DE1678400A1 - Reversible ratchet - Google Patents

Description

PA TBNTAN WXL TE PATENT LAWYER DiPL-ING. R. MOLLER-BORNER PATENTANWALT DIPL.-ING. HANS-H. WEY BERLI N-DAHLEM 33 · PODBIELSKIALLEE «8 8 MÖNCHEN 22 -WIDENMAYERSTRASSE TEL. 0311 742907 TELEGR. PROPINDUS TELEX 0184057 TEL. 0811 -225585 ■ TELEGR. PROPINDUS · TELEX 05 ·>"· ■

21st

Pendleton Tool Industries, Inc., Los Angeles, California (USA)

Reversible ratchet

The present invention relates to a tool, in particular a reversible ratchet for transmitting a drive lever exerted torque on a tool to be operated by the ratchet, e.g. a socket wrench, for tightening nuts, bolt heads, etc., whereby the ratchet has a Head with a drive lever with a recess and arranged therein, toothed on its circumference ratchet wheel with a Has coupling shaft for placing the tool.

Such ratchets are produced and become known in numerous variations. There were constant improvements for the purpose of reaching larger ones, given by these ratchets Desired advantages, in particular simple construction, compact design and low weight «

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The subject of the present invention compares " bare ratchet has a drive lever, a ratchet wheel and a ratchet mechanism, the latter includes a pawl through which the torque is transmitted from the drive lever to the driven ratchet wheel. Many of the earlier designs are characterized by a single, double-acting lock · » latch that moves back and forth between two different positions or around one centrally located Pivot swings. The shapes and arrangements of the various pawls are such that in the pawl a high bending load or shear load arises when a load is applied by means of the drive lever occurs β This imposes certain restrictions on the position of the pawls that could not be removed until now · One of these ratchets is in the US patent 893 Ο97 by J.M. Reams have been described; the present The ratchet is to be regarded as an improvement over the construction mentioned. "

In the manufacture of tools in general, and in the manufacture of ratchets in particular, there is a strong one Competition, As a result, an improvement that reduces manufacturing cost is a definite one Competitive advantage in the market, an advantage that

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can be very considerable, even if the improvement is modest in design.

One of the particularly complex parts of a ratchet when manufacturing is the pawl, it used to be common to machine the pawl from a solid piece of metal. Because the pawl with precision and accuracy must be established when the ratchet mechanism works reliably and properly should be guaranteed, the production of pawls was carried out by machine; necessarily beat however, the machine operations result in a relatively high price of the end product.

One produced according to the methods of metal-ceramic The pawl can be manufactured economically with the degree of precision desired; but such a pawl creates new construction problems, because the object produced in this way is relatively weak against material or shear stress. Therefore, this method is not suitable for pawl constructions with high bending loads or shear stresses suitable «The pawl obtained by a metal-ceramic process only fulfills the requirements if it is in is essentially very resistant to compression forces; Weakness against shear loading due to this type of

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Turning force occurring in tools leads to the loss of the ratchet teeth "

As a result, it was an object of the present invention to provide the ratchet mechanism for a reversible To improve ratchet, the use of metal-ceramic applied to the manufacture of a pawl will j resulting in a much lower cost than machining a steel blank Case would be "

In particular, it is the object of the invention to provide a new construction of a reversible ratchet at which the ratchet mechanism is essentially only under compressive pressure when loaded to To transmit power from the ratchet drive to the tool, etc. coupled to the ratchet, whereby the manufacturer of pawls the use of economical metal-ceramic processes is made possible.

Another object of the invention is to provide a ratchet with the above-mentioned properties, which are also distinguished by a small number of main parts, simplicity of construction and reliable work, so that the through the new Manufacturing process for the manufacture of the pawl

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the cost savings achieved are not at the expense of other desirable properties of the ratchet, _etc.

The solution of the set objects and the attendant attainment of the desired advantages are achieved according to the invention in that in a ratchet of the type described at the beginning the recess is designed in such a way that two freely movable pawls are arranged therein, each with a toothing join with the teeth of the ratchet wheel in a force acting on the head driving force to engage and transmit the driving force to said ratchet wheel, and that a reversing device is provided die.wahlweise betätigt.eine the pair of pawls against the engagement in the toothing of the ratchet wheel secures _t and spring means , arranged and supported on the two pawls for pressing in a pawl in toothing with the ratchet wheel

In a preferred embodiment of the invention, pushes each pawl when it is driving with the ratchet wheel engages with its opposite side against a curved portion of the wall of the recess; This curved section is expediently a circular arch and the barrier touching the wall The latch surface is curved in the same way in order to ensure maximum mutual contact area «here

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it is intended that the mutually engaged » the surfaces of the teeth of the pawls and the batschen · » radθs in the state of loading the pawl, respectively are arranged in a plane which runs perpendicular to a radial line, the starting point of which is the mean point of the curved recess wall, this Pass lines through the pressure transmitting surfaces of the teeth.

