helmet. FIG. 1 a is a front plan view of the known arrangement. FIGS. 1 b and c are side views, where FIG. 1 c shows the components of the arrangement taken apart. The known arrangement contains a helmet piece 1 and a compound cap holder piece 2.
As appears most clearly from FIG. 1 c, the cap holder piece 2 contains a rotary plate 3 with a radially projecting annular flange 31, a bistable element in the form of a two-tongued leaf spring 4, a cap holder bracket 5 and a hinged cover plate 6. The leaf spring 4 is fixed by one end in the rotary plate 3 and by its other end to the cap holder bracket 5. The cap holder bracket has two elongated slots for adjustable fixation of an ear cap (not shown). The two-tongued leaf spring 4 has a bistable configuration, so that the cap holder bracket 5 can be moved between and held in the tilted-in position as shown by FIG. 1 b and a position tilted out to the right (not shown).
The helmet piece 1 contains a receiving piece 11 and an elastic fixation tongue 12 projecting downward from the receiving piece. The fixation tongue 12 is configured to snap into a slot formed in a helmet (not shown). FIG. 2 shows a somewhat different helmet piece 1′ on a smaller scale. The helmet piece 1′ differs from the above described helmet piece 1 simply in that the fixation tongue 12′ has a different configuration to fit into a helmet whose slot has a different geometry. The receiving piece 11 of the helmet piece 1′ is identical to the receiving piece 11 shown in FIG. 1 a-c. The receiving piece 11 in both helmet pieces 1 and 1′ contains an elastically resilient tongue 13 with a forward projecting flange 17 shaped as a circular arc, an upper flange 14 of semicircular shape, arranged around the tongue 13 and projecting radially inward, a lower edge 15 shaped as a circular arc, and a first forward projecting stop piece 16.
The rotary plate 3 is held and able to rotate in the receiving piece 11 in that the annular flange 31 of the rotary plate is inserted beneath the radially inward projecting flange 14 of the receiving piece. The projecting flange 17 of the resilient tongue 13 thus engages with the radially inward pointing cylindrical surface on the annular flange 31. The elasticity of the resilient tongue 13 allows the annular flange of the rotary plate 3 to engage and disengage from this rotational fastening by a snap action. The rotary plate 3 is inserted into and removed from the receiving piece 1 by a relative displacement in the vertical direction.
FIGS. 1 a and 1 b show the cap holder piece 2 in the working position. In this position, the two-tongued leaf spring 4 has taken up its position tilted in to the left in FIG. 1 b and the rotary plate 3 has taken up a rotational position relative to the receiving piece 11, in which the cap holder bracket 5 is directed downward. In order to move the cap holder bracket 5 into a resting position arranged outside the helmet, one first presses the cap holder bracket to the right in FIG. 1 b, whereupon the leaf spring 4 assumes its tilted out position. After this, one turns the rotary plate 3 about 100 degrees counterclockwise per FIG. 1 a, relative to the receiving piece 11. In this rotational position, a second stop piece 32 formed on the annular flange 31 is caused to engage with the first stop piece 16 of the receiving piece, projecting in the direction of the rotary plate. The purpose of this engagement is to hold the cap holder piece in the resting position with a hearing protection mounted in place.
One problem with the above described known arrangement, however, is an inability to maintain the cap holder piece in the resting position. The force of gravity acting on the hearing protection and the lever arm, defined by the distance between the hearing protection and the axis of rotation of the rotary plate, produces a torque which strives to disengage the first and second stop from each other. Studies have shown that the hearing protection can be subjected to forces amounting to around 5-8 G, for example, when the user is walking on a stairway. The two stops can then become disengaged from each other, whereupon the cap holder piece with the hearing protection rotates downward from its resting position. This is often perceived as an annoyance by the user. To prevent such a downward rotation, the user might tilt in the cap holder piece in the upward rotated resting position so that the bistable leaf spring presses the hearing protection against the helmet shell. This results in relatively large forces, for example, at the fastening of the helmet piece in the helmet, which are liable to damage the helmet and/or the helmet piece of the arrangement.
Protective helmets can be made from ABS, for example. More recently, PE has also come to be used for manufacture of protective helmets. Due to the lower shape stability of PE, some of the problems connected with the above described known arrangement are even more serious when using protective helmets made of PE.

