Abstract: The present disclosure discloses a door closer stopper, comprising a housing mounted around a door closer, a finger press block assembly and a stop assembly disposed in the housing. The housing is provided with a slot and an opening; The finger press block assembly comprises a press block and a rotary press block hinged to the slot of the housing, and a positioning mechanism limiting the rotary press block at a position propping a catch plate; The stop assembly comprises the catch plate with a central through hole to allow the pull rod of the door closer to extend therethrough, the catch plate is perpendicular to the pull rod and has a top end in a scope of movement of the rotary press block, the rotary press block can abut against the top end of the catch plate to make the catch plate incline when the rotary press block rotates to a certain position. The present disclosure is overly compact and reasonable in structure, simple and easy to operate, and practical, safe and reliable.

Abstract: The present invention relates to a door closer comprising a cylinder body and a telescopic rod, wherein a one-way air intake valve is provided in the cylinder body to take in air in one way in an internal cavity of the cylinder body when the door is opened. The internal cavity of the cylinder body is divided into two automatically pressurizeable and automatically compensatable air cavities. When the door is opened or closed, the air inside the internal cavity of the cylinder body flows cyclically in the two air cavities. The door closer ensures air substantially flows cyclically in a cylinder body, reduces pollution caused by dusts in air into and out of the cylinder body to the lubricant oil in the cylinder wall, guarantees the lubricating effect of the lubricant oil, enables the door closer to operate normally and effectively prolong the service life of the door closer.

Abstract: The present disclosure discloses a door closer stopper, comprising a housing mounted around a door closer, a finger press block assembly and a stop assembly disposed in the housing. The housing is provided with a slot and an opening; The finger press block assembly comprises a press block and a rotary press block hinged to the slot of the housing, and a positioning mechanism limiting the rotary press block at a position propping a catch plate; The stop assembly comprises the catch plate with a central through hole to allow the pull rod of the door closer to extend therethrough, the catch plate is perpendicular to the pull rod and has a top end in a scope of movement of the rotary press block, the rotary press block can abut against the top end of the catch plate to make the catch plate incline when the rotary press block rotates to a certain position. The present disclosure is overly compact and reasonable in structure, simple and easy to operate, and practical, safe and reliable.

Abstract: Core rod sections useable for production of finished optical fiber preforms are fabricated by inserting one or more core body pieces axially end-to-end inside a glass cylinder, thereby defining joints between adjacent ones of the inserted pieces. The cylinder is mounted with the contained core body pieces in the region of a furnace. The glass cylinder and core body pieces are heated together in the furnace, thereby elongating the cylinder and the core body pieces contained in the cylinder, and the cylinder collapses to form a finished core rod. Core rod sections are cut from the finished core rod at positions that coincide with the joints between the core body pieces. One or more of the cut core rod sections are useable for the production of optical fiber preforms.

Abstract: The present invention relates to a door closer, and particularly to an air pressure inner circulation-type automatic compensation control door closer, comprising a cylinder body and a telescopic rod, wherein a one-way air intake valve means is provided at the other end of the cylinder body to take in air in one way in an internal cavity of the cylinder body when the door is opened, at one end portion of the telescopic rod in the interior of the cylinder body is connected a regulating valve means wherein the gas in the cylinder body flows cyclically in the cavity of the cylinder body when the telescopic rod in a moving state, an inner cover sealing means is fixedly provided inside the end cap, and a large compression spring is provided in a cavity between the inner cover sealing means and the regulating valve means; the internal cavity of the cylinder body is divided into two automatically pressurizeable and automatically compensatable gas cavities through the inner cover sealing means, the regulating valve me

Abstract: Core rod sections useable for production of finished optical fiber preforms are fabricated by inserting one or more core body pieces axially end-to-end inside a glass cylinder, thereby defining joints between adjacent ones of the inserted pieces. The cylinder is mounted with the contained core body pieces in the region of a furnace. The glass cylinder and core body pieces are heated together in the furnace, thereby elongating the cylinder and the core body pieces contained in the cylinder, and the cylinder collapses to form a finished core rod. Core rod sections are cut from the finished core rod at positions that coincide with the joints between the core body pieces. One or more of the cut core rod sections are useable for the production of optical fiber preforms.

Abstract: An optical fiber preform is fabricated by inserting a number of core body pieces end-to-end inside a glass cylinder, wherein the pieces may have a cladding-to-core diameter (D/d) ratio within the range of one to four. The cylinder with the inserted core body pieces is mounted vertically on a furnace and heated so that the cylinder becomes elongated and its outside diameter collapses to form a core rod from which core rod sections with D/d ratios greater than five, can be cut. A soot overcladding is deposited on the circumference of a core rod section until the diameter of the deposited soot builds to a determined value. The core rod section with the deposited soot overcladding is consolidated to obtain a finished optical fiber preform. The preform preferably has a D/d ratio of about 15 or more, and an optical fiber may be drawn directly from the preform.

Abstract: An optical fiber preform is fabricated by inserting a number of core body pieces end-to-end inside a glass cylinder, wherein the pieces may have a cladding-to-core diameter (D/d) ratio within the range of one to four. The cylinder with the inserted core body pieces is mounted vertically on a furnace and heated so that the cylinder becomes elongated and its outside diameter collapses to form a core rod from which core rod sections with D/d ratios greater than five, can be cut. A soot overcladding is deposited on the circumference of a core rod section until the diameter of the deposited soot builds to a determined value. The core rod section with the deposited soot overcladding is consolidated to obtain a finished optical fiber preform. The preform preferably has a D/d ratio of about 15 or more, and an optical fiber may be drawn directly from the preform.