Two individual, separate pawls are provided in the recess and between these two pawls and held by these a spring is provided, which presses the pawls apart »a switching device brings one of the pawls into driving engagement with the ratchet wheel and releases it this again while the spring presses the other pawl into driving engagement with the ratchet wheel

For a better understanding, reference is made to the following. description and the drawings, such as the recited objects and advantages of the present invention as well others, not specifically mentioned, can be reached; show it:

Fig. 1 is a perspective view of part of a inventively constructed ratchet, the lan head and is part of the lever}

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Fig »2 shows a longitudinal section through the center of the head and of the ratchet mechanism along line 2-2 in Fig. 1;

3 shows an enlarged partial section along the line 3-3 in Fig. 2, the two 'freely movable pawls and a part of the ratchet, wherein the Pawls, based on the illustration, are in a position for counterclockwise rotation are located;

4 shows a view according to FIG. 3, but with the pawls, based on the illustration, for clockwise rotation into the second or »reverse position are shifted;

... 5 shows a part of a section along the line 5 5 in Figure 2 ^ in the same MaBstab as shown in Figure 3, a rotatably mounted lever mechanism for the lock latch reversal control pointing;

Fig. 6 is an enlarged portion of a section taken along line 6-6 in Fig. 2 showing a spring loaded Shows ball lock of the shift lever;

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Figo 7 shows an echematic representation in an even bigger range Scale showing a pawl in drive-related engagement in the ratchet wheel and the arrangement the teeth of the pawl and ratchet wheel are facing each other.

The ratchet shown in FIG. 1 has a head 10 formed in one piece with a drive lever 11. Here only part of the lever is shown, which extends over an appropriate length from the head and on the end remote from the head 10 has a handle

As can be seen in particular from FIG. 2, the head 10 a slot-like recess 12 which is open to one sidej in this recess is a ratchet wheel rotatably mounted »The ratchet wheel 14 has a short hub 15 which is inserted into a bearing recess on the bottom of the recess 12 engages “on the other side of the ratchet” wheel 14 is a square coupling shaft 16 to be placed on a wrench or other tool for transmitting rotary motion to a nut, a screw bolt or the like arranged

The ratchet wheel 14 is on its periphery with one of a large number of shown in more detail in FIGS Teeth 18 existing teeth provided »The

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Teeth 18 run in the axial direction of the ratchet wheel 14 and are evenly spaced from one another. These teeth 18 represent the drive teeth, which with the teeth 18 of the same size and shape of the pawls in Intervention as described below.

The ratchet wheel 14 is in the recess 12 in his Position held by a cover plate 20, which has an opening for receiving a bearing shoulder 21 of the ratchet wheel 14 which has a smaller diameter than the ratchet wheel 14 with the shift teeth 18, the cover plate 20 is again secured by a snap ring, the $ n one Groove 22 in the wall of the recess 12, which is outside the cover plate 20 is engaged "

In order to transmit a torque from the head 10 to the ratchet wheel 14 and thus to rotate the coupling shaft 16, are Pawls provided. These consist of a pair of freely movable pawls 24 and 25, which are mirrored » figuratively the same, so that they turn right or left Represent elements that can be alternately brought into engagement with the teeth 18, as in FIGS 4 is shown.

As can be clearly seen from the illustration of the pawl 24 in FIG. 7, each of the pawls 24 and 25 formed triangular in rough outline. Along one

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teeth 26 are arranged on their sides, which can come into engagement with the teeth 18 in a form-fitting manner. A further side 27, which may be referred to as the teeth 26 opposite is curved so that these savings curvature with a curvature of an associated wall 12a of the Off "12 identical ivt ₀

The recess 12, which can also have a different shape, if so desired, is substantially circular in cross-section and its diameter is slightly larger than the outer diameter of the ratchet wheel 14 including of the shift teeth 18, however, has a bulge 12b which, as is very clearly shown in FIG. is formed by the curved wall 12a * The wall 12a is expediently held in the shape of a circular arc, wherein the center of curvature is located at 28, at a distance from the center of the recess 12,

* ■■ = - this being coaxial with the axis of rotation of the ratchet wheel 14 is. The curvature of each pawl, imparted to a side wall 27 opposite the teeth 26, serves the same as that of the wall 12a, so that the pawls 24, 25 in all of them are within their range of motion lying arrangements are completely in contact with the wall 12a and slide just as easily on this wall 12a can*

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Both pawls 2k and 25 are mounted in the bulge 12b formed by the curved wall 12a, being slightly less than that in the bulge 12b

take up available space. The opposite Surfaces of the two pawls are provided with flat holes in which the two ends of a Support compression spring 30. Usually the compression spring is 30 slightly compressed, whereby the pawls 24, 25 be pushed apart.