SUMMARY OF THE INVENTION

One purpose of the present invention is therefore to provide an improved arrangement for fastening of a hearing protection to a helmet.
Another purpose is to provide an arrangement which leads to a more secure retention of the hearing protection in a resting position rotated upward outside the helmet.
Furthermore, one purpose is to provide an arrangement which reduces the risk of damage to the helmet and the arrangement.
Yet another purpose is to provide an arrangement which reduces the problems arising when used on helmets made from PE.
One further purpose is to provide an arrangement which is reliable, durable, and easy to use.
A further purpose is to provide an arrangement comprising a limited number of constituent parts, and which is relatively simple and cheap to make.
These and other purposes are achieved with an arrangement of the kind indicated in the preamble of patent claim 1, which arrangement has the special technical features indicated in the characterizing passage of the claim.
The invention is based on the insight that the above described problem with swinging down from the resting position in the previously known arrangement is caused by the resilient tongue giving way and bending in toward the helmet when the first and second stops are pressed together if the cap holder piece in the resting position is subjected to a force which strives to turn the cap holder piece into the working position. Since the stops are pressed together during the turning, the rotary plate is twisted about a horizontal axis which is perpendicular to the axis of rotation of the rotary plate. In this process, the lower part of the rotary plate with the second stop piece is pressed in the outward direction, from the first stop piece on the receiving piece, and the upper part of the rotary plate diametrically opposite the second stop is pressed inward toward the resilient tongue. Due to the elasticity of the tongue, it allows this twisting or slanting of the rotary plate to occur, whereupon the second stop loses its engagement with the first stop and can move past it. Yet the resilient tongue has to have a certain elasticity in order to let the rotary plate of the cap holder piece snap in place and be released from the receiving piece of the helmet piece.
According to the invention, this problem is solved with a projection protruding from the receiving piece essentially parallel to the axis of rotation. The projection is arranged on the receiving piece so that, at least in the resting position, it limits or prevents the movement of the rotary plate inward towards the resilient tongue by bearing against some portion of the cap holder piece. In this way, the slanting or twisting about a horizontal axis which is perpendicular to the axis of rotation of the rotary plate is limited or prevented in the resting position. The second stop is thus not able to become disengaged from the first stop, unless a relatively large torque is applied to the cap holder piece in the direction towards the working position.
The projection is conveniently arranged so that in the resting position it prevents a slanting of the rotary plate by thrusting against the bistable element projecting from the rotary plate. In this way, the projection can be placed radially outside the rotary plate, so that the rotary motion of the rotary plate about the axis of rotation is not prevented.
The rotary plate advisedly will have a third stop piece which, engaging with the first stop piece on the receiving piece, defines a second resting position which is reached by turning in the opposite direction as compared to the first resting position. The arrangement will then have a second projection to prevent slanting of the rotary plate in the second resting position. The arrangement can then be used on both sides of the helmet and at the same time allow the cap holder piece to take up a stable backward-turned resting position in either case, by clockwise or counterclockwise rotation, respectively. In such a case, the second projection is also advisedly arranged so as to prevent a slanting of the rotary plate by thrusting against the bistable element.
The first and second projection can either be formed as separate elements or as a continuous projection. In this way, one has freedom of choice in the configuration which is most suitable in terms of manufacturing technology, strength, esthetic or other reasons.
The rotary plate is advisedly secured releasably in the receiving piece by snap action under the influence of the resilient tongue. This allows for a simple replacement of the helmet piece so that the very same cap holder piece can be used for helmets with different types and shapes of fasteners for the hearing protection by varying the helmet piece.
The means of attachment of the helmet piece to a helmet advisedly include at least one flexible male part for separable snap fastening to a corresponding female part on the helmet. In this way, a simple fastening and removal of the arrangement from the helmet is made possible, which means that the very same arrangement can be used for different helmets.
The invention also involves a helmet containing such an arrangement.
Further properties and advantages of the arrangement and the helmet according to the invention shall appear from the following detailed description and the patent claims.

BRIEF DESCRIPTION OF DRAWINGS

The following provides a detailed description of sample embodiments with regard to the drawings, where:
FIG. 1 a-c is a front plan view, a side view and an exploded view of a cap holder arrangement according to the prior art.
FIG. 2 is a front plan view of a part making up a prior known arrangement.
FIG. 3 is a front plan view of a configuration of the arrangement according to the invention, showing the arrangement in a working position.
FIG. 4 a-c shows a helmet piece making up the arrangement shown in FIG. 3, where FIG. 4 a is a front plan view, FIG. 4 b is a rear plan view, FIG. 4 c is a side view and FIG. 4 d is a section along line A-A of FIG. 4 a.
FIG. 5 is a front plan view showing a part of the helmet piece of FIG. 4 a on magnified scale.
FIG. 6 is a partially transparent front plan view of the arrangement shown in FIG. 3, showing the arrangement in the resting position.
FIG. 7 is a cross section along line B-B of FIG. 6 with some parts removed.

