The present invention relates to shields for use with machine tools and the like to deflect materials ejected from associated work areas.
In various machining operations such as grinding, buffing, polishing, drilling, milling, etc., chips, broken tools, coolant or other debris, where used, are occasionally ejected from the work areas of the machines and can present a hazard to an operator thereof or other nearby personnel and/or equipment. In an attempt to minimize and hopefully prevent injuries and damage caused by such ejected material, and for other reasons, the Occupational Health and Safety Act of 1970 was enacted, and requires in part that one or more methods of machine guarding be provided to protect the operator and other employees in the machine area from hazards such as those created by point of operation, rotating parts, or flying chips.
Customarily, protection against flying chips and the like is provided by shields extending across the forward sides of the work areas. Such shields generally mount in or in close proximity to the work areas, and when moved aside either the mount or the shield itself often impedes access to the area. Further, upon change of the workpiece setup, the mount must often be repositioned to clear the new setup. Quick change mounts such as those having magnetic bases, while intended to alleviate the aforementioned problems, scratch and tend to be bumped off the machine mounting surface, sometimes into the work area itself. Thus, present day protective shields can be inconvenient to use and adjust, which may result in improper or even lack of use of such shields.
Accordingly, an apparatus is desired having the aforementioned advantages and solving and/or making improvements on the aforementioned disadvantages. A universal machine guard that is sufficiently adjustable that it can be used with a wide variety of machines in many different installations would clearly be advantageous.
An aspect of the present invention is to provide a machine guard assembly for a machine comprising a support, a connection subassembly connected to the support and a guard connected to the connection subassembly, with the guard having a transparent portion. The guard can be raised and lowered relative to the support by the connection subassembly.
Furthermore, the guard can be moved towards and away from the support by the connection subassembly and the guard can be rotated relative to the support. The guard can be raised to allow a person to use or attend to the machine and lowered to position the guard between the person and the machine to protect the person, with the guard allowing the person to view the machine through the transparent portion of the guard.
Another aspect of the present invention is to provide a method of safely using a machine for processing parts comprising positioning a machine guard assembly adjacent the machine, with the machine guard assembly comprising a support, a connection subassembly connected to the support and a guard connected to the connection subassembly. The guard has a transparent portion. The guard can be raised and lowered relative to the support by the connection subassembly, the guard can be moved towards and away from the support by the connection subassembly and the guard can be rotated relative to the support. The method also includes positioning the guard between a person using or attending to the machine and the machine, processing a part, and raising the guard to allow the person to have access to the part in the machine. The method further includes removing the part from the machine and lowering the guard to position the guard between the person and the machine.
Yet another aspect of the present invention is to provide a machine guard assembly comprising a vertically adjustable support member, a horizontally adjustable support member, a lifting arm and a transparent guard. The horizontally adjustable support member is rotatably connected to the vertically adjustable support member at a first end of the horizontally adjustable support member, with the horizontally adjustable support member being rotatable about a vertical axis. The lifting arm is rotatably connected to a second end of the horizontally adjustable support member, with the lifting arm being rotatable about a horizontal axis. The transparent guard is rotatably connected to the lifting arm. The guard can be moved in three dimensions and rotated about a vertical axis.
These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings.
For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as orientated in
The reference number 10 (
In the illustrated example, the machine 12 can be any machine that could use a guard in front of a machine during use to protect the user of the machine 12. For example, the machine 12 can be a lathe, a mill, a band saw or a drill press. However, this list is not considered to be exhaustive, as any number of machines may be used.