Since it is advisable that only one specific pawl comes into engagement with the shift teeth 18, a pawl reversal control device is provided which not only reverses the direction of the ratchet action, but also releases the respective pawl from the teeth 1b. The reversing device consists of a two-armed shift lever 32 which, as shown in FIG. 5, is mounted in its center and thus swings about an axis formed by a bearing pin 33. The two arms of the shift lever 32 slide over the bottom of the recess 12, and in the pivoting range of each of the arms there is a short pin 35 on the side of the pawl 2k or 25 facing the bottom. The pin 33 »on which the shift lever 32 is pivotably mounted, extends so far outward through the head 10 that it carries an outer manually operated advance lever 36 through

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which the operator of the tool can optionally pivot the Sch.aXth.ebel 32 into two end positions. One end position of the shift lever "} 2 is shown in solid lines in Fig. 5, while the other EiriLage is shown in phantom in Figo h.

As will be explained in more detail in the following description, it is expedient for the shift lever 2 to be resiliently held in each of the two end positions. For this purpose, a spring loaded ball lock 38 with a locking spring is provided in the bearing pin 33, which can snap into one of two notches 39 in the bearing wall for the bearing pin 33. If the locking spring yields and thus counteracts the ball lock 38 being pressed in, it can also roll over the elevation between the two notches 39. Open This catfish gives the ball lock 38 to the pressure exerted by the operator on the advance lever 36 in order to move the switching lever 32 from one position to the other; if the ball lock 3 & however engages in a detent 39, the force of the locking spring 40 is without counteracting pressure by hand is sufficient to hold the shift lever 32 in its desired position at the furthest end of the pivoting range.

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When the shift lever 32 approaches an end position, an arm of the shift lever 32 grips a pin 35 of a locking pawl and releases the respective locking pawl from its positive connection with the teeth 18, more precisely when the shift lever 32 is in the position shown in FIG 4 is the position shown in dashed lines, it detects the pin 35 on the pawl 24 and holds the pawl 24 in a position outside of the teeth 18 Position is moved, the other arm of the shift lever 32 moves and grips the pin 35 of the pawl 25 » The movement of the shift lever 32 moves the pawl 25 away from the teeth 18, and at the same time the pawl slides with its curved side wall along the surface of the curved wall 12a in order to lift the pawl 25 out of the teeth 18 Shift lever 32 has been released on the other pawl 24 is sufficient to bring the pawl into drive connection with the teeth 18, as has been shown in FIG.

The effectiveness of the drive lever 11 is in this way by the operator of the tool by pivoting the Vorstellhebols 36 clockwise, based on the character " in the one shown in Fig. 5 in broken lines

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set position deflected, with the bearing pin 33 around a Angle 41 is rotated. The reverse movement of the Bearing pin 33 moves the shift lever 32 back into the position shown in broken lines according to FIG. 4, in which the switching lever 32 with the pin 35 the pawl 24 is in contact} this movement of the shift lever 32 disengages the pawl 24 with teeth 18,

At the end of each pivoting performed by the switching lever 32 , a pawl is freely movable and can only move along the wall 12a under the action of the force emanating from the locking spring 30, and as a result, this free pawl is now turned into a driving mode by the locking spring 30 Engagement with the teeth 18 urged. When the pawl 25 is now driven, a clockwise rotational force (cf. Fig. 4) is transmitted from the head 10 via the pawl 25 to the ratchet wheel 14 in order to turn the drive shaft 16 clockwise. A torque in the opposite direction is exerted by the engagement of the pawl 24 in the ratchet wheel 14, as shown in FIG Torque in one

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the opposite direction to the drive torque the pressure of the compression spring 30 moves along the wall 12a and thereby released from the drive connection «This allows torque to be transmitted from the ratchet lever to each drive direction,

