SAFETY WRENCH AND A MATCHING NUT

Field of invention

The present invention relates to means for securing objects in a limited access area. The invention further relates to a safety wrench and a matching nut for securing objects, such as circular knife blades, in a cutting device where the access to the axis onto which the knife blade is secured is limited.

Background of the invention

Matching wrench and nut constructions are well known in the art.

A security bolt or nut design is disclosed in US 3,482,481. The head is frustro-conical with two sets of grooves. The grooves in each set are parallel and oblique to the generatrix of a cone.

One set of grooves slants to the right and the other to the left. The cooperating wrench has two ends, each with a frustro-conical socket having one set of ribs, wherein the set at one end corresponds to the right slanting grooves and the set at the other end corresponds to the left slanted grooves. One end of the wrench is used to tighten the bolt and the other to loosen it. The wrench and bolt head must be used as a combination and neither can accommodate or be accommodated by conventional hardware.

US6854365 discloses a wrench comprising two jaw members each having first and second gripping portions for gripping an item, such as a bolt to be rotated about a work axis in order to fasten or loosening an item. The wrench further comprises a leverage portion spaced from the gripping portion, a handle and an engagement mechanism on the handle for movement therewith for engagement with the leverage portion of the second jaw member.

A wrench to tighten or remove nuts and bolts in limited access areas is disclosed in US2005279192. The wrench comprises a socket with fluted interior walls cooperates with a handle assembly consisting of a head with complementary fluting on its exterior surface attached to one end of a shaft. The shaft is rotated as far as the available space permits in the limited access area. As the socket is placed over a nut or bolt and the head is inserted into the top of the socket the shaft can be rotated thereby causing the socket and the nut or bolt to be rotated with it and thereafter the head is lifted clear of the socket, returned to the starting position, and reinserted into the socket.

In order to attaching or tightening objects such rotating knife blades onto a rotating axis in a cutting device, such as a meat processing machines, a person sometimes needs to reach in to an limited access area of the device. This can be both difficult and dangerous in that it can be

difficult to hold the nut with one hand and the wrench with the other and yet access the axis onto which the blade is to be attached to.

Summary of the invention

It is an object of the present invention to provide a safety bolt or nut to secure objects such as knife blades to devices. It is further an object of the present invention to provide a matching wrench to tighten or loosening the safety nut in a limited access area. The wrench of the present invention is designed to have gripping means to grip and hold a safety nut securely, such that the operator can place such a nut onto an axis and tighten, without having to hold the nut with his/hers fingers. In the same manner the operator can stretch towards a fastened safety nut and secure the nut within the gripping portion of the wrench and loosen the nut. When the nut is detached from the axis it will not fall on the ground or within the device because it is held by the gripping and locking portion.

Description of the invention

In a first aspect of the present invention a fastening device is provided for safely securing an object. The fastening device comprises a wrench, further comprising two parallel members. The first member has a handle portion at one end and a jaw portion at the other end,. The second member is attached to the first member by a sliding means, whereby the second member can slide backwards and forward in the longitudinal direction of the first member. The second member has a sliding portion at one end and a locking portion at the other end. The fastening device further comprises a securing means for securing an object in a safe manner in a limited access area. The securing means comprises a mating section for mating with the jaw of the first member of the wrench and slot section for mating with the locking portion of the second member of the wrench. The securing means further comprises a support section for supporting the object to be secured and a guiding section for guiding the object to be fastened. Furthermore, the locking portion of the second member of the wrench fits into the slot section of the securing means.

In a second aspect of the present invention a method is provided for safely securing objects using the fastening device of the invention. The method comprises the steps of:

- locking the securing means to the wrench by sliding the second member forward into the slot section of the securing means, securing the object by bringing/tightening/ the securing means to the object using the wrench, unlocking the securing means from the wrench by sliding the second member backwards out of the slot section of the securing means, and

- un-attaching the securing means from the wrench.

Detailed description of the invention

According to the present invention a wrench is provided for use in limited access areas to tighten or remove corresponding safety nuts. According to the present invention, the term "securing means" refers to bolts or nuts, but more specifically safety bolts and safety nuts (hereinafter referred to as safety nuts).