The illustrated support 14 for the machine guard assembly 10 can include a foot 22 for supporting the machine guard assembly 10 on a substantially flat surface 23. The illustrated foot 22 is not connected to the flat surface and allows a user of the machine guard assembly 10 to move the machine guard assembly 10 for use with any one of a plurality of machines in a workplace. Alternatively, the support 14 of the machine guard assembly 10 can be connected to a stand 25 for the machine 12 (
In the illustrated example, the support 14 for the machine guard assembly 10 includes a vertically adjustable support member 24. The vertically adjustable support member 24 includes a first telescoping tube 26 and a second telescoping tube 28. The first telescoping tube 26 is configured to slide within the second telescoping tube 28 to vertically adjust the vertically adjustable support member 24. In one embodiment, the first telescoping tube 26 and the second telescoping tube 28 include a plurality of openings 30 configured to have a pin 32 placed therethrough to lock the relative positions of the first telescoping tube 26 and the second telescoping tube 28. The pin 32 is removed from aligned openings 30 in the first telescoping tube 26 and the second telescoping tube 28 to allow the first telescoping tube 26 and the second telescoping tube 28 to be vertically adjusted. After the first telescoping tube 26 and the second telescoping tube 28 are in the desired position, the pin 32 is inserted into any pair of aligned openings 30 to lock the first telescoping tube 26 and the second telescoping tube 28 in position. In another embodiment, the first telescoping tube 26 and the second telescoping tube 28 have an internal motor for telescoping the first telescoping tube 26 and the second telescoping tube 28 to a desired position. However, it is contemplated that any means for vertically adjusting the vertically adjustable support member 24 and for locking the vertically adjustable support member 24 at a desired height can be used.
The illustrated connection subassembly 16 is rotatably connected to the support 14, thereby allowing the guard 18 to be rotated about the support 14. In the illustrated embodiment, the connection subassembly 16 includes a horizontally adjustable support member 34 rotatably connected to a top 44 of the support 14. The horizontally adjustable support member 34 is illustrated as being rotatable about a vertical axis. The horizontally adjustable support member 34 includes a first telescoping tube 36 and a second telescoping tube 38. The first telescoping tube 36 is configured to slide within the second telescoping tube 38 to vertically adjust the horizontally adjustable support member 34. In one embodiment, the first telescoping tube 36 and the second telescoping tube 38 include a plurality of openings 40 configured to have a pin 42 placed therethrough to lock the relative positions of the first telescoping tube 36 and the second telescoping tube 38. The pin 42 is removed from aligned openings 40 in the first telescoping tube 36 and the second telescoping tube 38 to allow the first telescoping tube 36 and the second telescoping tube 38 to be vertically adjusted. After the first telescoping tube 36 and the second telescoping tube 38 are in the desired position, the pin 42 is inserted into any pair of aligned openings 40 to lock the first telescoping tube 36 and the second telescoping tube 38 in position. In another embodiment, the first telescoping tube 36 and the second telescoping tube 38 have an internal motor for telescoping the first telescoping tube 36 and the second telescoping tube 38 to a desired position. However, it is contemplated that any means for horizontally adjusting the horizontally adjustable support member 34 and for locking the horizontally adjustable support member 34 at a desired length can be used.
In the illustrated example, the connection subassembly 16 further includes a lifting arm 46 connecting the guard 18 to the horizontally adjustable support member 34. The illustrated lifting arm 46 includes a four bar linkage 48 that rotates about an end of the horizontally adjustable support member 34. The four bar linkage 48 preferably includes a first vertical link 50, a second vertical link 52, a bottom link 54 and a top link 56. The four bar vertical linkage 48 preferably maintains a parallelogram shape as the lifting arm 46 is rotated about the end of the horizontally adjustable support member 34, with the first vertical link 50 and the second vertical link 52 maintaining a vertical orientation during rotation of the lifting arm 46. The lifting arm 46 preferably includes a vertical axis of rotation about the end of the horizontally adjustable support member 34 and a horizontal axis of rotation relative to the first vertical link 50.
The illustrated lifting arm 46 includes a counterweight 60 that counterweights the weight of the guard 18 to allow easy lifting and lowering of the guard 18. In the illustrated embodiment, the lifting arm 46 includes the counterweight 60 at a first end 62 thereof and the guard 18 at a second end 64 thereof. Therefore, the lifting arm 46 includes a first portion 66 on a first side of a pivot 68 of the top link about the first vertical link of the lifting arm 46 and a second portion 70 on a second side of the pivot 68 of the lifting arm 46. The counterweight 60 is on the first portion 66 and the guard 18 is on the second portion 70. The first portion 66 of the lifting arm 46 is substantially equal in weight to the second portion 70 of the lifting arm 46 and the guard 18 such that the guard 18 is easily lifted and lowered.