When one of the two pawls is in the torque transmitting position, it is forced between the wall 12a of the recess and against the teeth, with its own teeth 26 engaging the ratchet teeth 18 a position in which they torque ent "counterclockwise on the ratchet wheel 14 transmits" the driving force of the driving lever 11 is transmitted by the pawl 24 via the systems 26a perpendicular to the teeth 18 of the ratchet wheel Ik. Since these systems 26a are designed so that they are perpendicular to a radius whose center is at 28 and which passes through the middle of the tooth surfaces, it follows from this that the torque transmitted to the ratchet wheel 14 via each system 26a acts on a radial line, which goes through the center 28, and accordingly runs perpendicular to this wall 12a at the point of intersection of a radial line with the wall 12a, which is due to the fact that the center 28 is the center of curvature of the wall 12a, since the teeth 18 are equally spaced at the

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Circumference of the ratchet wheel 14 is arranged, the direction of the force transmitted to each tooth 18 changes uniformly along the circumference of the ratchet wheel _a

The teeth 26 of the pawls are expediently designed so that their surfaces are at an angle of 90 to one another, as shown in FIG. 7, and the angle enclosed by the surfaces of the teeth 18 should be less than 90; the number of degrees of the angle results from the number of teeth on the circumference of the ratchet wheel Ik _9. Since all teeth are symmetrical, the relationship between the teeth and the forces transmitted is the same for both pawls 2k and 25.

From the above description it can be seen that there are many individual modifications in construction and relationship of the parts can be made to one another "without this being a deviation from the inventive concept and represents the scope of the invention. As a result, the foregoing description is illustrative only and not to be regarded as limiting the invention as characterized by the appended claims.

Everything in the description belongs to the invention included and or, or is shown in the drawing, including what deviates from the specific exemplary embodiments are obvious to the person skilled in the art.

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Claims (1)

PA TEN TA N WÄL T6 s $ iorns 1 6 7 8 A O c / l Qi? ey 03, 'I. ^ 907TEUGR PRO ^ NDUS TELEX 0.84057 TEL. 08.1 225585 TELEGR. PROP.NDUS. TELEX 0524244 21st Pendieton Tool Industries, Ine ,, Los Angeles, California (USA) Claims χ 1Jüm-controllable ratchet for transferring one from one Drive lever exerted torque on a tool to be operated by the ratchet, e.g. a socket wrench, For tightening nuts, bolt heads, etc., the ratchet having a head with a drive lever with a recess and arranged therein, toothed on its circumference ratchet wheel with a coupling shaft for placing the tool, characterized in that the recess is designed so that in this two freely movable pawls are arranged, each with a toothing, which with the toothing of the ratchet radθs when a driving force is applied to the head come into engagement and the driving force on this 109848/003? Transfer ratchet wheel, and. that a reversing device is provided, which, optionally actuated, one of the two pawls against engagement in the teeth of the Ratchet wheel secures, and spring means, arranged and supported on the two pawls for pressing a pawl in toothing with the ratchet wheel. 2. Reversible ratchet according to claim 1, characterized in that the reversing device can be pivoted from a consists of a shift lever (32) mounted on a bearing pin and a spring-loaded locking device (3 & »40), the switch lever (32) resilient in one of the holds both end positions. 3. Reversible ratchet according to one of claims 1 and 2, characterized in that the pawls (24, -25) are molded parts made from metal powder. | k. Reversible ratchet according to claims 1 to 3 »characterized in that each pawl (24, 25) which is in driving engagement presses on one side against a curved section (I2a) of the wall of the recess (12), the with the wall (12a ) in contact with the pawl side (27) has a similar curvature. 103848/0032 5. Reversible ratchet according to claims 1 to 4, characterized in that the curved portion (12a) of the Wall of the recess (12) and the pawl sides that come into engagement with it are arc-shaped » 6. Reversible ratchet wrench according to claims 1 to 5 characterized in _t that are mutually engaged · " the surfaces of the teeth (18,26) of the pawls (24,25) ^ m and the ratchet wheel (14) in the state of loading The pawl (24,25) are each arranged in one plane, which runs perpendicular to a radial line, the starting point of which is the center point (28) of the curved recess wall (12a), these lines passing through the pressure-transmitting lines Pass surfaces of the teeth (18,26). 7 · Reversible ratchet according to claim 6, characterized in that the reversing device can be pivoted from one mounted in the head (10), with the respective locking ™ pawl (24,25) engaging shift lever (32) and a spring-loaded locking device (38,40) consists, which holds the switching lever (32) resiliently in one of the two end positions in contact with a pawl (24, 25). 8, reversible ratchet according to one or more of the claims 1 to 7f otherwise as described and or "or shown" 109848/003? Blank page COPY