JPS5820757B2 - Nut runner with swivel head recoil rod - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates generally to nutrunners having recoil rods, and more particularly to pneumatically powered nutrunners having recoil rods that can rotate with a gear housing relative to a hand grip housing of an air motor.

Mass production of goods such as cars and trucks has encouraged the development of a wide range of assembly line tools.

The tools are generally pneumatically driven and provide power for rapidly regulated torque tightening of a wide variety of threading fasteners.

When tightening many fasteners, such as head bolts on internal combustion engines, the torque must be constant and not haphazard, so such tools have the ability to provide a constant torque. As a result, these tools have become widely accepted.

One disadvantage of such pneumatically powered tools is that the reaction torque generated by the tool (which is equal but opposite to the torque applied to the fastener) has traditionally been absorbed by the operator. It is.

When there are long shifts between work shifts, and in assembly departments where fasteners are tightened to high torque values, worker fatigue often prevents consistent torque application, resulting in tighter tightening. Further inspection and adjustment of the equipment may be necessary.

Additionally, workers often expect reaction torque from the tool and twist the tool at the end, which causes a torque that is often greater than the torque intended to be applied by the torque-adjusted tool to the fastener. and sometimes with dangerous consequences or damage to fasteners.

This difficulty was solved to some extent by adding a recoil bar.

This rod is attached to the tool, typically near a protrusion, so that it can be firmly stretched against any convenient surface of the product, such as a frame or perhaps an engine block.

The recoil bar transfers the recoil torque to the object against which it is firmly thrust, reducing the amount of recoil torque absorbed by the worker.

Furthermore, since the recoil rod is shaped so that it is firmly against one surface, the recoil rod is usually always firmly against this surface, and therefore the fasteners are repeatedly A highly consistent amount of torque will be applied.

An example of a recoil bar tool is shown in US Pat. No. 3,845,673.

However, the recoil rod solution to the problems of operator fatigue and non-constant torque application has one major drawback.

The recoil bar must be securely attached to the tool housing and must be oriented to function in the given application.

This inability to adjust generally impairs and precludes the use of a single tool for the assembly of various products having tensioning surfaces at different radial positions relative to the fastener.

The only effective solution to this problem is to have several tools in one work station, each with a recoil rod oriented in a different direction for each application, or to disassemble the tools.
The task was to reposition the recoil rod and reassemble the tool.

The former solution required an unprofitable expenditure of money, and the latter required an unprofitable expenditure of time.

Furthermore, if a series of different workpieces are to be torqued with a single tool, the torque rod may be adapted to each workpiece, but the operator will have different angles between the handle and the trigger. may be required to operate tools.

This makes his job more difficult and laborious.

The present invention relates to pneumatically powered rotary tools, commonly referred to herein as nutrunners, having a rotatable gear housing to which a reaction bar is fixed.

A rotatable housing or nosepiece surrounds a gear reduction unit that reduces the speed of the air-driven motor from a few thousand revolutions per minute to a few hundred revolutions per minute and conversely produces a proportional increase in torque.

The speed reducer is actually a torque generator. Because high r,
This is because the low torque input of pom is converted into high torque of low r, p, and m.

Therefore, this mechanism is the only thing that must be tightened to prevent the tool operator from experiencing recoil torque.

In other words, even though the recoil rod and gear housing are rotatable relative to the air motor housing and grip, the reduction gear to which the recoil rod and gear housing are attached is actually the source of the torque that must be absorbed, so the recoil The rod must be such that it transfers the recoil torque firmly toward the structure to which it is fixed, substantially eliminating the transmission of the recoil torque to the worker.

However, although the operator is subject to the reaction torque of the air motor itself, this torque is only a reaction torque (a relatively minor force) of the torque exerted by the high speed motor on the reducer. , which is a small force compared to the torque delivered to the fastener by a special speed reducer.

Therefore, as in conventional prior art devices,
While the reaction torque created by the reduction gear is transferred to the structure that is held tight by the reaction rod, the rotatable unit consisting of the reaction rod, reduction gear, and reduction gear housing of the present invention consistently reproduces accurately. The flexible tightening provides torque while making it easy to quickly move the recoil bar to new positions relative to the air motor housing and grip to accommodate different product dimensions and different geometries. Make it.

It is thus an object of the present invention to provide an air powered nutrunner having a reaction rod and a swivel joint located between the air motor and the speed reducer.

