DE8807386U1 - Torque wrench - Google Patents

Description

COHAUSZ & FLORACK

PATENTAN WALTS OFFICE S^MUMANNSTR.»7 D-4COO DÜSSELDORF I Telephone: (0211) 683346 ■ «&Mgr;&Igr;&kgr; (WTi) 6790871 - Telex: 8586513 cop d

HWENWNWAITE:
Dtpl.lng. W COHAUSZ · Dipl.-Ing. R KNAUF - OeUng. H a COHAUSZ - Dipl.-Ing. D. K WERNER ■ Dr. rar. net ft REOIES

06.06.1988 - 1 - We/Sr 48118G &bgr;

. Unex Corporation

120 Wesley street

South Hackensack

New Jersey 07606 / USA

Torque wrench

The innovation concerns a torque wrench for tightening or loosening a threaded connection between two parts, e.g. a bolt and nut.

Torque wrenches for threaded fasteners are known. A known torque wrench has a fluid-operated device arranged in a housing of the wrench, a drive device operable by the fluid-operated device, and an engagement device driven by the drive device and engaging the threaded fastener to tighten and loosen it. During tightening or loosening of the fastener, a reaction force is generated which tends to rotate the housing of the wrench in the opposite direction.

direction. It is known to have a «5

Torque wrenches with a reaction element which pushes against an adjacent object, for example ^an adjacent nut, a bolt, etc., in order to absorb this reaction force. The reaction elements are known in a variety of designs. For example, it is known from US-FS 38 68 872 to provide a washer

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to use between a mother or a bolt head and a flange and is thus used to absorb the reaction force. The disadvantage of this design is that the user to ensure good surface contact through the washer to obtain the required friction. For example, if the flange is not flat, the system described in this publication will not work. Also, the torsional forces applied to the bolt will remain the same as when using a standard torque wrench acting on an adjacent nut. Furthermore, the bolt will not be prevented from rotating in the same direction as the nut.

The innovation is based on the task of creating a simply constructed, easy-to-use, space-saving torque wrench with which a threaded connection can be easily made or loosened with little effort.

This task is solved according to the innovation by a torque wrench, by a power source, a first engagement means that can be brought into engagement with one of the connecting elements and a second engagement means which can be brought into engagement with the second connecting element, the engagement means being designed in such a way that when a force is applied by the force source of one of the engagement means, a connecting element rotates, while the other engagement means engages with the other Connecting element, causing tightening or loosening of the connection, is engaged.

According to a further advantageous feature of the invention, the second engagement means can absorb a reaction force which is present in the other part of the threaded connection during rotation of the one part

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generated, or even rotate the other part in a direction that is opposite to the direction of rotation of one part of the connecting element.

When the torque wrench is designed according to the features of the invention, it has a simple construction. At the same time, a reaction force generated during rotation of a part of a threaded connecting element is converted into reliably by the other part of the fastener without generating lateral loads or bending forces on the other part of the fastener. For example, if the torque wrench is used to tighten a bolt

TS arranged nut, the reaction force generated during tightening of the nut is absorbed by the bolt, or the bolt can be rotated in the opposite direction.

Further developments of the innovation emerge from the subclaims.

The innovation is explained in detail below using examples in conjunction with the drawing. They show:

Figure 1 is a front view of a torque wrench designed according to the innovation;

Figure 2 a side view of the torque wrench

Figure 1;

Figure 3 a side view of a torque wrench

in a different version; 35

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Figure 4 shows part of a torque wrench with

its drive means in a further embodiment;

Figures 5-7 Views of torque wrenches from other

Versions.

The torque wrench shown in Figure 1 has a housing 1. The torque wrench has a drive means (2) and a power source (2') arranged in the housing 1.

In the embodiment of Figures 1 and 2, the drive means 2 has bearing plates 3, each of which contains an opening and is arranged in such a way that a ratchet wheel 4 is rotatably mounted in the opening of the bearing plates 3. It is also possible to provide only one bearing plate 3. The bearing plates 3 are connected to the housing 1 via pins 5. More precisely, they are connected to additional plates 6 which are connected to the housing 1,

20) for example by welding. The drive means further has a drive member 7 which can be rotated about an axis 8. The drive rocker 7 carries a pawl 9 which engages with the ratchet wheel 4, for example with teeth or the like.

