A trepanning apparatus, including a shaft portion extending along a longitudinal axis; an annular cutter portion; and a connecting portion extending axially between the shaft portion and the cutter portion, the connecting portion including a pair of arms each having a front end connected to the cutter portion and a rear end connected to the shaft portion, the arms circumferentially spaced from one another about the longitudinal axis to provide diametrically opposed first and second openings, a first plug retaining surface defined by a first portion of the rearward end of the cutter portion having a first circumferential extent bounded by the front ends of the arms, and a second plug retaining surface defined by a second portion of the rearward end of the cutter portion having a second circumferential extent bounded by the front ends of the arms, the first circumferential extent greater than the second circumferential extent.

According to one aspect, a glass-free pre-impregnated material includes a polybenzimidazole (PBI) sheet and a partially cured resin encapsulating the PBI sheet. According to another aspect, a process of forming a glass-free pre-impregnated material includes encapsulating a PBI sheet within a resin and partially curing the resin to form the glass-free pre-impregnated material. According to yet another aspect, a printed circuit board comprises a glass-free dielectric layer that includes a PBI sheet encapsulated within a cured resin.

According to one aspect, a glass-free pre-impregnated material includes a polybenzimidazole (PBI) sheet and a partially cured resin encapsulating the PBI sheet. According to another aspect, a process of forming a glass-free pre-impregnated material includes encapsulating a PBI sheet within a resin and partially curing the resin to form the glass-free pre-impregnated material. According to yet another aspect, a printed circuit board comprises a glass-free dielectric layer that includes a PBI sheet encapsulated within a cured resin.

The present invention relates to a rechargeable hydraulic punching machine for a cable tray, in which a battery, a grip, a motor, a hydraulic cylinder, a punch, and a die are sequentially disposed along a straight line, a C-shaped head coupled to the head of the hydraulic cylinder is disposed, the punch and the die are disposed at both open ends of the C-shaped head, respectively, punch guards are disposed on a portion of the head spaced apart from both sides of the punch, the battery is configured to be charged and detachably attached, the motor transfers power to the hydraulic cylinder by using the power of the battery, and the hydraulic cylinder punches assembly holes of a cable tray by pushing the punch in the direction of the die by using hydraulic power based on the power of the motor.

An apparatus for perforating a panel of material comprising a driver assembly; a perforation assembly comprising a cutting edge for cutting the panel of material; an impacting surface moveable with respect to the cutting edge; and, means for holding the panel of material in a material plane between the cutting edge and the impacting surface, wherein the driver assembly is arranged to drive the cutting edge through the material plane into the impacting surface to cut the panel of material.

An apparatus for perforating a panel of material comprising a driver assembly; a perforation assembly comprising a cutting edge for cutting the panel of material; an impacting surface moveable with respect to the cutting edge; and, means for holding the panel of material in a material plane between the cutting edge and the impacting surface, wherein the driver assembly is arranged to drive the cutting edge through the material plane into the impacting surface to cut the panel of material.

Methods and apparatus for forming an aperture in a composite component are provided. For example, a method for forming an aperture in a ceramic matrix composite (CMC) component comprises, based on a final dimension of the aperture, selecting a tool having a tool size and a cutting surface; selecting an angle at which to cut the component with the tool; cutting a back surface of the component with the tool, the cutting surface positioned at the angle; repositioning the tool relative to the component; and cutting the aperture through to its final dimension. The tool may be a core drill with a diameter within a range of 60% to 90% of the aperture final dimension. The angle may be within a range of 10 to 60 with respect to the back surface. The aperture may be cut through to its final dimension from a front surface of the component.

A glass article (100) includes a core layer (102) formed from a core glass composition with a core coefficient of thermal expansion (CTE) and first (104) and second (106) cladding layers fused to first and second major surfaces of the core layer (102) and formed from a clad glass composition comprising a clad CTE. An aperture (120) extends through each of the core layer (102), the first cladding layer (104), and the second cladding layer (106). The clad CTE is less than the core CTE such that each of the first (104) and second (106) cladding layers is under a compressive stress and the core layer (102) is under a tensile stress. A flexural strength of the glass article (100) can be at least about 75 MPa. A peak load sustainable by the glass article (100) in a modified ring-on-ring test can be at most 96.5% less than a peak load sustainable by a reference glass article in the modified ring-on-ring test.

Disclosed herein is an apparatus for processing a substrate that forms a hole in a substrate while reducing a burr in the hole so that a module device can be inserted into the hole to reduce the thickness of a display device, and the display device using the apparatus. The apparatus for processing the substrate comprises a body configured to operably be rotatable, and a cylindrical cutting tip at an end of the body. The bottom surface of the cutting tip is in an acute angle with respect to a contact surface of the substrate to allow formation of a groove at the substrate.

Disclosed herein is an apparatus for processing a substrate that forms a hole in a substrate while reducing a burr in the hole so that a module device can be inserted into the hole to reduce the thickness of a display device, and the display device using the apparatus. The apparatus for processing the substrate comprises a body configured to operably be rotatable, and a cylindrical cutting tip at an end of the body. The bottom surface of the cutting tip is in an acute angle with respect to a contact surface of the substrate to allow formation of a groove at the substrate.