Self-adjustable tool having parallel jaws

Abstract

The present invention relates to the automation of pliers having parallel jaws, the fastening part of which slides into a toothed cavity. A connecting rod (15) is inserted by means of a projection (22) in a groove (16) of the handle. The end (20) of the connecting rod slides over the bench. The connecting rod is subjected to moments produced by springs anchored at the ends thereof. Initially, the movable handle rotates around the projection (22) of the connecting rod and its protuberance (13), housed in a groove of the jaw (11), moves the same until it touches the part to be gripped. Next, vertical sliding of the protuberance (13) in the groove (11) causes the shaft (14) to raise and the triggers (24) are rotated, the teeth thereof making contact with those of the bench. The sliding of the projection (22) of the connecting rod and its end (20) allows the handle to rotate, the teeth (36) to be coupled, and the part to be pressed.

Description

[0001] DESCRIPTION

[0002] AUTO-ADJUSTABLE PARALLEL JAW TOOL

[0003] TECHNICAL SECTOR

[0004] This is a multi-purpose tool that replaces pliers, a nut wrench, and optionally, shears. Tightening nuts of various sizes is quick and easy, as the adjustment is automatic, requiring only one hand. It competes with ratchet wrenches because there's no need to remove the wrench from the nut, turn it 60°, and then re-fit it. (When tightening a nut and needing to return to the correct angle, simply release the pressure on the tool's arms, allowing the jaws to open and contour around the nut, which will remain stationary until the next tightening angle.) It's also important to note that, unlike standard open-end or adjustable wrenches, the tightening action isn't concentrated at the corners of the nuts; significant pressure is applied across the entire surface of both sides.This prevents, in some cases, the nuts from becoming rounded and the grip from failing when dealing with nuts with rough corners.

[0005] With this implementation, the advantages of the original tool (parallel jaws, which act with a force up to twelve times greater than that exerted by the operator) are combined with the convenience and speed of use (it is not necessary to initially adjust the tool manually) and the operator always has his second hand available to manipulate the piece.

[0006] The jaws can be changed in a few seconds, without tools, giving the tool great versatility. (The tool can be converted into shears by attaching a blade or, using the appropriate jaw, can firmly grip tubes up to 50 mm in diameter and extend the opening range to 50 millimeters.) BACKGROUND OF THE INVENTION

[0007] This tool consists of a self-adjusting system that automates the parallel jaw tool described in patent ES 20645S5 of 04 / 09 / 1989

[0008] It has similarities to another tool that has the same objective described in patent EP3160334 of 26 / 05 / 2014

[0009] However, the tensioning method of this project is essentially different, which allows it to overcome the need to use small teeth by incorporating very large teeth that provide adequate strength and reliability for professional use.

[0010] It shares some similar parts and structure with the two patents mentioned above, such as:

[0011] -The main body (which will be called the bench) comprising a handle, a jaw and a central body with guides and a toothed groove on its upper part.

[0012] -A jaw that slides over the guillas of the main body

[0013] -A movable sleeve whose articulation is positioned inside the slot and which has a small protrusion with which it displaces the sliding butt.

[0014] The self-adjusting parallel-jaw pliers, patent EP3150334, incorporate a device that, among other purposes, allows the jaw to be moved perpendicularly to the horizontal slot of the bed. In the prior art, it is observed that the handle shaft articulates with a small toothed rack on its upper face (Fig. 9, 49a). Its smooth lower face rests on and slides in the smooth surface of the slot in the bed. A vertical movement of the handle raises the rack, which, with a vertical translational movement, engages with the teeth on the roof of the slot in the bed. The shaft is then positioned, and the movable handle becomes a first-class lever that exerts a large force on the sliding jaw.

[0015] The inherent problem with this traditional design is the overturning of the toothed rack (Fig. 10 (49b)), which weakens the attachment of the movable handle shaft. The presented design incorporates innovations that overcome these drawbacks. It allows for the use of triggers with offset teeth, which in turn allows for the use of oversized teeth.

[0016] These new features result in a reliable and durable tool, making this design a product suitable for the professional sector.