The power source 2', which provides the drive energy, has two fluid-operated, single-acting cylinder-piston units 10, 11, which are mounted on opposite sides of the drive arm 7 so

3Q are arranged so that they interact with the section arranged above the axis 8 of the drive rocker 7. Each cylinder-piston unit 10, 11 has a cylinder 10 formed by a part of the housing 1 and a piston 11 that can move back and forth in the cylinder 10.

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When tightening or loosening a threaded fastener, a reaction force is generated which tends to move the wrench in the opposite direction. In order to counteract or absorb this reaction force, the torque wrench designed according to the invention is provided with a reaction element 15. This reaction element 15 is elongated and is firmly connected at one end to the housing 1, for example by the pins 5 which connect the bearing plate 3 to the housing. In the embodiment shown, the torque wrench is used to tighten or loosen the screw nut 13 which is placed on the screw bolt 14.

TS The torque wrench ¹ is provided with two engagement means which engage with corresponding parts of the threaded connecting element. The first engagement means is an engagement opening 12 formed in the ratchet wheel into which the screw nut 13

2Q engages. The second engagement means is formed by the free end of the reaction element 15, which is arranged near a part of the connecting element, which is rotatably connected to the part to be tightened or loosened. In the embodiment shown, the free end of the reaction element 15 is located near the head of the bolt 14.

When tightening or loosening the screw nut 13 on the bolt 14, the ratchet wheel ⁴ is placed with its engagement opening 12 on the screw nut 13. The free end of the reaction element 15 is then brought close to the head of the bolt 14. When one of the cylinder-piston units 10, 11 is actuated, it rotates the drive rocker 7 together with the pawl 9 in one direction, whereby the pawl 9 rotates the ratchet wheel 4 in the rtl &ogr;&igr; ^hon Pi flhfunff d &Ggr; ¹ S fr ^* ^ar> ^ =&idigr;�Lgr; Ana &OHacgr; at· α nnopr^o A Ata

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nut 13 turns and screws onto bolt 14. The free end of reaction element 15 is firmly engaged with the head of bolt 14 so that it absorbs the reaction force generated during the rotation of nut 13. This eliminates all lateral loads and torsional forces that are normally exerted on such bolts by tools acting at a distance from the element to be tightened or loosened. When the other

to the cylinder-piston unit 10, 11 is actuated, it turns the drive rocker 7 in the opposite direction, causing the pawl 9 to jump over the ratchet wheel without turning it. The same process is repeated several times to completely tighten or loosen the screw nut 13.

The free end of the reaction element 15, which cooperates with the bolt 14, can be designed as a flat part that abuts flat against the bolt. Alternatively, it can be provided with an opening through which the

TO. Head of the bolt 14. It is understood that it can also be provided with other means which cooperate with the bolt 14.

Figure 3 shows a torque wrench according to another embodiment of the invention. In this embodiment, no additional reaction element is required. The second engagement means is provided in one of the bearing plates 3, namely the bearing plate 3 ¹ , which cooperates with a part of the threaded connecting element which is rotatably connected to a threaded part to be tightened or loosened. In the embodiment shown, the bearing plate 3 ¹ abuts with its free end flat against the head of the bolt 14 or has an opening through which the head of the bolt 1 ^J 4 extends. The shape of the opening in the bearing plate 3' can exactly match the shape of the head of the

' bolt 14 and can be hexagonal, square, with a keyway, etc. The same applies to the opening 12 which is provided in the free end of the reaction element 15 in the embodiment of the figure.

In the embodiment of Figure 3, no separate reaction element is provided and the width of the drive means 2 is thereby reduced. In addition, the torque wrench in this embodiment is a more self-contained unit.

If a stop is required against a stationary object located very far from the axis of the fastener to be tightened or loosened, another reaction element may be mounted on the torque wrench to abut against such a distant stationary object.

Figure 4 shows a power source 2' which is designed according to a further embodiment. While the hydraulic power source 2' in the embodiment according to Figure 1 has two single-acting cylinder-piston units 10, 11, the power source ²¹¹ according to Figure 4 has only one cylinder-piston unit 16, 17. This cylinder-piston unit 16, 17 is double-acting and has a cylinder 16 and a piston 17 which can move back and forth in it. During the displacement of the piston 17 in opposite directions in the cylinder 16, the head of the drive rocker 7 is displaced in the two corresponding directions via an engagement element 18.

