Patent Application
20070107936
1. Field Of The Invention
The present invention pertains to manually operated augers, and more particularly to apparatus that uses a straight line manual motion to rotate an auger.
2. Description Of The Related Art
Augers for drilling in ice and earth are well known and in widespread use. Augers typically include a center shaft. A helical band with a cutting edge at one end surrounds the center shaft. Rotating the center shaft causes the cutting edge to cut into the ice or earth. The helical band pushes the cut material away from the cutting edge to make a hole.
Some prior augers were manually driven. Manual augers were usually light weight, fairly inexpensive, and relatively easy to carry. An example of a prior manual auger, which uses a crank and gear mechanism, may be seen in U.S. Pat. No. 1,294,098. U.S. Pat. No. 4,817,735 shows a foot powered auger. Perhaps the classic example of prior manual augers is described in U.S. Pat. Nos. 2,393,282; 2,476,047; 3,051,253; 3,929,196; and 5,038,870. Those five patents each show an offset handle connected to an auger center shaft. A person grasped the handle with one hand and steadied the auger with the other hand. The person exerted his shoulder and arm muscles to produce a circular motion with his first hand, thus turning the handle and the auger.
When using a manual auger with an offset handle, multiple combinations of forces had to be generated by the person for each revolution of his hand. Specifically, a first force was generated to pull the hand in a first motion toward his body. Then the handle was forced across the front of the body in a second motion. Then, the person had to push the handle away from his body in a third motion. Finally, the person forced the handle across the front of his body in a fourth motion opposite the second motion. The process was repeated for each revolution of the handle and auger.
Because of the nature of ice and earth, considerable effort was required to drill holes with offset handle augers. Ergonomically, it was very difficult for most people to perform three of the four handle motions. The only motion that most people could complete with ease was the first motion of pulling the hand toward the body. That was a fairly natural motion during which most people could generate the maximum force with their arms and shoulder muscles. In general, younger, older, and other persons without adequate strength could not easily use the prior manual augers.
To ease the task of drilling in ice and earth, power driven augers have been developed. A common power source was a gasoline engine that connected to the auger center shaft. Some augers were powered from remote locations by suitable transmissions. U.S. Pat. Nos. 3,710,877; 3,828,861; and 4,116,284 illustrate different kinds of remote power sources and associated transmissions. Japan patent application number 1998000220506 teaches an auger powered by a motor and assembled to the end of a crane boom.
There are several disadvantages associated with power augers. In addition to being undesirably expensive, they are heavy and awkward to carry. The engines are subject to environmental standards, including emission controls and anti-noise ordinances. A related problem concerns the odors emitted from the engine, which is only an arm's length from the user's face. The noise and emissions make it an unpleasant task to drill holes with power augers. Moreover, power augers develop high torque, so safety is a major concern.
Thus, a need exists for improvements in ways to operate augers.
In accordance with the present invention, a dog-type recoil actuated auger is provided that requires a person to exert only straight line motions of the person's hand, arm, and shoulder to operate. This is accomplished by apparatus that includes a recoil mechanism that imparts unidirectional motion to an auger.
The auger has a shaft and a helical band around the shaft. A working end of the helical band at the auger shaft first end is sharpened. A second end of the auger shaft is connected to the recoil mechanism. The recoil mechanism is part of a recoil drive system that also includes a housing and a handle.
According to one aspect of the invention, the housing is comprised of a flat plate and first and second tubes all concentric with the auger shaft. The first and second tubes are joined by a transverse annular disk. The first tube receives and rotatably guides the auger shaft. The second tube receives a drive cup of the recoil mechanism. The drive cup has an annular wall, and an end wall that is fixed to the auger shaft. A washer separates the drive cup end wall from the housing annular disk. A collar on the auger shaft adjacent the first tube cooperates with the drive cup to capture the auger shaft to the recoil drive system housing. In the drive cup annular wall are a number of circumferentially spaced openings.
The recoil mechanism further comprises a cover that is secured to the housing plate. The cover contains a rope wheel that is rotatable about a cover pin. A rope is wound around the rope wheel. The rope terminates in a pull handle that is on the outside of the cover. A recoil spring biases the rope wheel to rotate in a first direction such that the rope pull handle is against the cover, which limits the rotation of the rope wheel in the first direction and establishes a wound position for the rope wheel. Manually pulling the rope pull handle rotates the rope wheel in a second direction and unwinds the rope from the rope wheel.
A pair of dogs are pivotable on associated rope wheel posts between working and retracted locations. When in their working locations, the dogs engage associated openings in the drive cup annular wall. The dogs are in their retracted positions when the rope wheel is at its wound position under the bias of the recoil spring and the rope pull handle is against the cover.