[0017] EXPLANATION OF THE INVENTION

[0018] The project presented does not use these translational racks (49a) described in the prior art, but instead employs small cranks called triggers, consisting of one toothed end (52) and the other (51) consisting of a surface formed by sections of a circle (53, 55) that fits between the smooth surface (3) of the slot in the bed and the tips of its teeth (8), allowing it to act via a joint (56). Between these two ends, a drill accommodates a shaft (14) which also articulates a movable sleeve (12). This design has a significant impact on the behavior of the tool:

[0019] 1- The translation racks described above (49a), when used in this type of tool, are subjected to a very large horizontal force component (47) which induces an overturning torque (49b). (When this occurs, only the corner of the first tooth then makes point contact with the bed, unacceptably reducing the resistance, if the aim is to direct the force to the professional sector).

[0020] Obviously, the triggers (cranks) described here do not have this problem since they are always supported on the bottom of the groove and their teeth are designed so that in the rotated position the contact is global. 2~It is physically impossible to use two translation racks offset by half a tooth if they share the same axis. In the case of the triggers, described above, they can be offset by half a tooth and share the same axis (Fig. 13): When one of them is correctly engaged Fig. 13 (25a), the teeth of the other Fig. 13 (24a) are positioned at mid-height because, at the other end, notches (58) made in the upper part opposite the teeth limit the displacement produced by the push (58) of the teeth of the bed. (It is observed that the teeth of the bench, not coinciding with the notches (59) of the other trigger (25a) if they turn it completely).

[0021] 3~ The vertical movement (57) of the teeth is amplified Fig. 12 with respect to the vertical movement of the shaft, guaranteeing a faster coupling that uses little closing angle of the movable handle.

[0022] Before pressing a workpiece, to engage the teeth of the element that positions the handle axis, these tools use a large part of the angle of their handle opening (especially if the workpiece is thin). It could then happen that the complete closure of the handles does not produce enough movement in the jaws to firmly hold the workpiece (a problem that increases if the workpiece has a degree of elasticity).

[0023] This circumstance made the use of large teeth prohibitive because the initial "consumption" of the opening angle became excessive. Small teeth, besides being less resistant, are more prone to wear and can become fouled with dust or metal filings.

[0024] One way to overcome this problem is by using two offset triggers with teeth that allow the teeth to be twice as long and twice as tall, quadrupling their volume. The device that produces the initial rotation of the movable handle (12), followed by the vertical displacement of the movable handle, can be achieved with a single connecting rod (15) that does not interfere with the complete closure of the handles. This provides a greater rotation angle than known embodiments and contributes to a possible even greater increase in the size of the teeth. An additional feature is that the spring (18) can be forced out and the protrusion (19) on the lower part of the connecting rod (15) disengaged (Fig. 17). This allows the movable handle (62) to be rotated sufficiently to dislodge its protrusion (13) from the groove (11) of the sliding jaw. In this way, the jaw can be quickly disassembled without tools and replaced with another sliding tool.

[0025] BRIEF DESCRIPTION OF THE DRAWINGS Accompanying this description as an integral part is a set of drawings ®n which, for illustrative and non-limiting purposes, depict the following:

[0026] Figure 1a - Shows the project as a whole.

[0027] Figure 1b - Shows the fixings of the ice springs and their possible sliding along the wall (17) and the possible travel of the projection (22) in the groove (18). Figure 2 - Shows the force (26) produced by the connecting rod on the movable sleeve.

[0028] Figure 3 - Shows the sliding jaw in contact with the piece to be grasped, and the following movement (20) of the movable sleeve

[0029] Figure 4 shows the instantaneous center of rotation (30) that determines the movement of the handle, and which will bring the trigger teeth close to the groove. Figure 5 shows the trigger teeth and bed touching, but not engaged (33), and shows the rotation (34) that will then occur.

[0030] Figure S, « Shows the teeth touching and fitting (38), shows the sliding of the connecting rod projections (35) and (38) and the next rotation (37) that is to occur.

[0031] Figure 7 ~ Shows the movable handle acting as a first-class lever, pushing the movable jaw and compressing the workpiece.

