Guard assembly for extending around a rotating shaft

A guard assembly is provided for extending around a rotating shaft extending between a driving device and a driven device. The guard assembly includes two plastic pliable covers bent to form two cylindrical housings. One cylindrical housing is slidable within the other and movable between a retracted and an extended position. A split ring adapter is secured to one of the devices and includes a series of lugs that project through circumferential openings in one of the cylindrical housings. Additionally, there is provided an end cap secured to one of the cylindrical housings opposite the adapter plate. There is also provided a series of elongated openings provided in each cylindrical housing and one or more fasteners projecting through respective pairs of openings so as to secure one cylindrical housing to the other and to permit one of the housings to slide with respect to the other when the fasteners are loosened.

FIELD OF THE INVENTION

The present invention relates to machine guards and more particularly to a guard assembly designed to extend around a rotating shaft extending between a driving device and a driven device.

BACKGROUND OF THE INVENTION

It is common to utilize a driving device, such as an electric motor, to drive a driven device, such as a pump. In these cases a drive shaft extends between the driving device and the driven device. Safety regulations, such as OSHA requirements, require that in certain commercial and industrial settings that a guard be placed around the rotating shaft so as to prevent loose clothing, such as ties and sleeves, from becoming entangled in the equipment.

In my earlier patent, U.S. Pat. No. 5,711,710 (the '710 patent), I disclosed a guard for extending around a rotating shaft. The '710 patent is expressly incorporated herein by reference. The coupling guard disclosed in this patent included a generally U-shaped cover sleeve formed from a flexible sheet of high density, high impact plastic that enclosed the rotating shaft coupling, thereby shielding the coupling so as to prevent body parts and objects from contacting the coupling. When installed, the cover sleeve is spaced from the coupling so as not to interfere with the rotation of shafts or the coupling interposed between the shafts. The cover sleeve is secured with a pair of brackets to a frame structure adjacent the rotating shaft and held stationary with respect to the rotating shaft. The cover sleeve defines two opposed end openings through which the rotating shafts extend.

While the guard assembly of the '710 patent has proven to be successful, the installation of this type of guard assemblies and others in the prior art can be time consuming and awkward. Thus, there is a need for a guard assembly for enclosing an area around a rotating shaft extending between a driving device and a driven device which is easy to install and which can be easily adjusted and secured around the rotating shaft so as to close the open area around the drive shaft.

SUMMARY OF THE INVENTION

The present invention entails a guard assembly for extending around a rotating drive shaft that extends between a driving device and a driven device. The guard assembly includes a first cover that is formed into a generally cylindrical shaped housing and a second cover that is formed into a generally cylindrical shaped housing. One of the cylindrical housings is telescopically contained or held within the other and movable therein between a retracted position and an extended position. An adapter is secured to one of the driving device or the driven device and is further secured to one of the cylindrical housings so as to support the guard assembly around the drive shaft.

In one embodiment, the cylindrical housings are provided with elongated slots and there is provided a series of threaded fasteners that extend through respective pairs of elongated slots. When the threaded fasteners are tightened, this secures one cylindrical housing to the other. When the threaded fasteners are loosened, one cylindrical housing can be moved fore and aft with respect to the other so as to adjust the effective length of the guard assembly.

Further, the present invention entails a guard assembly for extending around a drive shaft extending between a driving device and a driven device. The guard assembly includes a housing and a split adapter for connecting the housing to one of the driving device or driven device. The split adapter includes a frame structure that extends around a generally central opening defined by the frame structure for permitting the drive shaft to extend therethrough when the housing and adapter are installed between the driving device and the driven device. Further, the adapter includes one or more fastener openings for permitting a fastener to extend through the openings to connect to one of the driving or driven devices. In addition, the adapter includes an insert opening formed in at least an outer portion of the frame structure for permitting the drive shaft to pass therethrough when the adapter is being installed on one of the driving or driven devices.

The present invention also entails a method of forming a guard around a rotating drive shaft that extends between a driving device and a driven device. The method includes bending a first pliable cover around the rotating shaft to form a first cylindrical housing. Thereafter the first pliable cover is secured to an adapter that is, in turn, secured to one of the driving or driven devices. More particularly, the first pliable cover is secured to the adapter by projecting one or more lugs that form a part of the adapter into one or more lug openings formed in the first cylindrical housing. A second pliable cover is bent or shaped to form a second cylindrical housing. The method entails telescopically containing one of the cylindrical housings within the other such that one cylindrical housing can slide between a retracted position and an extended position within the other cylindrical housing. One cylindrical housing is secured to the other by utilizing one or more fasteners by extending each fastener through a pair of adjacently disposed elongated openings in the first and second housings. One of the cylindrical housings can slide within the other while one or more fasteners project through the elongated openings, and further one of the cylindrical housings can be secured with respect to the other by tightening one or more of the fasteners. Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings which are merely illustrative of such invention.