To pivot the dogs from their retracted locations to their working locations, they are designed to contact first surfaces of a cam that oscillates on the cover pin. An initial pull on the rope pull handle in a pull stroke rotates the rope wheel but does not turn the cam. After the rope wheel has rotated through a few degrees, the dogs contact the first surfaces of the stationary cam. Upon contacting the cam, the dogs pivot to their working locations under the impetus of the continually rotating rope wheel. Continued pulling on the rope causes the drive cup, cam, and auger shaft to rotate together with the rope wheel. At the end of the pull stroke, the rope is released, under control. The recoil spring turns the rope wheel, but initially not the cam, in the opposite direction and rewinds the rope onto the rope wheel. That action also causes the dogs to contact second surfaces on the stationary cam and pivot the dogs back to their retracted locations. The dogs therefore disengage from the cup wheel. From that point, the rope wheel, together with the cam, rotates back to its wound position, but without imparting any rotation to the auger shaft. The cycle is repeated as often as necessary until the auger has drilled the desired hole.
It is a feature of the invention that the auger may be disconnected from the recoil drive system. For that purpose, an output shaft is fixed to the drive cup end wall instead of the auger shaft. The free end of the output shaft is designed to selectively connect to and disconnect from the auger shaft. In that manner, the dog-type recoil actuated auger of the invention may be broken down for easily transportation.
The method and apparatus of the invention, using just straight line motions by a person, thus enables holes to be drilled in an ergonomically satisfactory way. The probability of unsuccessful operation is remote, even though he may not have adequate strength to generate forceful circular motions with his hand, arm, and shoulder.
Other advantages, benefits, and features of the invention will become apparent to those skilled in the art upon reading the detailed description of the invention and studying the drawings.
Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention, which may be embodied in other specific structure. The scope of the invention is defined in the claims appended hereto.
Looking first at
The particular dog-type recoil actuated auger 1 illustrated is comprised of an auger 3 connected to a manual recoil drive system 5. The auger 3 preferably has a sharpened end 6 opposite the recoil drive system 5. Operation of the recoil drive system causes rotation of the auger about a longitudinal axis 7 of the recoil actuated auger to drill into the ice or earth 9.
The auger 3 includes a shaft 11 around which is a helical band 13. The auger sharpened end 6 may be in the form of a knife 15.
In the preferred embodiment, the recoil drive system 5 is disconnectable from the auger 3. For that purpose, the auger shaft 11 has a socket 107 that receives an end 109 of a drive cup shaft 111, as will be explained shortly. A thumb screw 113 is used to hold the shafts 11 and 111 to each other and concentric to the longitudinal axis 7. In that manner, the dog-type recoil actuated auger 1 can be broken down for easy transportation.
The auger 3 is unidirectionally rotated by manual operation of the recoil drive system 5. Looking also at
The housing 17 includes a flat plate 21 and a pair of tubes 23 and 25. Both tubes 23 and 25 are concentric with the longitudinal axis 7. The two tubes are joined to each other by a transverse disk 27. The tube 25 rotatably guides the shaft 111.
A handle 28 is attached to the housing plate 21. According to one aspect of the invention, the handle 28 is constructed with a pair of small plates 30 welded or otherwise attached to the housing plate (
The recoil mechanism 19 is comprised of a cover 29 that is secured to the housing plate 21 by bolts and nuts 31. On the cover 29 is a cover pin 33 that is concentric with the longitudinal axis 7. A rope wheel 35 is rotatable on the cover pin 33. The rope wheel 35 has a hub 36 with a transverse end surface 80. In the hub 36 are two first diametrically opposed surfaces 38 that extend generally radially from and parallel to the longitudinal axis 7. The hub also has two second diametrically opposed surfaces 40 that extend generally radially from and parallel to the longitudinal axis. The rope wheel further has a peripheral groove 37 around which is wound a rope 39. One end of the rope 39 is fastened to the rope wheel. The other end of the rope terminates outside the cover at a pull handle 41. A recoil spring 43 has a first end hooked to the cover, as to a pilot 46. The recoil spring 43 also has a second end hooked to the rope wheel, such as to an annular rib 48. The recoil spring biases the rope wheel to rotate in a first direction, designated by arrow 44, toward a wound position. When the rope wheel is at its wound position, the rope is wound on the rope wheel and the pull handle 41 is against the cover. Pulling the pull handle rotates the rope wheel in a second direction, arrow 97, against the force of the recoil spring and unwinds the rope from the rope wheel groove 37.