[0032] Figure 8.- Shows the inclination of the sliding jaw slot (43) and the forces appearing on the movable handle (A vertical force component (42) acting on the handle is observed.)

[0033] Figure 9.~ Corresponds to a configuration described in the prior art, which uses a translational rack (49a). It shows the force (47) exerted by the rack shaft on the rack (49a). It is separated by a distance (48) from the tip of the rack tooth, producing a tilting torque.

[0034] Figure 10," corresponds to a configuration described in the prior art. It shows the rack (49b) turning over if the force (47) of the shaft acting on it approaches the horizontal.

[0035] Figure T1 shows a trigger (50) that behaves like a small crank attached to a drouisr end (51) opposite the teeth. The force (54) exerted by the bed, achieving balance in the moment equation, is shown.

[0036] Figure 12 shows how the upper surface (55) acts as a ball joint and how the resulting rotation amplifies the vertical movement (87) of the teeth. Figure 13 shows two identical thin triggers (24a) and (24b) whose teeth are offset from the teeth of the central trigger (25a). Two notches (58) and (59) are located on the upper surface opposite the teeth. Depending on the situation, the notches (58) can reduce the trigger's travel, causing its teeth to be positioned at mid-height. In this way, when one trigger is engaged, the other offset trigger (24a) does not interfere with the teeth of the bed. Figure 14 shows an alternative configuration of the triggers.

[0037] Figure 15.- Shows another alternative configuration of the triggers (using only two triggers of the same thickness) Figure 16.» Shows in the left column the large trigger (25a) fitted and the small trigger (24e) with its teeth offset, mounted on the same axis, not fitted, (note the need for the notches (58b) to limit its rotation.)

[0038] The right-hand column shows how the triggers exchange roles when they are moved horizontally a length corresponding to half a tooth. Figure 17 shows how to separate (60) the protrusion (19) of the connecting rod, dislodge (81) the spring (18), in order to rotate (62) sufficiently to extract the jaw.

[0039] Figure 18 shows how a fixed stop (63) on the movable handle limits the opening of the tool (65), and how moving this stop (69) allows for a greater opening. It also shows how to make this stop adjustable by incorporating a screw (67).

[0040] Figure 19.» Shows another embodiment of te heramienta by replacing the sliding connecting rod with a compressible crank (70).

[0041] Figure 20.- Shows air embodiment of the tool by replacing the sliding connecting rod with two cranks, the rotation of the crank articulated on the bed being limited by a tuft (76).

[0042] Figures 21 and 22.» Show some constructive variations of realization 1.

[0043] Figure 23 - Summary figure. PREFERRED EMBODIMENT OF INVENTION No. 1

[0044] The tool comprises four main parts, Fig.1: 1) A part (1) which, being the most extensive part of the tool, will be called the bed and is formed in pairs;

[0045] ~ a mango (2)

[0046] - one of the jaws (4) of the tool.

[0047] - a central zone comprising grooves (5), perpendicular to the straight side of the jaw, and an elongated cavity (3), parallel to the groove, with the lower side smooth and the upper side presumably toothed (6).

[0048] 2) A sliding marxiíbula (7) formed by:

[0049] ~ a gag (10)

[0050] ~ a central wa comprising protrusions (8) that will be housed in the grooves (5) of the bench.

[0051] - some inverted U-shaped grooves (11) attached to the jaw and inclined at an angle (43) to the vertical, which will give rise to some protuberances (13) of the upper end of a movable handle (12). The angle (43) of inclination produces a vertical component (42) in the forces that the jaw makes on the protuberance of the movable handle.

[0052] 3) A movable handle (12) with the head drilled to accommodate a shaft (14), with protrusions (13) at the extremities whose edges will push the surfaces (0) of the sliding jaw (7).

[0053] 4) A connecting rod (15) with two perpendicular projections near its ends, sliding the projection (22) of its upper end in a groove (16) located in its upper first third and half of the movable handle (12), the projection (13) of its lower end stopping against projections (21) of the handle (2) of the bed (1),

[0054] The lower end (20) of the connecting rod rests on the inner wall (17) of the crankshaft. A spring (18) attached to the crankshaft (1) acts on the lower end of the connecting rod (20) that protrudes from the projecting axis (10), producing a torque that tends to rotate the connecting rod (1b) downwards.