It is another object of the present invention to provide an air driven nutrunner having a rotatable reaction bar that facilitates its use on a variety of shapes of manufactured articles while providing accurate and consistent tightening torque.

Other objects and advantages will become apparent from the following detailed description of a preferred embodiment of a tool incorporating the present invention.

An air powered nut runner employing the present invention is generally designated by the numeral 10 in FIG.

Nutrunner 10 includes a housing 11 that surrounds and protects an air motor, not shown.

The housing includes a band grip 12 that is shaped to comfortably fit the driver's hand.

At the tip of the grip 12 there is an inlet fitting 13 to which a hose for supplying compressed air to the tool is attached.

Close to the junction of the housing 11 and the band grip 12 and located on the front side of the grip 12 is a push-button type trigger 14, which is conveniently operated by the operator's index finger.

When the trigger 14 is pressed, the valve connected to it (
(not shown) opens and the inlet fitting allows compressed air entering nut runner 10 via fitting 13 to proceed to an air motor (not shown) in housing 11, causing the air motor to rotate.

The nut runner 10 includes a gear type reduction gear within a cylindrical housing 15.

A reaction rod 16 is attached to surround the front periphery of the reducer housing 15.

The reaction rod 16 can be attached to the reducer housing by interlocking gears on the reaction rod 16, and the reducer housing 15 can be splined, polygonal (eg, hexagonal), etc.
It may form a matching surface or any convenient contour that prevents relative rotation between the two structures.

A collar 18 attached to the front end of the reducer housing 15 with a set screw 19 retains the reaction bar 16 on the reducer housing 15.

Alternatively, the reaction bar 16 itself may be retained on the reducer housing 15 by a set screw or other semi-permanent or permanent fixing means.

In the illustrated embodiment, removal of the collar 18 allows the operator to move the reaction bar 16 axially to remove it from spline engagement, and rotate the reaction bar to another position to remove it from spline engagement. It can be stored in a state of conformity.

An external force shaft 20 extends from the front end of the reducer housing 15 and terminates in a replaceable socket 21, typically a six-sided or twelve-sided socket that engages a tightened nut or clamping tool. Attachment can be a fixture.

A swivel assembly 25 is interposed between the air motor housing 11 and the reducer housing.

Swivel assembly 25 is shown most clearly in FIGS. 2 and 4.

The swivel assembly 25 includes an outer collar 26 and an inner collar 32.
and a plurality of ball bearings 31.

The periphery of the outer collar 26 consists of two different areas.

The end of the collar 26 adjacent the motor housing 11 includes an external thread 27 that mates with a mating internal thread 28 within the motor housing 11 .

The opposite end of the outer collar 26 includes a set of flattened surfaces 29 (see FIG. 4) that facilitate assembly and tightening of the outer collar 26 into the motor housing 11. Make it.

On the inner surface of the outer collar 26 is an annular semicircular groove 30 (in cross section).

Referring now to FIG. 3, the groove 30 serves as an outer retaining structure for a ball bearing race filled with a plurality of ball bearings 31.

The inner retaining structure of the ball bearing race is inner collar 3.
an annular semicircular groove 33 on the outer surface of 2;

A radially oriented threaded opening 34 in the outer collar 26 intersects a semicircular groove 30 in the outer collar 26.

Opening 34 is large enough to allow a plurality of ball bearings 31 to be loaded into the ball bearing race formed by semicircular grooves 30 and 33.

The threaded plug 35 has external threads that engage the threads in the threaded aperture 34 to tightly and semi-permanently close the threaded aperture 34 and a plurality of ball bearings 31 Reliably adjacent semicircular grooves 30 and 3
It should be kept within 1.

If it is desired to avoid the painstaking manipulation of a threaded stopper, the head of the stopper 35 may include an Allen or spline socket, or alternatively, so that the threaded stopper 35 can be conveniently removed. It is also possible to use a head shape that is not often used.

Inner collar 32 further includes a second annular groove 36 located between semicircular groove 33 and the proximal end of inner collar 32 .

The groove 36 has a square or rectangular cross section, and the groove 36 has a square or rectangular cross section.
Hold 7.

O-ring 37 provides a seal against the inner wall of outer collar 26 and provides a defined amount of resistance to rotation between the two collars 26 and 33.