Abstract: Described herein is a method for making a depressed index cladding for the inner cladding of an optical fiber. The method involves making the depressed index cladding in two steps. The innermost portion of the inner cladding is produced using a soot method, thereby deriving the advantages of the soot method for the region of the cladding that carries the most optical power, then forming the remaining portion of the inner cladding layer using a rod-in-tube step. This method effectively marries the advantages and disadvantages of both methods.

Abstract: Described herein is a method for making a depressed index cladding for the inner cladding of an optical fiber. The method involves making the depressed index cladding in two steps. The innermost portion of the inner cladding is produced using a soot method, thereby deriving the advantages of the soot method for the region of the cladding that carries the most optical power, then forming the remaining portion of the inner cladding layer using a rod-in-tube step. This method effectively marries the advantages and disadvantages of both methods.

Abstract: A glass tube for use in an optical fiber preform is produced by applying a first soot on an end face of a starting member to form an elongated, porous cylindrical soot core having a first density, and applying a second soot including SiO2 on the periphery of the soot core to form a porous soot cladding having a second density greater than that of the soot core at the periphery of the core. The core and the cladding are later heated together at a temperature sufficient for sintering to form a core glass and a cladding glass. Because the soot core collapses at a greater rate than the soot cladding during sintering, the core glass separates or delaminates radially from the cladding glass. The core glass is then removed from the surrounding cladding glass, and the latter is treated to provide a high purity glass tube suitable for use as part of an optical fiber preform.

Abstract: The specification describes a VAD method for producing optical fiber preforms by depositing soot onto a solid core rod. The solid core rod preferably has a uniform composition, doped or undoped, suitable for the center core region of the preform. The primary cladding layer, and additional cladding layers if desired, are produced by depositing soot on the center core rod. The surface of the center core rod is treated with an etchant torch that traverses the center core rod in front of the soot deposition torch. This produces a clean interface between the core and primary cladding. This soot-on-center-core-rod method allows the production of sharp index profiles by reducing the diffusion of dopants into and out of the center core portion of the preform that occurs in soot-on-soot processes.

Abstract: The specification describes a VAD method for dynamically controlling the growth rate of both the core soot and the cladding soot in response to separate growth monitors.

Abstract: A super-large-effective-area (SLA) optical fiber that is suitable for communicating over a wide wavelength range and that, because of its large effective area, suppresses nonlinear effects that typically result from interaction between signal channels. The effective area, Aeff, of the SLA fiber of the present invention preferably is equal to or greater than approximately 80 ?m2 at a wavelength window around 1310 nm. The cutoff wavelength of the SLA fiber of the present invention preferably is less than 1310 nm. Thus, the SLA fiber of the present invention has a very large effective area and a very low cutoff wavelength. In accordance with the present invention, a variety of SLA fibers are provided that all have very large effective areas and desirable transmission properties. The large effective areas of the SLA fibers of the present invention enable nonlinear effects to be suppressed, as well as Stimulated Brillouin Scattering in analog transmission.

Abstract: Dynamically controlling the reaction temperature at the tip of a soot preform by controlling the flow of hydrogen gas to the core torch provides a wide latitude of control over the temperature range necessary to produce uniform composition of the preform.

Abstract: A super-large-effective-area (SLA) optical fiber that is suitable for communicating over a wide wavelength range and that, because of its large effective area, suppresses nonlinear effects that typically result from interaction between signal channels. The effective area, Aeff, of the SLA fiber of the present invention preferably is equal to or greater than approximately 80 &mgr;m2 at a wavelength window around 1310 nm. The cutoff wavelength of the SLA fiber of the present invention preferably is less than 1310 nm. Thus, the SLA fiber of the present invention has a very large effective area and a very low cutoff wavelength. In accordance with the present invention, a variety of SLA fibers are provided that all have very large effective areas and desirable transmission properties. The large effective areas of the SLA fibers of the present invention enable nonlinear effects to be suppressed, as well as Stimulated Brillouin Scattering in analog transmission.

Abstract: A glass tube for use in an optical fiber preform is produced by applying a first soot on an end face of a starting member to form an elongated, porous cylindrical soot core having a first density, and applying a second soot including SiO2 on the periphery of the soot core to form a porous soot cladding having a second density greater than that of the soot core at the periphery of the core. The core and the cladding are later heated together at a temperature sufficient for sintering to form a core glass and a cladding glass. Because the soot core collapses at a greater rate than the soot cladding during sintering, the core glass separates or delaminates radially from the cladding glass. The core glass is then removed from the surrounding cladding glass, and the latter is treated to provide a high purity glass tube suitable for use as part of an optical fiber preform.

Abstract: The specification describes a VAD method for producing optical fiber preforms by depositing soot onto a solid core rod. The solid core rod preferably has a uniform composition, doped or undoped, suitable for the center core region of the preform. The primary cladding layer, and additional cladding layers if desired, are produced by depositing soot on the center core rod. The surface of the center core rod is treated with an etchant torch that traverses the center core rod in front of the soot deposition torch. This produces a clean interface between the core and primary cladding. This soot-on-center-core-rod method allows the production of sharp index profiles by reducing the diffusion of dopants into and out of the center core portion of the preform that occurs in soot-on-soot processes.

Abstract: The specification describes a VAD method for dynamically controlling the growth rate of both the core soot and the cladding soot in response to separate growth monitors.

Abstract: The specification describes a VAD method for dynamically controlling the reaction temperature at the tip of a soot preform by controlling the flow of hydrogen gas to the core torch. This method provides a wide latitude of control over the temperature range necessary to produce uniform composition of the preform.