In the illustrated example, the lifting arm 46 includes a stop 72 extending from the bottom link 54 configured to abut against the top link 56 when the guard 18 is lowered to a predetermined position (see
The illustrated machine guard assembly 10 includes a first pivot point 100 between the vertical support member 24 and the horizontal support member 34 (
In the illustrated example, the second pivot point 102 includes a second locking mechanism 114 for rotatably locking the horizontal support member 34 to the four-bar linkage 48. The second locking mechanism 114 includes a C-ring connector 116 extending from the four-bar linkage 48. The C-ring connector 116 includes an aligned pair of openings for accepting a screw 118 extending upwardly from the horizontal support member 34. A nut 120 is screwed onto the screw 118 to compress the C-ring connector 116 between the nut 120 and the top of the horizontal support member 34 to rotatably lock the horizontal support member 34 to the four-bar linkage 48.
The illustrated third pivot point 104 includes a third locking mechanism 122 for rotatably locking the four-bar linkage 48 to the guard 18. The third locking mechanism 122 includes a C-ring connector 124 extending from the second vertical link 52 of the four-bar linkage 48. The C-ring connector 124 includes an aligned pair of openings for accepting a screw 126 extending upwardly from the guard 18. A nut 128 is screwed onto the screw 126 to compress the C-ring connector 124 between the nut 128 and the top of the guard 18 to rotatably lock the four-bar linkage 48 to the guard 18. The nuts 112, 120 and 128 could comprise wing-nuts for easily locking the first locking mechanism 106, the second locking mechanism 114 and the third locking mechanism 122. Although a particular first locking mechanism 106, second locking mechanism 114 and third locking mechanism 122 are illustrated, it is contemplated that any means could be employed to rotatably lock the vertical support member 24 to the horizontal support member 34, rotatably lock the horizontal support member 34 to the four-bar linkage 48 and rotatably lock the four-bar linkage 48 to the guard 18.
The illustrated guard 18 is rotatably connected to the lifting arm 46 of the connection subassembly 16 and is rotatable about a vertical axis. The guard 18 preferably includes the transparent portion 20 to allow a user of the machine guard assembly 10 to view the machine 12. The guard 18 preferably includes a plastic frame 80, with the transparent portion 20 comprising glass, a sheet of solid transparent resinous material sold under the trademark PLEXIGLASS®, or other similar materials. The guard 18 preferably includes a plurality of film layers placed over the transparent portion 20 that allow a user of the machine guard assembly 10 to remove one layer of film when the top layer of film becomes too dirty to thereby easily allow the user of the machine guard assembly 10 to once again clearly see through the transparent portion 20.
The reference numeral 10a (
The reference numeral 10b (
During use, as the lifting arm 46b is raised, a total distance of the cable 210 from the pin 212 to the fourth pulley 208 and back to the third pulley 206 decreases, thereby forcing the weight 204 downward in the weight housing tube 202. Likewise, as the lifting arm is lowered, the total distance of the cable 210 from the pin 212 to the fourth pulley 208 and back to the third pulley 206 increases, thereby forcing the weight 204 downward in the weight housing tube 202. The weight 204 acts as a counterweight to the guard 18b and the lifting arm 46a to easily allow the lifting arm 46a and the guard 18b to be easily raised and lowered.
The reference numeral 10c (
The reference numeral 10d (
It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention. For example, it is contemplated that the lifting arm 46 could be raised and lowered to position by any means. The lifting arm 46 could comprise a ratchet that will maintain the lifting arm 46 in a selected position that would reset when the lifting arm 46 is fully lifted to allow the guard to be lowered to a lowermost position. Moreover, it is understood that the actuator 74 could be used with the machine guard assembly on a support surface, connected to the support surface or connected to a stand for a machine. Furthermore, it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.