DETAILED DESCRIPTION OF EMBODIMENTS

The following describes two sample embodiments of the invention with regard to FIGS. 3-7. In these drawings, the embodiment shown in FIG. 6 differs from the embodiment shown in FIG. 3-5 and 7 merely in that the helmet piece of the arrangement is shaped differently in order to fit different helmets whose slots for attachment of the hearing protection have a different geometrical configuration.
The arrangements according to the invention, shown in FIG. 3-7, like the known arrangement shown in FIG. 1 a-c, contain a helmet piece 101 and a cap holder piece 102.
FIG. 4 a-c shows only the helmet piece 101 for a first embodiment of the invention. FIG. 5 shows on magnified scale only a receiving piece 111 of the helmet piece 101.
The helmet piece 101 contains a receiving piece 111 and an elastic fixation tongue 112, projecting downward from the receiving piece. The fixation tongue 112 is configured as a male part and it contains two outer tongue pieces 112 a, 112 b and a central flexible tongue piece 112 c with a snap hook for fastening to a corresponding female part in the form of a fixation slot which is arranged in the helmet.
The receiving piece 111 of the helmet piece contains an elastically resilient tongue 113 with a circular-arc flange 117 projecting forward (to the left in FIG. 4 d). The receiving piece 111 also contains a semicircular flange 114, projecting radially inward and arranged around the tongue 113, a lower circular-arc edge 115, and a first stop piece 116 projecting forward. Furthermore, the helmet piece 101 according to the invention contains a first 118 and a second 119 projection, extending forward (to the left in FIGS. 4 c and 4 d). The projection 118, 119 is formed as a single piece with the receiving piece 111 and is placed partly on and radially outside of the semicircular flange 114 of the receiving piece, which projects radially inward.
In the embodiment shown in FIG. 6, the helmet piece 101 contains a receiving piece 111 identical to the above described receiving piece with a somewhat modified fixation tongue 112′.
Referring in particular to FIGS. 3 and 7, the cap holder piece 102 of the arrangement contains a rotary plate 103 with a radially projecting annular flange 131. The cap holder piece also contains a cap holder element in the form of a cap holder bracket 105 for fastening a hearing protection (not shown) and a hinged cover plate 6. Like the known arrangement shown in FIG. 1 c, the cap holder piece also contains a bistable element in the form of a two-tongued leaf spring 104 (see FIG. 7). The leaf spring 104 is fixed by its one end in the rotary plate 103 and by its other end to the cap holder bracket 105. The two-tongued leaf spring 104 has a bistable configuration, so that the cap holder bracket 105 can be moved between and held in a position tilted in against the ear and a position tilted out away from the ear.
As is shown most clearly by FIG. 7, the rotary plate 103 is fastened and can rotate in the receiving piece 111 in that the annular flange 131 of the rotary plate is inserted beneath the radially inwardly projecting flange 114 of the receiving piece. The projecting flange 117 of the resilient tongue 113 is then engaged with the radially inwardly turned cylindrical surface on the annular flange 131. The elasticity of the resilient tongue 113 allows the annular flange 131 of the rotary plate 103 to be engaged by and disengaged from this fastening by snap action. The rotary plate 103 is inserted into the receiving piece 111 by pressing the rotary plate upward when the receiving piece is in the position shown in FIG. 3.
FIG. 3 shows the cap holder piece 102 in the working position. In this position, the two-tongued leaf spring 104 has taken up its position tilted in against the ear and the rotary plate 103 has taken up a rotational position relative to the receiving piece 111, in which the cap holder bracket 105 is directed downward. In order to move the cap holder bracket 105 into the resting position situated outside of the helmet, the cap holder bracket is first pressed outward from the ear, whereupon the leaf spring 104 takes up its tilted out position. After this, the rotary plate 103 is turned about 100 degrees clockwise per FIG. 3, relative to the receiving piece 11, and it takes up the rotational position shown in FIG. 6. FIG. 7 also shows this resting position, and it can also be seen here how the bistable spring 104 has taken up its tilted out position. In this resting position, a second stop 132 configured on the annular flange 131 is brought into engagement with the first stop 116 of the receiving piece 111, projecting forward in the direction of the rotary plate 103.
As is clearly shown in FIG. 7, the leaf spring 104 in the resting position is just beyond the projection 119, at only a slight distance from it. If the lower part of the rotary plate 103 in FIG. 7 and the annular flange 131 are pressed to the left in the direction of the resilient tongue 113, the leaf spring 104 will make contact with the projection 119 and thereby prevent further movement to the left. Hence, a relatively large torque on the rotary plate in the direction of the working position (counterclockwise in FIG. 6) is needed to make the second stop 132 pass by the first stop 116 so that these stops are disengaged from each other and the cap holder piece can return to the working position. Thanks to the relatively large force required to disengage the two stops 132 and 116 from each other, the cap holder piece 102 is prevented from unintentionally dropping down from its position of rest away from the helmet, for example, when the user is walking on stairs, or during some other motion where large accelerations and decelerations act on the hearing protection and the cap holder piece. Thus, the user does not need to try to prevent such unintentional swinging down of the cap holder piece by tilting the cap holder bracket in the resting position so that the hearing protection is pressed against the helmet shell. This also avoids the damage to the helmet and the helmet piece which might otherwise occur if the bistable leaf spring in the resting position happens to press the hearing protection against the helmet shell.
It should be noted that the projection 119 prevents a slanting of the rotary plate 103 only when the leaf spring 104 is placed in front of the projection and the cap holder piece thus rotates to the resting position. When the cap holder piece is in the working position, for example, or some other rotational position, the projection 119 does not affect the movement of the rotary plate. It is therefore possible, for example when the rotary plate is in the rotational position corresponding to the working position, to fasten or remove the rotary plate and the cap holder piece from the receiving piece and the helmet piece, thanks to the elasticity of the resilient tongue.
As shown by FIG. 3-6, yet another projection 118 is arranged on the receiving piece 111 of the helmet piece 101. This projection has the same configuration and function as the projection 119 and it ensures that the cap holder piece is held in another resting position (not shown), in which the cap holder piece has rotated about 100 degrees counterclockwise from the working position shown in FIG. 3. For the same reason, the arrangement is also provided with a third stop (not shown), which is arranged on the rotary plate and which has a position and a configuration corresponding to the second stop.
Two sample embodiments of the invention have been described above. However, it is clear that the invention is not limited to the above-described embodiments, but rather it can be varied freely within the framework of the following patent claims. For example, the means of fastening the arrangement to a helmet which are arranged on the helmet piece can take on a number of different forms in order to fit different helmets on the market. The cap holder piece, of course, can also be variously shaped or replaced by different cap holder elements in order to fit different hearing protection devices occurring on the market.