[0055] At the upper end of the connecting rod (15) that protrudes from the projecting axis (22), a spring (23) acts, attached to the movable handle (12). The torque of this spring tends to rotate the movable handle (12) and, consequently, to fully open the jaws. Other parts include:

[0056] ™ A shaft (14) on which the head of the movable handle (12) is articulated and triggers (24,25) are articulated which in combination with the teeth (6) of the bed form a ratchet system.

[0057] - A trigger (24) formed by a central zone (50), where a drill is located in which the axis (14) of the movable handle is articulated, a first protrusion whose end is toothed (52), and a second protrusion opposite the first, whose end is formed by sections of circular profile (53), (55) that fit between the sole (3) of the elongated bed and its toothed roof (5). The trigger uses these surfaces of its circular profile, which act as a ball joint, to rotate Fig. (12) when the axis (14) moves perpendicularly to the slot of the bed.

[0058] - Another similar second trigger (25), half a tooth longer, which shares the same axis and whose teeth are offset with respect to the first trigger. The triggers have notches (58), (59) on the upper part of the end opposite the teeth which, in some situations, prevent the teeth of the bed from rotating them completely, leaving their toothed end halfway open. Operation:

[0059] The tool performs four operations sequentially and automatically, which are described below: 1 - Approach phase towards the piece that is intended to be grasped, (from Fig.2 to Fig.3):

[0060] Initially, due to the pretension of the connecting rod (18), the lower spring (19) of the connecting rod (15) engages the teeth (21) of the bed handle, converting this spring (19) into a fixed axis. Considering the balance of the connecting rod with respect to this axis, it is observed that, to counteract the action of the connecting rod (18), the movable handle (12) must exert an upward force on the connecting rod (15). It follows that the connecting rod exerts a downward force on the movable handle: This force (28) ensures, in each initial displacement, that the teeth of the triggers (24, 25) remain away from the teeth (6) of the bed. The movable handle (12) will rotate (27) around the lower end of its groove (16) in contact with the protrusion (22) of the connecting rod that acts as an axis with respect to the handle, because the prestressed spring (23) keeps it in contact with the lower part of the groove.This axis will have a small movement perpendicular to the connecting rod because this connecting rod will rotate slightly about its lower axis (19).

[0061] Fig 3 shows the trigger teeth still separated (28) and the displacement (29) of the trigger axis (14) that will occur next.

[0062] 2~ Phase of establishing contact between the teeth, (from Fig.3 to Fig.5):

[0063] When the jaw is immobilized by touching the workpiece, the handle protrusion (13) can only slide along the small, inverted U-shaped groove (11) of the sliding jaw (7). The instantaneous center of rotation (30) of the movable handle will be perpendicular to this groove and passing through the point of contact. Its position is determined by its intersection with the extension of the connecting rod (15), which acts as a crank (since its projections serve as axes in this phase). Consequently, the force (32) exerted by the operator on the movable handle (12), thanks to the lever arm (31), will cause it to rotate about this instantaneous center of rotation (30), and its protrusion (13) will engage the inverted U-shaped groove (11) of the jaw. This approximately vertical movement of the handle is made possible by a slight rotation of the connecting rod (15) about its lower axis (19).

[0064] The shaft (14) of the trigger (24) will rise and the trigger (which is a small crank) will rotate (56) with respect to the end opposite its teeth and these will rise until they make contact with the teeth of the groove (33).

[0065] Figure 5 shows the following rotation (34) in which the protuberance (13) will act as a ball joint. 3- Tooth engagement phase from Figure 5 to Figure 6:

[0066] Figure 5 shows that the teeth are in contact (33), but not engaged. The bed (1), handle (12), and connecting rod (15) form a rigid, hinged triangle. Therefore, the angle formed by the handle (12) and the bed can only decrease if at least one of the connecting rod's joints gives way. This occurs when the gaps (32) increase and at least one of the springs (1B) and (23) lengthens.

