Patent Description:
Backrests for scuba divers, that is, back support elements for one or more air cylinders for scuba diving, have been present on the market for some time in an extreme variety of shapes and sizes, both in a simple configuration and in a configuration integrated into a buoyancy control device (BCD), and are constrained to the scuba diver's body in various ways, generally with flexible straps.

It is well known that a plurality of straps and a corresponding plurality of connections and closures are generally interpreted by a scuba diver as an annoyance during donning, and even more so during doffing, which, under emergency conditions, may need to be simple and rapid.

As is known, there are backrests for scuba divers on the market that are provided with a single strap for constraining them to the diver's body and in which the strap, in a first upper part thereof, acts as a support for the weight of the cylinder(s) on the diver's shoulders and, in a second part thereof, suitably routed, allows a coupling of the two ends in an abdominal position.

Patent application <CIT> of the same Applicant discloses a backrest for a scuba diver in which the release of the single strap constraining in the abdominal position maintains the constraint of the backrest on the diver's shoulders.

<CIT> discloses an apparatus for carrying a tank of compressed breathing gas on the back of a user having a main back plate molded portion with handle openings and webs therein, and slits for receiving shoulder straps. The shoulder straps are looped through the back plate slits and webs in a continuous manner to form a combination shoulder, chest, and waist strap interconnected by means of two quick release fittings.

However, such backrests for scuba divers of a known type, provided with a single strap for constraining them to the diver's body, imply that in the event that is necessary to adjust only the constraint on the shoulders the diver must proceed to tighten or loosen the constraint in the abdominal position, with evident inconvenience.

There are also known straps for the constraint on the diver's shoulders made with elements separate from the strap and/or straps in the abdominal position and connected to the latter by means of reciprocal adjustable connections: connections of this type, typically made of plastic materials, generally prove to be cumbersome and invasive for the diver, in particular in cave diving, where for safety reasons all the elements and accessories worn must be able to ensure utmost reliability against impacts with and entrapments between rocks or protrusions of any kind.

A need is thus felt to improve the structure of the known backrests for scuba diving.

The technical task of the present invention, therefore, is to provide a backrest for a scuba diver that enables the aforementioned technical drawbacks of the prior art to be eliminated.

Within the scope of this technical task, one object of the invention is to provide a backrest for scuba divers provided with a single constraining strap that enables the constraints on the shoulders to be adjusted without acting on the constraint in the abdominal position.

Another object of the invention is to provide a backrest for scuba divers provided with a single constraining strap that has adjustment elements which are not cumbersome.

Yet a further object of the invention is to provide a backrest for scuba divers provided with a single constraining strap which enables a simple, effective and reversible adjustment of the constraints on the shoulders.

The technical task, as well as these and other objects, are achieved according to the present invention by providing a backrest for a scuba diver as defined in Claim <NUM>.

In one embodiment, each adjustment block has a bottom, two lateral walls, and a separating partition between said first pin and said second pin.

In one embodiment, the handgrip element is parallel to said bottom and the clamp element extends from said handgrip element in an angled direction in the direction of said second pin.

In one embodiment, the actuation of said clamp element between a position of blocking and a position of unblocking the sliding of said end of said lower portion of said strap around said second pin is configured as a rotation of said block around said first pin.

Other features of the present invention are defined, moreover, in the subsequent claims.

Additional features and advantages of the invention will become more apparent from the description of a first preferred but not exclusive embodiment of the backrest for a scuba diver according to the invention, illustrated by way of non-limiting example in the appended drawings, in which:.

The aspects of the present description, as generally described in the present context and illustrated in the figures, may be arranged, replaced, combined and designed in a wide variety of different configurations, as defined in the appended claims.

With reference to the above-mentioned figures, they show a backrest for a scuba diver denoted in its entirety by the reference number <NUM>.

The backrest is typically symmetrical with respect to a vertical axis Y; in the figures, similar reference numbers typically identify similar components, unless the context indicates otherwise. The backrest for a scuba diver <NUM> comprises a shaped plate <NUM> for supporting at least one air cylinder, not shown in the figures.

The shaped plate <NUM> comprises at least one lower right slide-through element <NUM> and a lower left slide-through element <NUM>; a strap <NUM> is fixed to the shaped plate <NUM> and slides through the slide-through elements <NUM>.