DESCRIPTION OF EXEMPLARY EMBODIMENT

With further reference to the drawings, particularlyFIG. 1, the guard assembly of the present invention is shown therein and indicated generally by the numeral10. Guard assembly10includes a housing structure indicated generally by the numeral20and an adapter, indicated generally by the numeral22. As seen inFIGS. 5 and 6, guard assembly10is designed to be interposed between two devices that are referred to herein as a driving device12and a driven device14. More particularly, the guard assembly10is designed to be disposed between these two devices such that the guard assembly extends around a drive shaft or drive shaft assembly indicated by the numeral16. Guard assembly10surrounds the drive shaft and generally prevents outside contact with the drive shaft16particularly while the same is rotating.

In practice, the driving device12and the driven device14may comprise various machines. However, in one typical application the driving device12comprises an electric motor while the driven device14comprises a pump. In this case, both the electric motor12and the pump14would include a stub drive shaft. Typically the stub drive shafts extending outwardly of the electric motor12of the pump14would be coupled together by a coupling device. Thus, in one embodiment, the drive shaft extending between the electric motor12and the pump14would include the respective stub shafts along with the coupling device. This assembly is simply referred to as a drive shaft.

Adapter22, as illustrated inFIG. 1, is designed to be secured to the face14A of the pump or driven device14. In addition, adapter22is designed to be secured to the housing20such that the housing is supported by the adapter22in cantilever fashion. That is, as seen inFIGS. 1-4, the housing20projects outwardly from and is supported by the adapter22. Details of how the adapter22and how it connects to and supports the housing20will be dealt with subsequently herein.

Turning to a discussion of the housing20, the housing20comprises a first cover indicated generally by the numeral30, and a second cover indicated generally by the numeral50. First and second covers30and50can be bent or shaped to form two cylindrical housing structures. As will be described subsequently herein, the two cylindrical housing structures are telescopically contained such that one of the housing structures can be moved back and forth with respect to the other between a retracted position (FIG. 3) and an extended position (FIG. 4).

First cover30, comprises a pliable sheet of material such as plastic or a high density polyurethane structure. Cover30can be flexed and bent and while the same may assume a sheet form the cover can be curved to form a cylindrical housing such as shown inFIGS. 1-4. Cover30includes opposed end portions. Each end portion includes a flange32that is disposed at an angle with respect to the main body of the cover30. Cover30, as shown inFIG. 3for example, assumes an operative mode. Here the opposed flanges32are secured together by bolt assemblies34. This forms a cylindrical housing having a cylindrical wall38which in turn forms an open interior space. Cylindrical wall38includes a number of openings. First, about one end portion of the cylindrical wall38there is provided a series of circumferentially spaced openings that are referred to as lug openings40. As will be appreciated from subsequent portions of this disclosure, these lug openings40facilitate securing the first cover30to the adapter22. In addition, cylindrical wall38includes a series of elongated openings42. In the case of the embodiment disclosed herein, as viewed inFIGS. 1-4, there is provided two sets of elongated openings42in the cylindrical wall38. Each set of elongated openings are axially spaced from each other and the openings of each set are circumferentially spaced around the cylindrical wall38.

Turning to the second cover50, the same is provided in a sheet form, and like the first cover30, is pliable or bendable such that the sheet form of the structure can be shaped into a cylindrical housing. Various materials can be used for both the first cover30and the second cover50. However, as noted above, it is contemplated that in one embodiment the material will comprise plastic or a high density polyurethane structure. Continuing to refer to the second cover50, when the same assumes an operative mode, as shown inFIGS. 3 and 4for example, the second cover forms a cylindrical wall52. Cylindrical wall52includes a series of elongated openings54. Elongated openings54formed in cylindrical wall52are spaced so as to register or align with the elongated openings42formed in the cylindrical wall38of the first cover30.

One end of cylindrical wall52is partially closed by an end cap56. In particular, end cap56comprises two opposed C sections that are secured to an end portion of the cylindrical wall52. The C sections of the end cap56define a central opening that permits the drive shaft16to extend therethrough.

In the case of the embodiment illustrated herein, the cylindrical housing formed by the second cover50is telescopically contained within the cylindrical housing formed by the first cover30. That is, the cylindrical wall52and the housing structure formed thereby can be moved back and forth within the cylindrical wall38of the first cover30. As illustrated inFIG. 3, the cylindrical housing formed by the second cover50is shown therein in a retracted position. From that position the cylindrical wall52can be extended outwardly as shown inFIG. 4. This essentially enables the guard assembly10to be adjusted in length such that it can be used in various applications where the length of the drive shaft16to be protected varies. When the first cover30and the second cover50assume a cylindrical configuration, the guard includes an axis and the elongated openings38and54formed in the first and second covers extend generally parallel to the axis.