[0067] The upper shaft (22) of the connecting rod will begin to rise (35), moving along the groove in the handle. The inner shaft of the connecting rod (19) will begin to descend, separating (38) from the projection (21) of the handle on the bed. The protrusion (13) of the movable handle (12) will act as a ball joint around which the rotation will occur. This rotation (34) causes the trigger to retract until its teeth engage with those in the groove (36).

[0068] The rotation (37) that will be initiated around the axis (14) of the trigger (24) is shown. 4~ Phase of gripping and compressing the piece from Fig. 1 to Rg. 7;

[0069] When one of the triggers (24,25) is locked, its axis is immobilized and the movable handle (12) becomes a first-class lever. Since the handle is 12 times larger than the lever arm of the protrusion, it follows that the force exerted by the operator at the end (44) of the handle is multiplied by 12, pushing the jaw (in traditional pliers this ratio is 3 to 4). The reaction force (45) exerted by the sliding jaw (7) on the protrusion (13) of the movable handle (12) has a vertical component (42) which is achieved thanks to the angle (43) of inclination of the support surface (9) of the groove (11) of the sliding jaw (7).

[0070] This realization allows for small vahant variations (Rg, 21 and 22):

[0071] - Instead of using the lower external part of the connecting rod (20) and the inner wall (17) of the main bearing sleeve (2), the lower connecting rod spring is used

[0072] (19) sliding it on the outer edges (81) of the connecting rod handle

[0073] - Another option is to make a groove (S3) in the handle of the bench where the lower insulator (19) slides.

[0074] ~ You can remove the slot (16) from the mobile sleeve and use the outer edges (82) of the mobile handle instead

[0075] - Another variant is to convert one of the connecting rod protrusions into a permanent joint while maintaining the other protrusion as a sliding joint. PREFERRED EMBODIMENT OF THE INVENTION No. 2

[0076] Embodiment n® 2 (Fig. 19) is similar to embodiment n® 1, with the sole exception that the connecting rod is replaced by a piston and cylinder assembly (70) (slider) in which a pre-compressed spring (72) is located. The assembly behaves as a rigid link unless an axial force exceeding the spring's pre-compression is applied. If this force is exceeded, the spring yields (74), allowing the movable handle (73) to rotate even though the axis (14) of the movable handle and triggers is immobilized.

[0077] PREFERRED EMBODIMENT OF INVENTION No. 3

[0078] In this embodiment (Fig. 20), a crank (75) is subjected to a torque produced by a spring housed in the handle of the bed, which tends to rise, forcing it to remain in contact with a stop (76), making its end, during the process of approaching the workpiece to be grasped, a fixed point (77). Once contact is established and increasing the force on the handle, the spring will yield, the crank will descend (78), separate from the stop (79), and allow the movable handle to rotate (80) even though the axis (14) of the movable handle and the triggers is immobilized.