In the present context the terms "sliding mechanism" and "sliding means" relate to a feature of the wrench of the present invention, where a second member of the wrench can slide backwards and forward in the longitudinal direction of the wrench. This mechanism is shown in a preferred embodiment as bolts of the second member penetrating two oval or longitudinal shaped openings in the first member, controlled by a knob of the second member connected to the first member of the wrench by a spring coil. Other more complex sliding mechanisms for two longitudinal members are also possible for the present invention.

A wrench according to the present invention in it's simplest form has a main member for rotating a safety nut with a handle portion on one end and an operating portion with a fixed jaw at the other end. The wrench further comprises a securing or a locking member including a movable jaw adapted to co-operate with the fixed jaw. The securing or locking member of the wrench is slidably disposed along the main member. The slidable securing or locking member may be operable from the handle portion of the wrench via a knob 11 or a protrusion which can be flicked or pushed by the operator using on finger. Therefore, the handle pivotally connected to the movable jaw f. ex. through a spring coil located at the joined portions. The locking or securing member is separated from the main member and connected via the sliding mechanism. The sliding mechanism only allows a certain longitudinal movement of the securing member in both directions.

The wrench comprises two parallel members, a wrench like member with a handle portion and a jaw portion and a locking member, which is attached to the wrench like member through a sliding mechanism. The jaw portion of the wrench like member has according to an embodiment of the present invention notch structures on the inner edge of the jaw. In this embodiment, the mating section of the securing means has grooves fitting into the notches of the jaw portion of the first member of the wrench. The locking member is attached to the wrench like via sliding means, such that the locking member can slide backwards and forward in the longitudinal direction of the wrench like member. The sliding portion of the locking member has a locking portion at the end corresponding to the jaw portion of the wrench like member to secure or lock the safety nut to the wrench.

The safety nut according to the present invention is a securing means for securing an object in a safely in a limited access area. The safety nut comprises four sections; i) a mating section; ii) a slot section; iii) a support section; and iv) a guiding section. The mating section of the safety

nut is adapted for mating with the jaw of the wrench like member of the wrench and has grooves fitting into the notches of the jaw portion of the wrench like member of the wrench. The slot section is adapted for mating with the locking portion of the locking member of the wrench. The support section is for supporting the object to be secured and the guiding section is adapted for guiding the safety nut into or up to the object to be fastened.

According to the present invention the method provided for safely securing objects relates to using the wrench of the invention for attaching the safety nut to the wrench. The mating section of the safety nut fits accurately into the jaw portion of the wrench like member and the mating the notch structures of the inner edge of the jaw to the grooves of the safety nut prevent the safety nut to slide out of the jaw portion if the wrench. The safety nut I then locked to the wrench by sliding the locking member forward into the slot section of the securing means. The object is next secured or fastened turning the safety nut around the axis onto which the object is to be attached to using the wrench to turn or rotate the safety nut. When the object is securely and safely fastened to the axis the safety nut is unlocked from the wrench by sliding the locking member backwards out of the slot section of the securing means and then the safety nut is un-attached from the wrench.

In an embodiment of the present invention the securing means is attached to the wrench by mating the notch structures of the inner edge of the jaw to the grooves of the securing means, In an embodiment of the present invention the locking and the unlocking of the securing means is controlled by a protrusion at the handle end of the sliding portion on the second member of the wrench.

The safety nut is provided in various sizes and thickness to be used to secure object of different size and shape in different settings. The different size of safety nuts is provided with a corresponding wrench adapted for mating with the various sections of the safety nut.

In an embodiment of the present invention the handle portion of the first member of the wrench comprises a stopping portion. This is provided so that when the operator is fastening or loosening and object, it will prevent the operator to slide forward as he/she is operating the wrench. This is a safety measure as the object to be secured might be a knife blade or the device onto which the object is being attached to is a hazardous device with moving or sharp parts.

In an embodiment of the present invention the locking portion of the second member of the wrench is a jaw portion. In this preferred embodiment, as shown in the drawings, the size of the jaw portion of the second member of the wrench has an opening and circumference corresponding to the slot section of the safety nut.