As noted above, both cylindrical walls38and52have like elongated openings42and54. Some of these openings can function as ventilation openings. However, other elongated openings42and54can be utilized to secure the inner cylindrical housing to the outer cylindrical housing. There is provided a series of bolt assemblies58for accomplishing this function. As seen inFIGS. 3 and 4for example, a series of bolt assemblies58extend through aligned pairs of elongated openings42and54. When the guard assembly10is installed between an electric motor12and a pump14and when the length of the guard assembly has been properly adjusted, the bolt assemblies58can be tightened down so as to secure the inner cylindrical housing within the outer cylindrical housing. Thus, in this case the two cylindrical housings are stationed with respect to each other. However, during a period or time of adjustment where the inner cylindrical housing is moved back and forth with respect to the outer cylindrical housing, the bolt assembly58would assume a loosened state and therefore the elongated slots54of the inner cylindrical housing could move with respect to the elongated slots42of the outer cylindrical housing.

Turning to the adapter22, it should be noted that the adapter can be constructed of various materials. However, it is contemplated in one embodiment that the adapter22would be constructed of a strong and sturdy material that would have some flexibility. For example, the adapter22could be constructed of a plastic or a hard rubber. In any event, the adapter22is a split adapter in that it includes an opening formed in the frame structure thereof. In particular, the adapter22assumes a split ring configuration where the ring includes opposed ends22A and22B. SeeFIG. 1for example. Between ends22A and22B there is provided an opening and this is sometimes referred to as a shaft insert opening. That is, as illustrated inFIGS. 1 and 2, in installing the adapter22onto the driven device14an installer may be confronted with a drive shaft16that extends continuously from the driving device12to the driven device14. In that case, in order to properly mount the adapter22to the driven device14, the split ring frame structure will require being slightly flexed to form an opening between ends22A and22B that will permit the drive shaft16to pass therethrough. It further follows as viewed inFIGS. 1 and 2that the internal area of the adapter22is open to permit the drive shaft16to pass therethrough. To secure the adapter22to the driven device14, a series of bolts are extended through bolt openings in the frame or ring structure of the adapter and screwed into the flange or faceplate14A of the driven member.

To install the guard assembly10around a drive shaft16that extends between an electric motor12and a pump14, for example, where there is a continuous drive shaft16extending between the two, the adapter22would be bolted to the face or flange14A of the pump. Again, this would be accomplished as described above by simply flexing the frame structure or ring of the adapter22so as to form an opening between ends22A and22B sufficient for the drive shaft16to pass therethrough. Once the drive shaft16is passed through this opening, the frame or ring structure can be bolted to the pump14.

Next the first cover30is formed into a cylindrical housing by securing the flanges32together such as shown inFIG. 3. This is accomplished by extending bolt assemblies34through the openings formed in the respective flanges32. This, of course, forms a cylindrical housing. Prior to securing the flanges32together, one end portion of the first cover is placed around the adapter22. More particularly, the adapter22includes a series of circumferentially spaced lugs22C projecting outwardly therefrom. SeeFIGS. 1 and 2. These lugs22C are inserted into the lug openings40formed around one end portion of the cylindrical housing formed by the first cover30. Once the lugs22C have been extended through the lug openings40, the flanges32can then be secured together. Thus, it is seen that the cylindrical housing formed by the first cover30is supported in cantilevered fashion by the adapter22.

Now the second cover50can be bent or shaped to form a cylindrical housing. This is typically achieved by the hand of an installer. Once the second cover50has been shaped into a cylindrical housing, it is inserted into the end of the cylindrical housing formed by the first cover. This is illustrated inFIGS. 1 and 2. Next, bolt assemblies58can be connected in pairs of elongated openings54and42formed in the cylindrical walls38and52of the two cylindrical housings. Thereafter the inner cylindrical housing and its cylindrical wall52can be moved back and forth between retracted and extended positions to adjust the length of the guard assembly10to match the length of the drive shaft16extending between the driving device12and the driven device14.

From the foregoing discussions and specification, it is apparent that the guard assembly of the present invention has many advantages. One advantage is that the guard assembly is constructed of a strong material that will protect an isolate the drive shaft16. Further, the design of the guard assembly enables the same to be quickly and easily installed and adjusted by a single installer.

The present invention may, of course, be carried out in other specific ways than those herein set forth without departing from the scope and the essential characteristics of the invention. The present embodiments are therefore to be construed in all aspects as illustrative and not restrictive and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.