FR3137599A1 - Calibration rod for cutting and green spaces - Google Patents

Abstract

The invention allows calibration for cutting in all dimensions, from a few centimeters to several meters for any type of motorized or manual tool. The invention consists of a graduated flexible slat (2) equipped with rubber sights, an end sight (4) placed 50 centimeters from the cutting point and making it possible to obtain multiples by transfer as well as several intermediate sights placed at defined dimensions (25, 33 or 45 centimeters). The slat provides a reference for the position and orientation of the chain guide even when it is invisible when cutting large sections. The slat is fixed to the tool by a fixing bracket (1) comprising a pivot axis (5) and several position housings (13) allowing a folded (rest) and working position perpendicular to the guide (calibration). In the calibration position, the invention stabilizes the tool placed on sloping or uneven ground (crutch effect).

Description

Title of the invention: Calibration rod for cutting and green spaces

The present invention relates to a cutting calibration device for logging and green space management.

Currently, calibration is performed in three ways:

• A measuring tape with rough spray marking on a previously delimbed log.
• A rigid pin fixed by magnetism on the chain guide to calibrate the sections on delimbed logs with the risk of loss of the pin during contact with an obstacle or worse, the loss of the operator's balance or control of the tool.
• A template held by a second operator, generally facing each other. It is therefore subject to noise and olfactory nuisances as well as the risks of projections (splinters, chain oil) and the risks linked to the proximity of the cutting zone of the tool.

The device according to the invention allows the flow in calibrated sections of one or more dimensions of large sections (logs) such as branches and bundles previously tied up.

Indeed, a flexible plastic slat (2) positioned at 90° from the cutting axis allows, thanks to an end target and intermediate targets, a precise flow rate in several dimensions.

The position housing which holds the slat in the calibration position can unlock itself forwards or backwards in the event of sudden contact with an obstacle or when the operator loses balance, thus avoiding deviation uncontrolled use of the cutting tool and the inherent risks (very dense, uneven or steeply sloping area).

The slat can be folded down along the body of the tool and is held in position by one or more position housings, allowing the usual use of the tool.

Placement in the calibration position is carried out by grasping the first third of the slat with the right hand, which releases the operating trigger causing the cutting device to stop and rotate around the pivot point until ( x) position slot(s).

Likewise, the slat is folded down by grasping with the right hand and the reverse movement, from the calibration position housings to the rest position housings.

Implementation is therefore simple and secure.

The invention will be better understood on reading the description which follows, appended to the drawings illustrating the invention.

• There represents the exploded isometric view of the device. It includes the attachment bracket on the tool (1), the flexible plastic slat (2), the intermediate sights (3) and the end sight (4), the pivot axle bolt (5) which connects the fixing bracket (1) and the slat (2) through the holes (15). A rubber washer (6), the steel washer (8) and the nut (9) keep it in position. The rounded head screw (7) serves as a stop in the chamfered position housings (13) on the underside. The angular stop hole (10) allows the screw (11) to block the slat to prevent involuntary contact between the slat and the cutting zone. The holes (14) for passing the guide housing screws block the fixing bracket.
• There represents, in isometric view with view of the underside the fixing bracket with a double chamfered position housing (13). The housing holes are opposite the holes (16) accommodating the rounded head screws (7). The nut (12) holds the screw (10) in position. The axle holes (15) are repeated.
• There corresponds to the isometric view with top view for the two position housing system.
• There corresponds to the same view as the with a single position slot on the plastic slat.
• There corresponds to the isometric view with top view for the single position slot system.
• There corresponds to the front view which makes it possible to describe the operation of the pivot mechanism and to explain the interest of the rounded head screw (7) serving as a stop in the position housing.
• There describes a second principle of pivot mechanism using a compression spring (17) to facilitate disengagement of the pivot pin.
• There allows you to visualize the correspondence of the holes of the fixing bracket and the plastic fixing slat in the two positions (rest or calibration) in the case with double position housings.
• There corresponds to the in the case of a single position housing.
• There corresponds to the device integrated into a chainsaw in the rest position and seen from above.
• There corresponds to the device integrated into a chainsaw in the rest position and in left view making it possible to explain the positioning of the slat in relation to the guide (see dotted lines).
• There corresponds to the device integrated into a chainsaw in the calibration position and in top view with the safety handle hidden to explain the positioning of the fixing bracket in relation to the felling claw (competition point must be between the dotted lines) .
• There corresponds to an example of use for calibration with end staff.
• There corresponds to an example of use for calibration with intermediate target.
• There corresponds to an example of use, in isometric view, for superficial marking of the log for measurement transfer for calibration to define the thickness width of the staff for precise transfer. This must fit into the cutting slot (width of the cutting area of the tool).
• There corresponds to the same example of use in front view.
• There corresponds to an example of use by transfer for cutting with end target.
• There corresponds to an example of use by transfer for cutting with end target and graduation for a cut at 72 cm with a transfer at 50cm (end target (4) as reference) and a measurement at the graduation at 22 cm.
• There corresponds to the (simplified) representation of the slat graduation.
• There corresponds to the figure for the abstract and is identical to the .

