Patent Description:
Cutting device with a rotary blade, also known as rotary cutter, are widely used for cutting crafting materials, and especially cutting fabrics and papers. When the rotary blade become too dull, it is almost impossible to sharpen without a proper sharpener and therefore, needs to be replaced. For instance, <CIT> discloses a trim knife and means for attaching and securing a blade in a holder, and <CIT> discloses a rotary cutter with a grinder.

In the known solutions, replacing the blade requires the user to hold the blade between fingers. However, even a dull rotary blade can still be very sharp for skin tissue and cut the skin if not handled carefully.

It is thus an object of the present invention to provide a blade receiver assembly and a cutting device to minimalize the risk of accidentally cutting oneself. An object is particularly to introduce a solution by which one or more of the above identified problems of prior art and/or problems discussed or implied elsewhere in the description can be solved.

The invention is based on the idea of a rotary blade replacement system, which releases and attaches the rotary blade without the user needing to touch the blade at all. With this solution, one or more of the above-mentioned objects can be achieved.

One embodiment relates to a new blade receiver assembly comprising a switch, the switch comprising a switch cover and a switch base fixedly connected to each other, wherein the switch base has an opening. The blade receiver assembly further comprises an axle with a structural section and a body receiver section, wherein the axle is arranged to move through the opening of the switch base in relation to the switch.

Another embodiment relates to a cutting device comprising a body comprising a handle and a blade assembly holding member. The cutting device further comprises a rotary blade and the blade receiver assembly wherein the body receiver section is releasably connected to the blade assembly holding member.

Referring to <FIG>, which illustrates a hand-held cutting device. The cutting device comprises a body <NUM> comprising a handle <NUM> and a blade assembly holding member <NUM>. A rotary blade replacement assembly <NUM> is releasably connected to the blade assembly holding member <NUM>. The handle <NUM> may have a contoured form and grip portions to facilitate manual gripping of the cutting device. The blade assembly holding member <NUM> functions to provide a holding place for a rotary blade <NUM> when the rotary blade <NUM> and the rotary blade replacement assembly <NUM> are engaged with the blade assembly holding member <NUM>. The cutting device will be configured and dimensioned for rotary blades of various sizes and types. The rotary blade replacement assembly <NUM> can be mounted on either side of the body <NUM> for ambidexterity.

The cutting device may further comprise a slide member <NUM> connected to a slide base to move a blade guard <NUM>. The blade guard <NUM> gives an additional security for the user to prevent accidentally being cut by the rotary blade <NUM>.

The blade may be any rotary blade <NUM> with a perforated hole <NUM> in the middle. The blade may be a straight, wave, scallop, or pinking blade. The rotary blades are usually sold in a cartridge or a case, which may have more than one blade for a replacement. The package may hold two cartridges: one for dull blades and another for spare blades. The rotary blade <NUM> can be made of a ferromagnetic material, such as iron, steel, nickel, cobalt, etc..

<FIG> illustrates an exploded view of a blade replacement assembly <NUM> according to an embodiment. <FIG> illustrates a bottom view of a rotary blade replacement assembly <NUM>. <FIG> illustrates a cross-sectional view (dotted line of <FIG>) of the rotary blade replacement assembly <NUM>. The blade receiver assembly <NUM> comprises a switch <NUM>, wherein the switch <NUM> comprises a switch cover <NUM> and a switch base <NUM> which are fixedly connected to each other. The fixed connection may be realised by an adhesive or a mechanical fastener.

The switch cover <NUM> is designed for the user's fingers to hold onto, and forms an inner space with the switch base <NUM>. In the accompanying Figures, the switch cover <NUM> comprises a flip-up mechanism having a flippable arc <NUM>, wherein both ends of the arc <NUM> have an inner protrusion <NUM> facing each other and configured to fit and rotate inside a hole <NUM> of the switch cover <NUM>. The holes <NUM> are arranged on both sides of the switch cover <NUM>. During the use, the user may flip the arc <NUM> closer to the switch cover <NUM> which will improve line-of-sight to the rotary blade's <NUM> cutting edge by decreasing an overall height H of the blade replacement assembly <NUM>. During the blade replacement operation, the user may flip the arc <NUM> away from the switch cover <NUM> which will provide a better grip for the fingers. The arc <NUM> can have a smooth or angular curve.