The inner collar 32 also includes internal threads 38 on the end adjacent the reducer housing 15.

Threads 38 mesh and engage external threads 39 on the periphery of the cylindrical extension of reducer housing 15 .

Inner collar 32 further includes a plurality of pairs of flattened surfaces 40 (see FIG. 4) that facilitate assembly and tightening of inner collar 32 to reducer housing 15.

The reducer housing 15, which is secured to the inner collar 32 by an inner collar 32 and mating screws 38 and 39, is secured to the outer collar 32 by a plurality of ball bearings 31 loaded in aligned semicircular grooves 30 and 33. It is held by and movable relative to the collar 26 and the air motor.

Even conventional nutrunners that do not utilize the present invention typically have internal threads 28 on the air motor housing 11.
and external threads 39 on the reducer housing 15.

In such a device, the air motor housing 11 would be screwed directly into the reducer 15.

It is therefore clear that the present invention can be easily retrofitted to existing equipment by unscrewing the gear reducer from the air motor and screwing the swivel head of the present invention onto the air motor and gear reducer. It is.

An air motor (not shown) within the air motor housing 11 has an output shaft 45 extending forward of the motor housing 11 and centrally located therein.

The output shaft 45 is stabilized and centered by a ball bearing 46 mounted between the shaft 45 and a rigid structural member of the air motor housing 11.

Near the end of output shaft 45 is an external spline 47.

The outer spline 47 mates with a suitably sized inner spline 48 in the input shaft 49 which transfers power from the air motor output shaft 45 to the reducer man shaft 49.

Since the exhaust from air motors is often loud and noisy to workers, it is common to muffle the sound by passing the exhaust air through a vibration-stopping material 50.

The vibration damping material 50 may be any cellular or random fibrous material, such as a wire mesh, that does not deteriorate in use and in the atmosphere to which the tool 10 is exposed.

This material and air outlet is often located in the reducer housing 15 as shown, so that the exhaust takes its way to a vibration dampening material 50 and an outlet (not shown).

An annular passage 51 communicates between the air motor exhaust (not shown) and the vibration damping material 50.

The inner surfaces of collars 26 and 32 define the outer perimeter of passageway 51, and an O-ring seal 37 prevents air from escaping between the adjacent surfaces of collars 26 and 32.

The interior surface of the passageway 51 is defined by a generally cylindrical guide 52 which seats on an O-ring seal 53 located in an annular 54 in an annular structure within the air motor housing 15. Seal against seal.

The 0-IJ thong gear 53 thus retains the exhaust air within the passageway 51 and provides a convenient frictional attachment to one end of the cylindrical guide 52.

The opposite end of the cylindrical guide 52 also includes an annular groove 55 within which a second 0-IJ thong gurl 56 is positioned.

A second O-IJ thong 56 also retains the exhaust air within the passageway 51 and provides a convenient frictional attachment to the other end of the cylindrical guide 52.

Figures 5, 6 and 7 illustrate alternative embodiments of the tool.

In some applications, the frictional restraining force provided by the 0-IJ song gear 37 (see FIG. 2) may be insufficient to prevent rotation of the reducer housing 15 and reaction frame 16.

Still other applications may require the reaction frame 16 to be rotated repeatedly between several known positions.

FIG. 5 shows that the gearbox housing 15 is provided with a detented rotation relative to the air motor housing 11.
A spring biased detent arrangement is illustrated that includes a ball detent 60, a compression spring 61, and a threaded plug 62.

The outer collar 26 includes a radially disposed aperture 63 having an internal thread 64 along its length on its outer portion that mates with the thread on the threaded plug 62 .

Ball detent 60 fits within the unthreaded portion of opening 63 and is biased radially inwardly by compression spring 61.

The threaded plug 62 has an internal thread 6 in the radial opening 63.
4 and within the opening 63 a ball detent 60 and a spring 61.
is held.

The head of the threaded plug 62 may include an arelen or spline to facilitate positive assembly and simplified removal.

The stop or detent is in the form of a plurality of spaced indentations 65 on the inner collar 32 surrounding the outer surface of the inner collar 32 in a groove 66 adjacent to the semicircular groove 33. Take.

The longitudinal distance between the center line of the notch 65 and the groove 66 and the center line of the semicircular groove 33 of the inner collar 32 is of course the distance between the aperture 63
and the centerline of the semicircular groove 30 in the outer collar 26.