The calibration device consists of three main elements: the mounting bracket on the tool (1), the soft plastic slat (2) and the pivot mechanism.

The first two elements are connected together by a pivot mechanism through the axle holes (15) allowing passage from the rest position (slat folded down along the body of the tool) to the calibration position (slat at 90° from the cutting axis) and vice versa as shown in Figures 10 and 12.

The mass of the complete device varies between 50 and 150 grams depending on the tool equipped.

Indeed, the larger the tool is, the larger the tool and the larger the diameter, the thicker and wider the slat and the larger the diameter of the pivot pin.

Firstly, this is explained by the fact that the increased rigidity allows a squareness mark (the wood offers directive marks on the surface) when the chain guide is made invisible when cutting logs with a diameter greater than the length of said guide such as presented in the the main reference being given by the chosen target.

Secondly, the rigidity allows the crutch effect obtained in the calibration position which ensures the stability of the tool when it is placed on the ground on steep terrain.

Two concrete examples:

• A 3.5 kg pruner will be equipped with a Ø6 mm steel pivot pin, a 4-5 mm thick slat for a width of 15 mm. Total mass of approximately 50 g.
• An 8 kg chainsaw will be equipped with a Ø10 mm axle, a 6-7 mm thick slat for a width of 24 mm. Total mass of approximately 150 g.

The mounting bracket (1)

The fixing bracket (1) is cut into a straight joist bracket; the 90° change of plane and its offset facilitates shaping. It can also be made from a square or a stamped sheet metal.

The fixing bracket (1) is fixed to the guide housing of the tool by the screw(s) which hold the chain guide and the housing. This allows the correct positioning of the slat (2) in the calibration position. In fact, the slat (2) must be placed a few millimeters in front of the front casing but a few millimeters back from the felling claw so as not to be stressed by the material being cut and not to reduce the length capacity. of the guide used as presented by the .

The fixing bracket (1) is pierced with different holes whose diameter differs depending on the function:

• The hole(s) (14) which allow the fixing of the fixing bracket to the guide housing of the tool. They are on the vertical part of the mounting bracket.
• The pivot pin hole (15) allows the fixing of the slat and its movement relative to the tool. An identical hole is present on the plastic slat. This hole allows the passage of the pivot axis (5). It is present on the horizontal part of the fixing bracket, offset to the front.
• The stop hole (10), its bolt (11) and the nut (12) limit the amplitude of the angular sector to 160°, preventing the slat from coming into contact with the cutting zone.
• The holes which hold the slat in its two positions of use (rest and calibration) are called position housings (13). They are positioned on a circle whose center coincides with the pivot axis and are at least two in number (one per position, rest and calibration) as presented in Figures 8 and 9. It is possible to have several housings position by position to improve the stability of the system. They are chamfered on the underside to accommodate the stop screw(s) (7) present in the slat as shown in Figures 1 to 5.

These holes allow precise positioning of the plastic slat:

• Rest position:

The base of the plastic slat must be positioned between mid-height and the last upper third of the guide ( ) to come to rest on the piece of wood to be cut due to the slight bending imposed on the slat by gravity.

• Calibration position:

The angle formed by the guide and the plastic slat must be constant and equal to 90° to ensure a precise cut. In fact, the orthogonality allows the slat to be used as an additional mark on the sight when the guide is “embedded” in the wood ( ) because all bark has guidelines (for example, ash and oak have longitudinal lines in the direction of the tree's thrust while birch or cherry have radial lines).

Likewise, any pronation or supination is revealed by crushing the slat or lifting it. Thus, a glance is enough for the operator to ensure the correct positioning of the cutting tool thanks to the sight (3 or 4), the slat (2) while ensuring that the screws of stop (7) are in their position housing (13) because they are visible on the upper face of the fixing bracket.

Moving from the rest position to the calibration position (and vice versa) is facilitated by the pivot mechanism. Indeed, the presence of a flexible plastic or rubber washer (6), placed between the lower face of the slat (2) and the upper face of the steel washer (8) makes it possible to unlock the stop screw(s). (7) position housings. Proper tightening of the nut (8) must be ensured to ensure effective pivoting. In addition, this flexible system allows disengagement in the event of impact with an obstacle or loss of balance of the operator, reducing the risk of injury.

The plastic slat in the calibration position must be positioned back from the felling claw so that the fixing bracket is not stressed when the claw hits the material and in front of the front casing so that the contact point is on the guide, guaranteeing a start at a precise point. The flushness of the slat and the positioning at the end guarantee a controlled flow.