The strap <NUM> comprises at least one upper right portion 3A configured to fit around the scuba diver's right shoulder and symmetrically an upper left portion 3A configured to fit around the scuba diver's left shoulder; the strap <NUM> comprises a lower portion 3B configured to fit around the scuba diver's abdomen.

Advantageously, according to the present invention, the backrest <NUM> comprises a right adjustment block <NUM> between the upper right portion 3A and the lower portion 3B of the strap <NUM>; symmetrically, the backrest <NUM> comprises a left adjustment block <NUM> between the upper left portion 3A and the lower portion 3B of the strap <NUM>.

Each adjustment block <NUM> has a width L that is greater than the width of the lower portion 3B of the strap <NUM> and a height H in the direction of the longitudinal axis of the lower portion 3B.

Each of the adjustment blocks <NUM>, the right one and the left one, has a first pin <NUM> engaged in a first loop <NUM> of one end of the corresponding upper portion 3A of the strap <NUM>, and a second pin <NUM> engaged in a second loop <NUM> of a corresponding end of the lower portion 3B of the strap <NUM>.

The end of the upper portion 3A is blocked from sliding over the first pin <NUM> by an adjustable blocking means <NUM>. As an alternative to the adjustable blocking means <NUM>, a stitched seam can be provided between the ends of the first loop <NUM>, whereby the end of the upper portion 3A is blocked from sliding over the first pin <NUM>.

Conveniently, each adjustment block <NUM> has at least one clamp element <NUM> for clamping the lower portion 3B of said strap <NUM> to block the sliding of the end of the lower portion 3B of the strap <NUM> around the second pin <NUM>.

Advantageously, each adjustment block <NUM> has at least one handgrip element <NUM> for actuating the clamp element <NUM> between a position of blocking and a position of unblocking the sliding of the end of the lower portion 3B of the strap <NUM> around the second pin <NUM>.

Each adjustment block <NUM> is made up of a body having a bottom <NUM> and two opposing lateral walls <NUM>, <NUM> that delimit the adjustment block <NUM> in the width L.

The bottom <NUM> and the lateral walls <NUM>, <NUM> delimit a cavity of the body of the adjustment block <NUM>. The first pin <NUM> and the second pin <NUM> extend parallel in said cavity in the direction of the width L between the two lateral walls <NUM>, <NUM>.

Also positioned in that cavity there is a separating partition <NUM> between the first pin <NUM> and the second pin <NUM>.

The separating partition extends transversely from the bottom <NUM>.

The handgrip element <NUM> is made up of a shaped edge of the bottom <NUM> that extends in the direction of the width L and delimits an opening <NUM> for the introduction of the diver's fingers in the cavity of the body of the block <NUM> for the actuation of the clamp element <NUM>.

The handgrip element <NUM> and the first pin <NUM> extend along opposite edges of the bottom <NUM> that delimit the adjustment block <NUM> in the width L.

The clamp element <NUM> extends in the cavity of the body of the block <NUM> from the handgrip element <NUM> in an angled direction in the direction of the second pin <NUM>.

The bottom <NUM> has, on one side of the separating partition <NUM>, a first slot <NUM> that extends in the direction of the width L for the passage of the first loop <NUM> wrapped around the first pin <NUM> and, on the other side of the separating partition <NUM>, a second slot <NUM> and a third slot <NUM> that extend in the direction of the width L and are interposed between the separating partition <NUM> and the clamp element <NUM> for the passage of the second loop <NUM> wrapped around the second pin <NUM>.

Conveniently, both the first pin <NUM> and the second pin <NUM> have at least one or more protuberances 60i, 80i for engaging, in a blocked position, with the first loop <NUM> of the upper left portion and with the second loop <NUM> of the lower portion 3B of the strap <NUM>, respectively.

According to the invention, the adjustment block <NUM> is a monolithic piece, for instance but not necessarily made of thermoplastic polymeric resins.

From an operational viewpoint, the actuation of the clamp element <NUM> between a position of blocking and a position of unblocking the sliding of the end of the lower portion 3B of the strap <NUM> around the second pin <NUM> is configured as a rotation of the block <NUM> around the first pin <NUM>.

The operation of a backrest for a scuba diver according to the invention appears clear from what is described and illustrated and, in particular, is substantially the following.