In an embodiment of the present invention the securing means further comprises a screw thread, but the securing means can operate through a lock-key fastening mechanism.

In an embodiment of the present invention the object to be fastened is a knife blade. The knife blade can be a circular knife blade adapted to be attached to an axis in a device such as. a cutting, sawing machine or any kind of separation device.

In an embodiment of the present invention the second member of the wrench further comprises a protrusion at the handle end of the sliding portion. Pulling force is then applied to the second member of the wrench by a spring coil. By applying force to the protrusion or releasing force of the spring coil the operator can control locking and unlocking of the nut from the wrench.

In an embodiment of the present invention the mating section of the securing means has a hexagonal shape and the slot section of the securing means is a recession between the mating section and the support section.

Therefore, the wrench of the present invention has the characteristic features of a traditional wrench with a handle portion and a jaw portion, which fits with a section of a bolt or a nut to be fastened or loosened. These mating portions are the functional features of the fastening means. The inner side of the jaw portion has protrusions or notches, which prevent the nut or the bolt to be secured from sliding back and forth in the jaw. The wrench also has a parallel longitudinal member, which can slide back and forth along the longitudinal length of the wrench. At the jaw end of the wrench, there is a locking portion, which is adapted to fit into a slot of the bolt or the nut to be secured. The functional feature of these mating parts of the invention is to prevent the bolt or the nut to fall sideways from the wrench and in fact the effect will be a locking effect as the nut can not slide out of the jaw in a longitudinal direction or sideways.

In the same manner the safety nut or bolt of the present invention is designed to have a mating portion to fit with the jaw portion of the wrench in order to perform the action of the nut. Therefore, the nut has grooves, which match the notches of the inner side of the jaw of the wrench. A slot section of the nut is adapted to mate with the locking portion of the wrench and thereby holding the nut securely in the wrench during operation. The support section of the nut or the bolt is then designed to support the object to be secured, forming another characteristic feature of the invention. At last a guiding section of the nut has the function of guiding the object to be secured in a functional position with the nut in order for the object to be securely fastened.

Detailed description of a preferred embodiment

The invention will now be described with respect to the following drawings and respective reference numbers.

FIG. 1 shows an application of the present invention, where a safety nut is used to secure a circular knife blade using the safety wrench.

FIG. 2 shows the wrench of the present invention.

FIG. 3 shows the wrench from two angles revealing the two parallel members of the wrench.

FIG. 4 shows a front and side views of the safety nut.

FIG. 1 discloses the fastening device of the present invention comprising a safety wrench 1 and a safety nut 2. In the embodiment shown in FIG. 1, a circular blade 3 is being secured by the fastening device of the invention. The figure shows the first member of the wrench 1, further comprising a handle portion 4 and a jaw portion 5. The circular blade is sitting on an axis (not shown) and the safety nut 2 is being rotated around the axis, either to fasten or loosen the safety nut 2.

The enlarged portion in FIG. 1 shows the mating parts of the fastening device. The jaw portion 5 of the wrench 1 mates with the mating section of the safety nut 2 and the notch structures 6 of the inner side of the jaw portion 5 fit snugly into the grooves 7 of the mating section of the safety nut 2. The enlarged figure further shows a screw thread 8 on the inner side of the safety nut 2.