Claims

1. Arrangement for securing a hearing protector to a helmet, which arrangement comprises a cap holder piece (102) and a helmet piece (101), wherein

the cap holder piece contains a rotary plate (103), a bistable element (104) and a cap holder element (105), which is secured by means of the bistable element to the rotary plate to allow a hearing protection, secured to the cap holder element, to take up a tilted out and a tilted in position relative to the rotary plate, and

the helmet piece comprises means (112, 112′) for the attachment to a helmet and a receiving piece (111), in which the rotary plate is secured, pivotal about an axis of rotation, which receiving piece includes a tongue (113) which is resilient in a direction essentially parallel to the axis of rotation and a first stop piece (116) which, under the action of the resilient tongue and in cooperation with a second stop piece (132) arranged on the rotary plate, releasably maintains the rotary plate in a first rotational position relative to the receiving piece, characterized by

a first projection (119) extending from the receiving piece essentially parallel to the axis of rotation, which in the first rotational position limits the motion of the rotary plate toward the resilient tongue by bearing against the cap holder piece.

2. Arrangement according to claim 1, wherein the first projection (119) is arranged so that in the first rotational position it limits the motion of the rotary plate (103) by bearing against the bistable element (104).

3. Arrangement according to claim 1, containing a third stop piece arranged on the rotary plate (103) which, under the action of the resilient tongue (113) and engaging with the first stop piece (116), releasably maintains the rotary plate in a second rotational position relative to the receiving piece, wherein the arrangement contains a second projection (118) which, in the second rotational position, limits the motion of the rotary plate toward the resilient tongue by bearing against the cap holder piece.

4. Arrangement according to claim 3, wherein the second projection (118) is arranged so as to limit the motion of the rotary plate by bearing against the bistable element in the second rotational position.

5. Arrangement according to claim 3, wherein the first and second projection are formed as a continuous projection.

6. Arrangement according to claim 1, wherein the rotary plate (103) is secured releasably in the receiving piece (111) by snap action under the influence of the resilient tongue (113).

7. Arrangement according to claim 1, wherein the means for attachment of the helmet piece to a helmet include at least one flexible male part (112 c) for separable snap fastening to a corresponding female part on the helmet.

8. Arrangement according to claim 1, further including a helmet.