The diver puts on the backrest <NUM>, fitting the upper portions <NUM> A of the strap <NUM> around his shoulders and the portion 3B in the abdominal position; by adjusting the portion 3B by sliding it through the lower slide-through elements <NUM> he secures the backrest in a first position, the dorsal position.

As illustrated in <FIG>, the first loop <NUM> of the end of the upper portion <NUM> A of the strap <NUM> is engaged in the first pin <NUM> of the block <NUM> and is blocked from sliding by the blocking means <NUM>.

The adjustment block <NUM> is in the blocking position: the second loop <NUM> of the end of the lower portion 3B of the strap <NUM> is engaged in the second pin <NUM> of the block <NUM> and is blocked from sliding by the clamp element <NUM> in the blocking position that counters the tension F1 on the lower portion of the strap 3B.

As illustrated in <FIG>, for any adjustment of the strap <NUM> at the opposite ends of the lower portion of strap 3B, the diver will move the adjustment block <NUM> into the unblocking position.

The diver will act on the handgrip <NUM> and rotate the block <NUM> around the first pin <NUM>; during the rotation, the clamp element <NUM> will be parallel to the lower portion of the strap 3B engaged around the second pin <NUM>, and enable the consequent sliding thereof at a tension F2.

Once the adjustment has been obtained, the diver, by acting on the handgrip <NUM> in a rotation opposite the unblocking one, will bring the clamp element <NUM> back to the forced engagement of the lower portion of strap 3B against the second pin <NUM>, and hence the adjustment block <NUM> into the blocking position at the desired length of constraint of the strap <NUM> around his body.

It has in practice been ascertained that a backrest for a scuba diver provided with a single constraining strap according to the invention is particularly advantageous, as it enables the constraints on the shoulders to be adjusted without having to intervene on the constraint in the abdominal position.

Another advantage of the invention is that of providing a backrest for a scuba diver provided with a single constraining strap having adjustment elements that are not cumbersome.

Yet a further advantage of the invention is that of providing a backrest for a scuba diver provided with a single constraining strap which enables a simple, effective and reversible adjustment of the constraints on the shoulders.

Claim 1:
A backrest for a scuba diver (<NUM>) comprising a shaped plate (<NUM>) for supporting at least one air cylinder, said shaped plate (<NUM>) comprising at least one lower right slide-through element (<NUM>) and at least one lower left slide-through element (<NUM>); a left strap (<NUM>) and a right strap (<NUM>) fixed at the top to said shaped plate (<NUM>) and slidable through said slide-through elements (<NUM>), comprising an upper right portion (3A) configured to fit around the scuba diver's right shoulder, an upper left portion (3A) configured to fit around the scuba diver's left shoulder and a lower left portion (3B) and lower right portion (3B) configured to fit around the scuba diver's abdomen, wherein said left strap (<NUM>) and right strap (<NUM>) comprise a right adjustment block (<NUM>) between said upper right portion (3A) and said right lower portion (3B), and a left adjustment block (<NUM>) between said upper left portion (3A) and said left lower portion (3B), wherein each adjustment block (<NUM>) is a monolithic piece, has a first pin (<NUM>) engaged in a first loop (<NUM>) of one end of said upper portion (3A) of said strap (<NUM>), a second pin (<NUM>) engaged in a second loop (<NUM>) of one end of said lower portion (3B) of said strap (<NUM>), a clamp element (<NUM>) for clamping said lower portion (3B) of said strap (<NUM>) to block the sliding of said end of said lower portion (3B) of said strap (<NUM>) around said second pin (<NUM>), and a handgrip element (<NUM>) for actuating said clamp element (<NUM>) between a position of blocking and a position of unblocking the sliding of said end of said lower portion (3B) of said strap (<NUM>) around said second pin (<NUM>), characterised in that said first pin (<NUM>) and said second pin (<NUM>) respectively having at least one or more protuberances (60i, 80i) for engaging in a blocked position respectively with said first loop (<NUM>) of said upper left portion (3A) and with said second loop (<NUM>) of said lower portion (3B) of said strap (<NUM>), and in that said lower portion (3B) is slidable for adjustment through said slide-through element (<NUM>) to secure the backrest in a first position, the dorsal position .