Claims

CLAIMS -1) Self-adjusting parallel jaw tool, comprising, - a bed (1) consisting of a handle (2), a jaw (4), grooves (5) perpendicular to the straight side of the jaw, an elongated horizontal cavity parallel to the grooves, with the lower side smooth (3) and the upper side (6) toothed. - a jaw (7) sliding with respect to the bed (1) thanks to projections (8) that engage with the grooves (5), and which consists of a second jaw (10) and grooves (11) opposite the jaw, in the shape of an inverted U with support surfaces (9). - a movable handle (12) with a drill in the upper groove through which a shaft (14) passes, which has protrusions (13) that fit into the grooves of the sliding jaw (7) and are kept in contact with its support surfaces (9). - at the hands a trigger (24), coaxial with the axis (14) of the movable handle (12), this trigger joint being located between its extremities. - a connection between the bed and the movable handle formed by at least one kinematic link with transverse axes at its ends, initially making the upper axis (22) the axis of rotation of the movable handle. and characterized, - because the trigger (24) is formed by a central zone (5G) with a hole that houses the axis (14), a first projection whose end is toothed (52), and a second projection opposite the first, whose end is formed by sections of circular profile (53 and 55) that fit permanently between the smooth lower side (3) of the elongated cavity of the bed and the toothed upper side (6). ~ and because the trigger pivots (56) on the end opposite its teeth when its axis, which it shares with the movable handle, is subjected to a movement with a component perpendicular to the elongated cavity of the bench, this movement being produced by the movable handle whose upper protuberance (13) slides at that moment in the groove (11) of the jaw.- and because, in the process of approximating the sliding jaw, the. The connection between the bed and the movable handle behaves like a crank that rotates about a fixed axis (19) of the bed and with its other end rotating about a fixed point (22) of the movable handle - and because, when the jaw stops on the piece to be grasped, the connection between the bed and the movable handle defines the instantaneous center of rotation of said handle (30) in a position that will induce it to move vertically. - and because, when the teeth of one of the triggers and those of the bed come into contact, the connection between the bed and the movable handle stops acting as a rigid crank, allowing the handles to close. ~ 2) Self-adjusting parallel jaw tool according to claim 1 characterized, - because it has a second trigger (25), coaxial with the first, whose teeth are offset by half a tooth from the teeth of the first trigger (24), with the engagement with the rack occurring alternately with each of the two triggers. - and because each trigger has notches (58 and 59) on the upper part of the extremities opposite the teeth that coincide (58a), (59a) with the tips of the teeth of the bed, when, and only when, it is not the turn of said trigger to engage, the other trigger doing so, which, at that moment, is turned completely by the teeth of the bed, which in this position do not coincide (59b), (58b) with the notches. ~ 3) Self-adjusting parallel jaw tool according to claim 1, characterized in that the kinematic link connecting the bed and the movable handle has a connecting rod (15) with perpendicular projections near its extremities, the projection of the upper extremity (22) being threaded into a groove (16) made in the movable handle (12), and characterized in that the projection of the lower extremity (19) is immobilized by colliding with stops (21) belonging to the handle of the bed. - 4) Self-adjusting parallel jaw tool according to claim 3 characterized in that the groove (16) made in the movable handle is replaced by the upper wall of the movable handle (82) on which the upper projection of the connecting rod (22) slides. - 5) An adjustable parallel jaw tool according to claims 3 to 4, characterized in that the lower end (20) of the connecting rod (15) is in contact with, and slides on, the inner wall (17) of the handle of the bed (2) - 6) Self-adjusting parallel jaw tool according to claim 3 and 4 characterized in that the contact of the lower end (20) of the connecting rod (15) is replaced by sliding its lower projection (19) on the surface (81) or (83) of a groove made in the handle of the bed (2). - 7) Self-adjusting parallel jaw tool according to claims 3 to 8, characterized in that it has a spring (23) anchored at the upper end of the connecting rod (15), and in the movable sleeve (12), producing a torque and allowing, when expanded, the projection (22) of the connecting rod (15) to move along the groove (18), and in that it has another spring (18) anchored at the lower end of the connecting rod. (15), and on the bench, producing a torque and allowing, as it expands, the lower projection (19) to descend. - 8) Self-adjusting parallel jaw tool according to claims 3 to 7, characterized in that the kinematics are simplified by reducing one of the slots (16) or (83) to a point, making it a fixed joint. - 9) Self-adjusting parallel jaw tool according to claim 1 characterized in that a projection (63) belonging to the movable sleeve (12) limits the opening of the tool, achieving an increase in said opening by applying a force (69) on this projection (63), which produces a translation of the movable handle and the sliding jaw. - 10) Self-adjusting parallel jaw tool according to claims 3 to 6 characterized in that the lower projection (19) of the connecting rod does not thread into any groove, making it easier to disengage it from the stop (21) of the handle on the bed, separate (60) the connecting rod, dislodge (61) the spring and rotate (82) the movable handle sufficiently to remove the sliding jaw. - 11) Self-adjusting parallel jaw tool according to claim 1 characterized in that the kinematic link connecting the bed and the movable handle (12). with a compressible crank (72) formed by a telescopic system with a pre-compressed spring, this joint behaving as a rigid connecting rod until the pre-compression of the spring is exceeded. - 12) Self-adjusting parallel jaw tool according to claim 1 characterized in that the kinematic chain of connection between the bed and the movable handle (12) is constructed with two cranks subjected to certain forces and one of them (75) being initially blocked by a stop (76).

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