On the rope wheel hub 36 are a pair of short posts 45. On each post 45 is a dog 47. Each dog 47 has first and second ends 49 and 51, respectively, on opposite sides of the post. Each dog also has an outside surface 53 and an inside surface 59 between the first and second ends 49 and 51, respectively. On the outside surface 53 is a first step 55 and a second step 57. The inside surface 59 has a portion 61 near the first end. The dogs are pivotable on the rope wheel posts 45 in the directions of arrows 62 and 64.
Also on the cover pin 33 is a cam 63. The particular cam 63 illustrated is formed with a flat disk 65 and four bent-over tabs 67A-67D. Each tab 67A-67D has a first surface 71 and a second surface 73. The rope wheel 35 and cam are held on the cover pin by a D-washer 77 and retainer ring 79. A compression spring 75 between the rope wheel and the cam disk 65 presses the cam disk against the D-washer 77. For clarity, a clearance is shown between the cam disk, dogs 47, and rope wheel end surface 80. In actuality, the clearance is minimal.
A drive cup 81 is also part of the recoil mechanism 19. The drive cup 81 has an annular wall 83 and an end wall 85. Preferably, the annular wall 83 has a flange 87 at its end opposite the end wall 85. In the annular wall are a number of circumferentially spaced openings 89. Fixed to the end wall is the drive shaft 111.
The drive cup 81 fits mostly inside the housing first tube 23 such that the openings 89 are transversely aligned with the dogs 47. A thrust washer 91 is interposed between the drive cup end wall 85 and the housing disk 27. A collar 93 with a set screw 95 on the drive shaft 111 cooperate with the drive cup end wall to retain the drive cup and auger 3 to the recoil drive system housing 17.
At the start of an operating cycle, the person holds the recoil drive system handle 28 with one and and the rope pull handle 41 with the other hand. He exerts a force on the rope pull handle by pulling it with a straight line motion 101 in a pull stroke. Doing so rotates the rope wheel 35 in the direction of arrow 97. Initially, there is sufficient friction between the D-washer 77 and the cam 63 such that the cam does not rotate with the rope wheel. Consequently, the rope wheel, together with the dogs 47, acquire the position relative to the cam shown in
Continued rotation of the rope wheel 35 causes the cam tabs 67A and 67C to pivot the dogs 47 in the direction of arrow 62,
When the dogs first ends 49 contact the rope wheel hub radial surfaces 38 no further pivoting of the dogs 47 relative to the rope wheel 35 is possible. Accordingly, continued rotation of the rope wheel under the impetus of the person continuing to pull the rope pull handle 41 forces the dogs, by way of their inside surface portions 99, to force the cam 63 to rotate in unison with the rope wheel. Simultaneously, the dogs inside surfaces at portions 115 force the drive cup 81 to rotate in unison with the rope wheel and thereby rotate the auger 3.
It is an important feature of the invention that the auger 3 is rotated about the longitudinal axis 7 using only the straight line motions 101 and 103 of the persons's arm, hand, and shoulder. The problems associated with the multiple circular motions required for prior manual augers with offset handles is therefore eliminated. Even persons of modest strength are capable of drilling holes using the present invention.
As mentioned previously, the auger 3 is disconnectable from the recoil drive system 5 by means of the socket 107 and thumb screw 113. It will be appreciated, of course, that the auger shaft 11 and the recoil mechanism drive shaft 111 may be a single integral piece, if desired.
In summary the results and advantages of holes in ice and earth can now be more fully realized. The dog-type recoil actuated auger 1 of the invention provides both an ergonomically sound way to manually operate an auger 3 as well as unidirectional rotation of the auger. This desireable result comes from using the combined functions of the recoil drive system 5. The handle 28 provides a good grip for a person's first hand. The recoil mechanism 19 rotates the auger in response to straight line motions 101 and 103 of the person's second hand, arm, and shoulder. The person exerts the straight line motions on the rope pull handle 41 to selectively wind and unwind the rope 39 on the rope wheel 35. The cam 63 cooperates with the dogs 47 on the rope wheel to pivot the dogs between working and retracted locations. When in their working locations, the dogs engage the drive cup 81 and force it to rotate with the rope wheel, thereby rotating the auger. In a return stroke, the dogs pivot out of engagement with the drive cup back to their retracted locations, thereby allowing the rope to rewind on the rope wheel without turning the auger.
It will also be recognized that in addition to the superior performance of the dog-type recoil actuated auger 1 of the invention, its construction is such as to to be of modest cost in relation to the benefits it provides. Its ergonomically superior design more than compensates for any increased cost relative to prior ergonomically unsatisfactory manual augers.
Thus, it is apparent that there has been provided, in accordance with the invention, a dog-type recoil actuated auger that fully satisfies the objects, aims, and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.