On the other hand, the power source can also be equipped with only a single-acting cylinder-piston unit, which has a return spring. In this design, the cylinder-piston unit moves the

Drive shaft 7 in one direction to cause tightening or loosening, while the spring moves it in the opposite direction.

Figure 5 shows a further embodiment of the torque wrench according to the invention with a power source 20. The tool also has two drive means 21, 22 which are connected to the power source 20. The drive means 21, 22 have engagement means,

1U, for example, engagement openings 23, 24 which can be engaged with a screw nut and a bolt head. Both drive means can be provided with ratchet mechanisms. It is also possible for only one drive means to be provided with the ratchet mechanism

TS or both drive means have no ratchets at all. In the latter case, the tool must be reset after each stroke. In this design, the engagement opening of the other drive means holds the other part of the connecting element or even rotates it in an opposite direction when one part of the connecting element is rotated by the engagement means of one drive means.

Figure 6 shows a modification of the embodiment in figure 1. The second drive means 22' is detachably mounted, for example, on a part 25 which is connected to the power source 20 for providing energy via pins 26. The second drive means 22' can therefore be arranged on any side of the first drive means 21 in order to apply and release a bolt load.

Figure 7 shows yet another embodiment of a torque wrench. The tool has a power source 30, which can be designed as a pneumatic motor, hydraulic motor or electric motor. Drive means 31

T comprises a housing with a gear (not shown) therein. The drive means 31 is connected to engagement elements 32 and which each have a polygonal shape. The housing of the drive means 31 is firmly connected to the engagement element 32, while the gear (not shown) is firmly connected to the engagement element 33. 34 and 35 designate two sleeves which have polygonal inner openings. The sleeve 34 with the engagement element 33 forms the first engagement unit, while the sleeve 35 with the

T© engagement element 32 forms the second engagement unit. The inner shape of the sleeve 34 is such that it corresponds to the outer shape of the engagement element 33 and a bolt head 35. The inner shape of the socket 35 corresponds to the outer shape of the engagement element 32 and a

TS screw nut 37.

When the sleeve 34 connects the engaging element 33 to the bolt head 36 and the sleeve 35 connects the engaging element 33 to the nut 37, actuation of the power source 30 results in rotation of the bolt head 36 while the nut 37 remains stationary, or rotation of the nut 37 while the bolt head 33 remains stationary, or rotation of the nut 37 and the bolt head 36 in opposite directions.

In this design it is also possible for the bolt head and nut to be rotated without a motor and instead by manually applied force via a multiplier. On the other hand, the tool can be manufactured without a drive means 31 and instead with a direct connection of the power source 30 to engagement elements which directly engage the nut and bolt head. When the nut is rotated and the bolt unit remains stationary, the reaction force causes the rotation. In this case the entire unit rotates.

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It is to be understood that any of the elements described above, or two or more together, may also be usefully applied to other types of constructions other than the embodiments described above.

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List of reference symbols

1 Housing CVI Propulsion system CVl Power source CVI Power source 3 Bearing plate 4 Ratchet wheel 5 Pen 6 plate 7 Drive swing 8th axis 9 pawl 10 cylinder 11 Pistons 12 Access opening 13 Screw nut 14 bolt 15 Reaction element 16 cylinder 17 Pistons 18 Engagement element 20 Power source 21 Propulsion system 22 It 23 Access openings 24 It 25 Part 26 pencils 30 Power source 31 Propulsion system 32 Engagement element 33 The 34 sleeve 35 The 36 Bolt head 37 Screw nut

Claims (1)

