Patent Grant
11167396
This disclosure relates generally to drilling apparatuses and, more particularly, to a drilling apparatus which continuously holds itself against an object surface while applying a driving force to drill holes therethrough.
A drill is a mechanical apparatus used to drive attached interchangeable drill bits into an object surface and produce a hole. A drill operator must apply a holding force on the drill toward the object surface and drive the tip of the drill bit against the object surface. This force must be consistently applied and adjusted as the drill bit's typically helical contours bore through the surface. However, manual drill operation is a tedious and physical arduous task which can quickly fatigue an operator, especially without proper ergonomics.
Self-holding devices, such as vacuum grippers described in U.S. Patent Publication No. 2020/0338695 (hereinafter '695), chiefly comprise a rigid base element and a loop-shaped vacuum seal element attached thereto. A vacuum generated between an object surface and the base element, but within the confines of the seal element, forces the vacuum gripper against the object surface. Although these devices work well to hold themselves against different object surfaces, they alone are unable to account for opposing forces between the drill and the surface, which can push the vacuum gripper away from the object surface. For example, a drill effectively pushes itself away from an object as it operates, so a holding force that emulates a human operator must adjust pressure accordingly while still applying a driving force on the drill against the object surface. A feedback mechanism may be utilized which can sense these forces and continuously adjust actuators that apply the holding force to prevent a drill from pushing itself away, but this mechanism would be prohibitively costly and may not ensure safe operation if, for example, a sensor or actuator fails. Furthermore, since vacuum gripper performance can vary when used across object surfaces of different materials, the issue of autonomously maintaining a reliable holding force on a drill is compounded.
Thus, there exists a need for a self-holding, self-driving drilling system that provides reliable, fail-proof, autonomous operation regardless of the type of object surface drilled.
Disclosed is a self-holding and self-driving drill system which incorporates a vacuum gripper base which has a drilling aperture, a sealing element, and an air extraction means. The sealing element comprises a peripheral seal which is disposed within an outer channel of the vacuum gripper base and an inner seal disposed within an inner channel around the drilling aperture. The activity of the air extraction means creates a low-pressure environment in a first volume contained by the sealing element, the vacuum gripper base, and an object surface. A delta pressure between the first volume and the immediate environment generates a holding force which causes the sealing element to conform to the object surface when the vacuum gripper base is pressed thereagainst.
The drilling system also incorporates a drilling assembly coupled to the vacuum gripper base. The drilling assembly comprises a drill apparatus positioned transverse to the drilling aperture. One or more piston tube(s) are transversely mounted to the vacuum gripper base in alignment with the housing. A linear pneumatic operation of the piston tube(s) causes the drill apparatus to move in a vertical direction with respect to the vacuum gripper base. One or more apertures in the base allow the first volume to be in fluid contact with a second volume contained by the piston tube(s).
The holding force is proportional to a first surface area of the first volume and effectively holds the self-drilling system to the object surface. Furthermore, a driving force is exerted upon the drilling apparatus by a low-pressure environment in the second volume. The driving force is equal to an opposing force exerted upon the drilling apparatus by the object surface during regular operation and is proportional to a second surface area of the second volume. The holding force is always greater than the driving force because the first surface area is greater than the second surface area, thus causing the drilling apparatus to be urged into the object surface without lifting the vacuum gripper base from the object surface no compromising the sealing element.
The embodiments of this invention are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:
Other features of the present embodiments will be apparent from the accompanying drawings and from the detailed description that follows.
Example embodiments, as described below, may be used to provide a self-holding drilling system. As used herein, ‘self-holding’ not only refers to the use of current vacuum gripper technology as described in U.S. Patent Publication No. 2020/0338695 (hereinafter '695), but also to the capacity of the drilling system described herein to urge a drilling apparatus thereof against an object surface without lifting the entire system off the object surface. Referring to
The vacuum gripper base 110 may be similar to the rigid base element of '695 (See marker 141 of FIG. 8 of '695), i.e., it incorporates a sealing element 112 which conforms to an object surface when the vacuum gripper base 110 is pressed thereagainst. Referring to
Referring to
In one embodiment, the air pump 102 provides a suctioning force that collects debris and other waste created by the drill apparatus. The suctioning force may remove debris through and/or around the drilling aperture 114 and direct the debris to a localized storage area.
Referring to
Referring to
The operation of the air pump 102 serves to extract air from a volume 118 that is contained by the vacuum gripper base 110, the sealing element 112, and an object surface (not shown). As a result of the low-pressure environment of volume 118, the vacuum gripper base 110 and the object surface exert a holding force 160 and an equal opposing force 165 upon one another that is proportional to the surface area of the volume 118. It is important to note that the surface area of the vacuum gripper base 110 is maximized by the use of a suction pad as shown which incorporates a grid-like structure.
The drilling assembly 120 comprises a housing 122 having sidewalls encompassing a drilling apparatus (not shown). The drilling apparatus accepts the typical variety of bits of various form factors, materials, and is centrally mounted over the drilling aperture 114. A downward force of the drilling apparatus would push the housing 122 upwards. The top of the housing 122 sidewalls incorporates a piston collar 124 which hold one or more piston tubes 130 against the vacuum gripper base 110. The piston tubes 130 are transversely mounted to the vacuum gripper base 110 and align vertically with the housing 122. Referring to
Referring back to
F=ΔP*A (Eq. 1).
A low-pressure environment in the volume 119 causes the piston tubes 130 to exert a driving force 150 (FD) upon the drilling apparatus and subsequently upon the object surface 140. FD is equal to an opposing force 155 (FD′) exerted upon the drilling apparatus by the object surface 140 during regular operation.
FD=FD′ (Eq. 2)
Based on Equation 1 above, driving force FD is proportional to the pressure differential (ΔP) between the volume 119 and the immediate environment 170 and the surface area A1 of the volume 119, as shown:
FD=ΔP*A1 (Eq. 3)
The volume 119 shares the same pressure differential of the volume 118. The ΔP between the volume 118 and the immediate environment causes the vacuum gripping base 110 to exert a holding force FH on the drilling system 100 against the object surface 140. Analogously to FD, FH is proportional to the ΔP between the volume 119 and the immediate environment 170 multiplied by the surface area A2 of the volume 119, as shown:
FH=ΔP*A2 (Eq. 4)
Since the surface area of the volume 119 (A2) is always significantly less than the surface area of the volume 118 (A1), FH is always greater than FD, which causes the drilling system 100 to remain held against the object surface 140 while maintaining an FD on the drilling apparatus that does not exceed the holding force FH, thus preventing the drilling system from lifting itself from the object surface 140.
All references including patents, patent applications and publications cited herein are incorporated herein by reference in their entirety and for all purposes to the same extent as if each individual publication or patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety for all purposes.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3240525 | Wood | Mar 1966 | A |
| 3506297 | Creskoff | Apr 1970 | A |
| 3640562 | Creskoff | Feb 1972 | A |
| D340256 | Ng | Oct 1993 | S |
| 5681022 | Rankin | Oct 1997 | A |
| Number | Date | Country |
|---|---|---|
| 1036586 | Jul 1966 | GB |