The switch cover <NUM> may alternatively be designed as a protruded flange or a knob or any other practical and/or aesthetic design having an inner space. The switch base <NUM> can be designed as a plate to close the other side of the switch cover <NUM>. The inner space of the switch <NUM> is designed to hold at least partially an axle <NUM> within.

The switch base <NUM> has an opening <NUM> allowing the axle <NUM> to move through the opening <NUM>. The opening <NUM> can be shaped as oval, but other shapes are also applicable. The swich cover <NUM> and the switch base <NUM> may be manufactured of glass filled nylon or other suitable material comprising polymer. The axle <NUM> may be manufactured of steel material for its high durability.

The axle <NUM> comprises a structural section <NUM> and a body receiver section <NUM>, wherein the structural section <NUM> is provided at least partially within the switch <NUM>, and the body receiver section <NUM> is releasably connectable to a lock portion <NUM> in the blade assembly holding member <NUM>. The body receiver section <NUM> is dimensioned to pass through the perforation <NUM> of the rotary blade <NUM>. The body receiver section <NUM> of the axle <NUM> is arranged to be outside of the switch <NUM>, wherein the rotary blade <NUM> is arranged to fit and rotate between the body receiver section <NUM> and the switch base <NUM>.

A spring <NUM> is arranged inside the switch <NUM> and connected to the axle <NUM> allowing the axle <NUM> to move along an axis A against spring force or elastic deformation. The spring <NUM> in this context may refer to a coil spring or any other elastic material capable of storing mechanical energy, such as foam or rubber. The spring force prevents an end surface <NUM> of the axle <NUM> to move towards the switch cover <NUM> and contacting an inner surface <NUM> of the switch cover <NUM>.

The spring-loaded axle <NUM> further comprises a magnet <NUM> incorporated or embedded in the structural section <NUM> of the axle <NUM> by, for instance, adhesive, welding or mechanically. The magnet <NUM> may refer to any permanent magnet to produce a magnetic field, such as neodymium iron boron (NdFeB), samarium cobalt (SmCo), alnico and ceramic or ferrite magnets. The magnet <NUM> may be incorporated or embedded in the structural section of the axle <NUM> in such way that one surface <NUM> of the magnet <NUM> may be exposed from the opening <NUM> of the switch base <NUM>. The magnet <NUM> is arranged at a distance away from the axis A of the axle <NUM> and the surface <NUM> of the magnet <NUM> is at the same plane as the switch base <NUM> when the spring <NUM> is not in a compressed position. In some embodiments, two or more magnets <NUM> can be incorporated in the structural section <NUM> on both sides of the axis A to obtain stronger magnetic force.

In the embodiment illustrated in the <FIG>, the structural section <NUM> with the magnet <NUM> has bigger diameter than the body receiver section <NUM> so that the with the magnet <NUM> has bigger diameter than the body receiver section <NUM> so that the magnet is not obstructed by the body receiver section <NUM>. The spring <NUM> may be arranged partially inside the axle <NUM> to facilitate keeping the spring <NUM> in place. In another embodiment, the spring <NUM> may partially surround the axle <NUM>, wherein an end of the axle <NUM> closest to the switch is designed to fit inside the spring <NUM>.

The rotary blade <NUM> may be rotatably arranged on the axle <NUM> between the magnet <NUM> and the body receiver section <NUM>, wherein the magnetic force attracts and prevents the rotary blade <NUM> from sliding off the axle <NUM>. The magnetic force of the magnet <NUM> is also utilized during a rotary blade attachment operation. When the new rotary blade lies in the cartridge, the switch <NUM> with the axle <NUM> is moved closer so the body receiver section <NUM> passes through the perforation <NUM> of the rotary blade <NUM>, and with the magnetic force, the rotary blade <NUM> will be attracted to the magnet <NUM> without the user needing to touch the rotary blade <NUM> at all.

During the detachment operation of the rotary blade <NUM>, the axle <NUM> is arranged to slide in relation to the switch base <NUM> when the spring <NUM> of the spring-loaded axle <NUM> is compressed, wherein a distance between the magnet <NUM> and the rotary blade <NUM> increases and the magnetic force weakens causing the rotary blade <NUM> to slide off the axle <NUM>.