FIG 2. discloses a wrench 1 according to an embodiment of the invention. In this embodiment, the handle portion 4 is formed in the first member 9 of the wrench 1 to favour gripping of the device and further comprising a stopping portion 10, which prevents the operator from sliding up and down the device while using it. The lower part of the handle portion 4 comprises a knob 11 or a protrusion which can be flicked, pushed or pushed by the operator using one finger to slide the second member 12 of the wrench 1 forward and backwards in order to lock or unlock the safety nut 2 from the wrench 1. In the embodiment shown in FIG. 2, the knob 11 is an extension of the second member 12 of the wrench 1 extending through an opening 13 in the middle portion of the first member 9. The knob 11 is operationally connected to the first member 9 by a spring coil 14, applying pulling force onto the second member 12 maintaining the second member 12 in a locking position. When the operator wants to secure a safety nut 2 to the wrench 1 or loosen it from the wrench 1, the operator pushes the knob 11 and then the second member 12 is pulled backwards into an unlocking position. Two openings 15 having an oval shape are positioned longitudinally in the part of the first member 9, between the spring coil 14 and the jaw portion 5, for attaching the second member 12 to the first member 9 of the wrench 1. A pin or a screw 16 is attached to the second member 12 penetrating each hole 15 and is able to slide forward and backwards, when the knob 11 is pushed or pulled. The locking portion 17 of the second member 12 of the wrench 1 is shown under the jaw portion 5 of the first member 9. The shape of the locking portion 17 is oval corresponding to the shape of its mating portion of the safety nut 2.

FIG. 3 discloses the two parallel members of the wrench 1 arranged side by side and connected via a sliding mechanism. The handle portion 4 of the first member 9 is shown as a flat member in this embodiment and the connection between the handle portion 4 and the jaw portion 5 is a

downward slanting stopping portion 10 with an opening 13 for the knob 11. FIG. 3 shows how the knob 11 of the second member 12 of the wrench 1 is connected to the first member 9 through the spring coil 14 by a bolt or a screw 18. The parallel position of the second member 12 shows the sliding portion 19 positioned under the first member 9 and a locking portion 17 at the jaw end of the first member 9. The sliding means connecting the second member 12 to the first member 9 is shown as two screws or bolts 16 penetrating the longitudinal (or oval) openings 15 in the middle and at the jaw end of the jaw portion 5. The longitudinal shape of the openings 15 allows the second member 12 to slide backwards and forward in the longitudinal direction of the first member 9. The pins/screws 16 penetrating the longitudinal openings of the handle portion 4 of the first member 9 are attached to the sliding portion 19 of the second member 12. The locking portion 17 of the second member 12 shown is FIG.3 is a jaw shaped portion 20 with a smaller jaw than the jaw portion 5 of the first member 9.

The figure shows the jaw portion 5 of the first member 9 form a different angle and notch structures 6 on the inner edge of the jaw. The notch structures 6 can be oval as shown in FIG. 1, but other structures are also possible such as triangular or square structures. The mating portion of the first and the second member 12 are different as their corresponding mating portions of the safety nut 2 have different shapes (see FIG. 4).

FIG. 4 discloses the securing means of the present invention. In the embodiment shown in FIG. 4, the securing means is divided into different sections formed in one piece of nut, bolt or the like. The four sections are from the out side to the inside:

i) a mating section 21 for mating with the jaw shaped portion 20 of the first member 9 of the wrench 1, ii) a slot section 22 for mating with the locking portion 17 of the second member 12 of the wrench 1, iii) a support section 23 for supporting the object to be secured, and iv) a guiding section 24 for guiding the object to be fastened.

The securing means further comprises a central opening penetrating the piece. In the embodiment shown in FIG. 4, the central opening of the securing means has a screw thread formation 8.

The mating section 21 of the securing means has a hexagonal shape and further comprises oval grooves 7 on the outer surface of the hexagonal shape. The grooves 7 are adapted to fit into the notches 6 of the jaw portion 5 of the first member 9 of the wrench 1. In the embodiment shown in FIG. 4 the locking portion 17 of the second member 12 of the wrench 1 fits into the slot section 22 of the securing means, which is formed as a recession in the nut or the bolt. The support section 23 is adapted to support the object to be fastened. In this embodiment a circular knife blade is to be secured on an axis, so the support section 23 has a larger circumference than the other section of the securing means to hold and support the knife blade. The guiding section 24 shown in FIG. 4 is adapted to fit into the central hole of the circular knife

blade. In an embodiment of the present invention, the circumference of the guiding section 24 is of a slightly less diameter than the central hole of the circular knife blade. Therefore, the guiding section 24 guides the knife blade tightly up against the support section 23 and secures the knife blade on the device.

The embodiment shown in the drawings are examples of the invention, but should not be limiting to other embodiments or designs of fastening means according to the present invention.