Fixing the tab (1) on the guide housing retaining screws makes the calibration device a removable accessory. It is possible to include a tab in the machining of the guide casing, allowing clipping or bolting of the plastic slat offering the aforementioned qualities. This makes it possible to transform the device into an option, rationalizing the full use of wood cutting tools. The integration of the device into the design of the tool allows for simplified use and better ergonomics.

It is also possible to equip manual tools such as pruners, branch cutters or any other tool suitable for the maintenance of green spaces with a suitable device (dimensions and ergonomics) incorporating the qualities described: locking housings for position of rest and calibration, end sight and intermediate sights.

The soft plastic slat (2)

Of variable width and thickness depending on the quality of the plastic and the tool equipped, the length of the plastic slat (2) is standardized at 50 cm from the cutting line by an end staff (4). It also allows calibration in multiples of 50 cm (1 m, 2m, etc.) by transfer as presented by the .

The plastic slat also includes intermediate sights (for example, fixed at 25, 33 and 45 cm from the cutting axis) allowing flows to be carried out at different lengths with the same tool. This makes it possible, for example, to cut previously tied bundles every 50 cm by using the 25 cm staff to cut on each side of the string.

The sights are made of flexible plastic or rubber (woven for greater longevity) and have a width slightly less than the width of the cutting line to allow the sight to fit into the previous marking as shown in Figures 15 and 16. The sights have a length of 4 to 5 cm and are fixed on top of the slat by a screw or rivet system (rivets being structurally less effective and tending to shear the sight).

The flexibility of the sights prevents any unintentional snagging that could lead to kickback or a risk of operator imbalance, reducing the risk of injury or tool breakage.

In addition to the pivot axis hole (15) previously mentioned, the slat also includes one or more holes (16) to accommodate the domed head stop screw(s) (7) making it possible to achieve the two positions (rest and calibration) in relationship with the position housings (13) as presented in Figures 1 to 9.

Please note that the stop screws (7) must not protrude beyond the underside of the plastic slat to avoid any snagging points which could interfere with the pivot mechanism or injure the operator.

A bidirectional graduation (from the base to the end staff (4) and vice versa), embedded in the slat allows calibration with centimeter precision on different lengths in addition to the staffs as presented on the . This also allows a different calibration than by simple transfer of the target as presented in the .

The precision flow is carried out from right to left to take maximum advantage of the possibilities of the device. However, it is possible to cut from left to right by taking visual cues without prior cutting.

Pivot mechanism:

The pivot axis consists of a screw (5) acting as an axis allowing the relative rotation of the slat (2) relative to the fixing support (1) through the axle holes (15). The screw (5) is held in position by the lock nut (9) and is completed by a steel washer (8) under the nut as described in Figures 6 and 7.

To allow passage from one position to another (rest to calibration and vice versa), it is necessary to have a disengagement:

• A release system by elastic deformation of a flexible washer (rubber or plastic). As described by the , the flexible washer (6) is inserted between the slat (2) and the steel washer (8). When the operator begins the movement to move from one position to another, the flexible washer (6) deforms elastically, allowing the screw (7) to be released from the position housing (13).

• A spring release system. As described by the , a spring (17) is inserted under the screw head (5) between two steel washers (8). The operator can thus disengage the system by compressing the spring by pressing on the screw head (5), releasing the screw (7) from the position housing (13). The compression travel of the spring must be greater than the height of the convex screw head (7) to allow movement.

Claims (7)

Device for calibrating the cutting of wood and plants, characterized in that it comprises a flexible slat (2) fixed to a fixing bracket (1) on a cutting tool, one or more fixing housings visible on the upper face (13) allowing the passage from the rest position to the calibration position orthogonal to the guide and vice versa using one or more rounded head screws (7) acting as a stop in the housings (13), an end sight (4) allowing calibration in maximum length (50 cm) and intermediate staffs (3) allowing calibration in other lengths (for example, 25 or 33 cm). Device according to claim 1 characterized in that the passage from the rest position to the calibration position (and vice versa) is facilitated by the deformation of a flexible washer (6) in the pivot mechanism. Device according to claim 1 characterized in that the passage from the rest position to the calibration position (and vice versa) is facilitated by the compression of a spring (17) in the pivot mechanism. Device according to any one of the preceding claims, characterized in that the front line of the slat (2) is positioned at the front of the front casing of the tool, set back from the felling claw and that the point of engagement is between the middle and the last third of the guide. Device according to any one of the preceding claims, characterized in that the slat (2) is graduated on both sides, from its base to its end to allow in-situ measurement. Device according to any one of the preceding claims characterized in that the fixing bracket (1) comprises a screw (11) and its nut (12) limiting the angular opening and any risk of destruction of the slat and the sights (3 and 4) by the cutting zone of the tool. Device according to the preceding claims, characterized in that the fixing bracket is originally integrated into the frame (guide housing) of the cutting tool.