The swich <NUM> may be rotatable around the axis A of the axle <NUM>, or slidable along the axis A of the axle <NUM>, or both, when connecting to the blade assembly holding member <NUM> depending on the arrangement of the blade assembly holding member <NUM> and the body receiver section <NUM>. In the accompanying Figures, the body receiver section <NUM> is illustrated comprising a rotatable twist-lock mechanism <NUM> arranged to lock onto the lock portion <NUM> of the blade assembly holding member <NUM> in one position, and releasably slide in/out the blade assembly holding member <NUM> in another position. The term "twist-lock mechanism" in this context refers to a mechanism, whereby rotating an axle with at least one protrusion and/or depression to one direction will lock the axle to a counterpart, and by rotating the axle back or further, will unlock the axle from the counterpart. The twist-lock mechanism <NUM> may be grooves on the body receiver section <NUM>, which are arranged to connect and secure the axle <NUM> into the lock portion <NUM> in the blade assembly holding member <NUM> in a locked position. The axle <NUM> is released from the lock portion <NUM> by rotating the switch <NUM>. However, other known locking mechanisms may also be implemented.

The blade receiver assembly <NUM> may further comprise a bearing assembly <NUM>, wherein the switch base comprises a corresponding bearing assembly opening <NUM> for said bearing assembly <NUM>. The bearing assembly <NUM> may comprise a casing <NUM>, a ball bearing <NUM> and a bearing spring <NUM>, or any other known bearing solution. In the following Figures, the bearing assembly <NUM> is arranged in the bearing assembly opening <NUM> in such way that the ball bearing <NUM> partially protrudes from the switch case <NUM>. When the blade receiver assembly <NUM> is connected to the rotary blade <NUM> and the body <NUM>, the surface of the rotary blade <NUM> towards the switch <NUM> is in contact only with the ball bearing <NUM> due to the magnetic force, but the rotary blade <NUM> does not touch the switch base <NUM> or the magnet <NUM>. This allows friction between the switch <NUM> and the rotary blade <NUM> to be minimalized, which adds stability and smoothness for the user during the use. For a stable rotation of the blade <NUM>, preferably two bearing assemblies <NUM> are arranged on both sides of the axle <NUM> having a same distance from the axis A of the axle <NUM>.

The switch cover <NUM> may comprise a step <NUM> protruding from an inner surface of the switch cover <NUM> and supporting the spring <NUM>, wherein the spring <NUM> surrounds the step <NUM>, and allowing the axle <NUM> to slide along its axis A towards the step <NUM>, when the spring <NUM> of the spring-loaded axle <NUM> is compressed and supported by the inner surface of the switch cover <NUM>. In another embodiment, where the spring <NUM> partially surrounds the end of axle <NUM>, the switch cover <NUM> may comprise a cavity allowing the end of the axle to slide into the cavity while the inner surface <NUM> of the switch cover <NUM> supports the spring <NUM>.

The axle <NUM> may comprise a flange <NUM> at the structural section <NUM> to prevent the axle <NUM> from falling off the switch <NUM>. The flange <NUM> may be supported against an inner rim <NUM> of the opening <NUM> of the switch base <NUM>. Due to the spring force, the flange <NUM> contacts the inner rim <NUM> unless the switch <NUM> is pressed against the spring force, wherein the structural section <NUM> slides inside the inner space of the switch <NUM> and the flange <NUM> disconnects with the inner rim <NUM> of the switch base <NUM>.

The following is a suggestion how to replace a dull rotary blade with a new one using the above-described embodiment.

Claim 1:
A blade receiver assembly (<NUM>) for a rotary blade, comprising:
a switch (<NUM>) comprising a switch cover (<NUM>) and a switch base (<NUM>) fixedly connected to each other forming an inner space, wherein the switch base (<NUM>) comprises an opening (<NUM>);
an axle (<NUM>), having an axis (A), and comprising a structural section (<NUM>) and a body receiver section (<NUM>), wherein the structural section (<NUM>) is provided at least partially within the switch (<NUM>) and the body receiver section (<NUM>) is provided outside the switch (<NUM>);
a spring (<NUM>) provided inside the inner space of the switch (<NUM>);
wherein the axle (<NUM>) is movable against a spring force of the spring (<NUM>) through the opening (<NUM>) of the switch base (<NUM>) in relation to the switch (<NUM>),
characterized in that a magnet (<NUM>) is incorporated in the structural section (<NUM>) of the axle (<NUM>), wherein the magnet (<NUM>) is arranged at a distance away from the axis (A) of the axle (<NUM>), and a surface (<NUM>) of the magnet (<NUM>) is at a same plane as the switch base (<NUM>) when the spring (<NUM>) is not in a compressed position.