The indentations may be large or small in number and may be positioned at perhaps 45° intervals or at specific intervals to aid in the application of individual tools.

The depth and profile of the notch 65 as well as the strength of the compression spring 61 and the shape of the end of the ball detent 60 can be varied according to known practices to produce the desired detent strength.

In operation, the spring biased detent arrangement provides a positive detent against the reducer housing 15 each time the ball detent 60 falls into one of the notches 65 to prevent movement of the air motor housing 11. Restrict.

The rotational force between the air motor housing 11 and the reducer housing 15 is increased to push the ball detent 60 out of one of the notches 65 and the next notch is made between one housing and the other housing. It can be rotated to any position.

Although this alternative ball detent embodiment of the nutrunner 10 has been described as an alternative to utilizing an 0-IJ thong to provide friction between the two housings of the nutrunner 10, there is no variable frictional resistance. Nutrunner ball detent mechanism and 0-
It should be recognized that this in no way precludes the use of both the 'J' seal and the friction restraint configuration.

It will be appreciated that various other modifications and changes may be made in the above-described preferred embodiments of the invention without departing from the spirit and scope of the claims.

[Brief explanation of the drawing]

1 is a side perspective view of an air nut runner embodying the invention, and FIG. 2 is a partial side elevation cross-sectional view of the invention taken along line 2--2 of FIG. 3 is a front cross-sectional view of the invention taken along line 3-3 of FIG. 2, and FIG. 4 is an exploded perspective view of the invention illustrating the components of the swivel assembly; 5 is an inverted cross-sectional view of an alternative embodiment of the present invention similar to the view of FIG. 2, and FIG. 6 is a front cross-sectional view of the alternative embodiment of the present invention taken along line 6--6 of FIG. FIG. 7 is a perspective view of an exploded parts arrangement of an alternative embodiment of the present invention. 10... Nut runner, 11... Motor housing, 12... Hand grip, 13... Inlet mounting tool, 14... Trigger, 15... Reducer housing, 16... Recoil bar , 18...color, 19...
Set screw, 20... External force shaft, 21...
・Replaceable socket, 25...Swivel assembly, 2
6... Outer collar, 27... Male thread, 28... Female thread, 29... Flat surface, 30... Annular semicircular groove, 31... Ball bearing, 32...・Inner collar, 33...Annular semicircular groove, 34...Opening, 35
... Plug, 36... Second annular groove, 37... O-ring, 38... Inner thread, 40... Flat surface, 45... Output shaft, 46... ... ball bearing, 47 ... outer spline, 48 ... inner spline, 49 ... input shaft, 50 ... substance that stops vibration, 51 ... annular passage, 52 ... cylindrical Guide, 53... 0-ring seal, 54... annular groove, 55... annular groove, 56... 0-IJ song groove,
60...Ball detent, 61...Compression spring, 62
...Plug, 63...Opening, 64...Inner thread, 65
...Notch, 66...groove.

Claims (1)

[Scope of Claims] 1. A rotational power (generation) means having an output shaft, a first housing fixed to the rotational power means, an input shaft connected to the output shaft of the rotational power means, and a workpiece engaged with the input shaft. The required installations include a reducer having an output shaft connected to the gear, a second housing fixed to the reducer, a reaction bar fixed to the second housing, and the first and second housings. consisting of a combination of rotatable interconnects between
A tool in which the first housing and the rotating power means are rotatable relative to the second housing, the reaction rod fixed to the second housing, and the speed reducer. 2. The tool according to claim 1, wherein the rotating power (generating) means comprises an air-powered impeller motor. 3. The rotatable interconnect includes inner and outer interlocking collars, one of the collars being fixed to the first housing and the other of the collars being fixed to the second housing. fixed, the inner collar includes a circumferential semicircular groove on its outer surface, and the outer collar has a circumferential groove on its inner surface that is axially aligned with and circular therewith. 2. The tool of claim 1, comprising inner and outer collars including semicircular grooves around the circumference forming an annulus, and a plurality of ball bearings located within said annulus. 4. The tool of claim 1, wherein said rotatable interconnect includes means for frictionally resisting relative rotation between said first and said second housings. 5. The tool of claim 1, wherein said rotatable interconnect includes means for relative locking rotation between said first and said second housings. 6. The tool of claim 1, wherein the first housing includes a generally radially extending handgrip.