COHAXJSZ & FLORACK PATENT ATTORNEY OFFICE SCHUMANNSTR.&THgr;7 D-4OOO DÜSSELDORF 1 Telephone: (Q2TI) 663346 - Fax: (0211) 6790871 - Telex: 8586513 cop d RAIENTANWAUE: CXpt-lng. Kl COHAUSZ - DipL-lng. R KNAUF - QpUng. HB COHAUSZ - DipWng. DH WERNER - Dt ret. naL B. REDIES 01.06.1988 - 11 - We/Sr 48118G C Protection claims 1. Torque wrench for tightening and loosening the connection of two parts in threaded engagement, characterized by a power source (2 ¹ ), a first engagement means which can be brought into engagement with one of the connecting elements and a second engagement means which can be brought into engagement with the second connecting element, wherein the engagement means are designed such that when a force is applied by the power source (2 ¹ ), one of the engagement means rotates a connecting element, while the other engagement means is in engagement with the other connecting element, causing the connection to be tightened or loosened. 2. Torque wrench according to claim 1, characterized in that the second engagement means is designed such that during the rotation of the one connecting element by the first engagement means, the other connecting element absorbs the reaction force generated by the rotation of the one connecting element. 3. Torque wrench according to claim 1, characterized in that the second engagement means is designed such that during the rotation of one connecting element in one direction, the second engagement means of the other connecting element in the opposite direction turns. U. Torque wrench according to one of the preceding claims, characterized in that it comprises a housing (1) and that the second engagement means is part of the housing (1). 5. Torque wrench according to one of claims 1 to 3, characterized in that it has a housing (1) and that the second engagement means ⁽¹ ) is connected to the housing (1). 6. Torque wrench according to one of the preceding claims, characterized in that it has a drive means (2) which is movably connected to the power source (2') and the engagement means and has a bearing plate (3), a ratchet wheel (4) which is rotatably supported by the bearing plate (3) and has an engagement means and comprises a drive rocker (7) which is in drive engagement with the power source (2') for rotating the ratchet wheel (4), the second engagement means being formed in the bearing plate (3). 7. Torque wrench according to one of claims 1 to 5, characterized in that it has a drive means (2) which is arranged for the transmission of force between the power source (2') and the engagement means and comprises a bearing plate (3), a ratchet wheel (4) which is rotatably mounted by the bearing plate (3) and which has an engagement means and a drive rocker (7) which is driven by the power source (2 ^' ) and which is connected to the ratchet wheel (4) for rotational entrainment, and that a ' « · I IHI *· I ¹ I* ·! (ff«l ·· - 13 - Reaction element (15) is provided which is connected to the housing (1) and to the second engagement means. 8. Torque wrench according to one of the preceding claims, characterized in that it comprises a drive means (2) which is force-connected to the power source ( ²¹ ) and the engagement means and has two drive means (21, 22) which are each connected to an engagement means. 9. Torque wrench according to claim 8, characterized in that each drive means (21, 22) comprises a pawl-ratchet mechanism with a corresponding engagement means. 10. Torque wrench according to claim 8, characterized in that one of the drive means comprises a pawl-ratchet mechanism with an engagement means. 11. Torque wrench according to one of the preceding claims, characterized in that the power source (2') comprises a motor with an axis and that the two engagement means are arranged coaxially to the motor.
30 12. Torque wrench according to claim 11, characterized in that the power source ( ²¹ ) is an electric motor. 13· Torque wrench according to claim 11, characterized in that it comprises a drive means with a housing and a gear arranged in the housing and connected to a motor, the housing being connected to one of the engagement means and the gear being connected to the other engagement means. 14. Torque wrench according to one of the preceding claims, characterized in that the power source (2 ¹ ) has a first axis, that the first engagement means has a second axis which is spaced in a predetermined direction from the first axis, and that the second engagement means has a third axis which is also spaced in a predetermined direction from the first axis. 15. Torque wrench according to one of the preceding claims, characterized in that the power source (2') has two single-acting cylinder-piston units (10, 11) which act on opposite sides of the drive rocker (7) for moving the same in opposite directions. 16. Torque wrench according to one of claims 1 to 14, characterized in that the power source ( ²¹ ) is a double-acting cylinder-piston unit (16, 17) which is arranged on one side of the drive rocker (7) for displacing the same in opposite directions. I · · ( t . Il M II · I ' II t » ti· ; ii·· - 15 - 17· Torque wrench according to one of claims 1 to 14, characterized in that the power source (2·) is a single-acting cylinder-piston unit (20) which acts on one side of the drive means (21, 22) and displaces them in one direction and is provided with a return spring for displacing the drive device in the opposite direction.