383 results about "Dowel" patented technology

A system for building a play area can include two or more panels, each of the two or more panels including a connector and at least one magnet positioned in the connector such that the at least one magnet is able to rotate, the at least one magnet including first and second magnets housed in respective first and second ends of the connector, the at least one magnet including at least one cylindrical magnet, the at least one cylindrical magnet being diametrically magnetized; and first and second dowels connected by the connector; each of the two or more panels being configured such that when at least one edge of each of the first and second panels are brought towards each other from any direction, the at least one magnet in each panel orientates such that a magnetic connection is formed between the two or more panels.

A system, e.g., for connecting a tie bar or other suspension member to a magnetic device in a magnetic track brake device, includes a bolt, a washer, and a taper dowel. The bolt includes a shaft having a first end and a second end, and a head attached to the first end. The washer is configured to fit about the shaft. The taper dowel is configured to fit about the shaft. The second end of the bolt shaft is configured to fit into a first aperture in the magnetic device, and the taper dowel, disposed about the shaft, is configured to fit within a second aperture in the suspension member. The second aperture corresponds in shape to an outer peripheral surface of the taper dowel, for the bolt to connect the suspension member with the magnetic device.

The gasoline engine generator fuel tank shell stamping die comprises a die body, a base, supporting columns, a hydraulic cylinder, a mistake-proofing structure and a waste collecting structure, the supporting columns are fixedly connected to the four corners of the bottom end of the base, a lower die is installed at the upper end of the base, a discharging port is formed in the middle of the interior of the lower die, and the hydraulic cylinder is fixedly connected with the lower die. A positioning pin is arranged on the upper surface of the lower mold, a heat conduction plate is arranged between the lower mold and the base, a refrigeration sheet is arranged at the bottom end of the heat conduction plate, the upper mold is arranged above the base, a cooling structure is arranged at the rear end of the lower mold, and the mistake-proof structure is arranged at the inner end of the lower mold. And the waste collecting structure is arranged at the bottom end of the base. By means of the structure, the problems that damageable parts of an existing stamping die are tedious to replace, waste is difficult to clean, and cooling efficiency is low can be solved, production efficiency is improved, the rejection rate is reduced, and the working environment is improved.

The utility model relates to a test device for testing a relationship between fractured rock mass damage and permeability change. A bidirectional loading unit comprises a sample underframe, a long-end fixing plate, a wide-end fixing plate, a lateral pressure transmission mechanism and a manual turbine loading device, the sample underframe is of an I-shaped structure; the two long-end fixing plates are oppositely fixed on the outer sides of the two ends of the sample underframe in the length direction; the two wide-end fixing plates are oppositely fixed on the front side and the rear side of the web plate on the sample underframe; the two lateral pressure transmission mechanisms are oppositely distributed left and right; the lateral pressure transmission mechanism comprises a lateral pressure plate, a main guide rod, a pressure bearing end and an auxiliary guide rod; the manual turbine loading device comprises two lateral counter-force plates, two lateral counter-force reinforcing rods, two manual turbine speed reducers, two flexible pressurizing plates and two pressure sensors; the vertical loading unit comprises an upper pressing plate, a dowel bar and a variable cross-section connector; and the permeation unit comprises two glass plates. The device can be used for testing the deformation, fracture, strength and permeation characteristics of the fractured rock mass sample under different confining pressures.

An electro-mechanical actuator for a valve can have a collar configured to envelope a portion of a commercially available liquid coupler. The collar can engage a region of the liquid coupler and a bias member can urge the collar to displace a movable member of the liquid coupler and thereby to break a coupling. A dowel can retain the collar against the force applied by the bias member and a tension member can, under threshold tension, retract the dowel, releasing the collar to move under influence of the bias member. Other valves have a gate element coupled with an armature to rotate the gate element under an electromagnetic field. The gate element can define a recess and a retainer can reside in the recess. As the gate element rotates, the retainer can align with a longitudinal segment of the recess and allow the gate element to displace longitudinally.

A yarn fluffing tool comprising: a dowel, the dowel comprising a first end and a second end; a first loop extending from the first end, the first loop having a generally smooth shape except for a first irregular portion where the first loop terminates at the first end and that first irregular portion has an irregular shape, the first loop is bent in a first direction away from the longitudinal directions of the dowel; a second loop extending from the first end and adjacent to the first loop, the second loop having a generally smooth shape except for a second irregular portion, where the second loop is basically a mirror image shape of the first loop; and where the first irregular portion and the second irregular portion overlap with each other.

Disclosed in the present invention is an improved connecting structure for a high-speed wiper arm, comprising a fixing base, a wiper blade, a connector, and a wiper arm. The windward surface of the connector is an inclined surface, and one end of the wiper arm is inserted into the connector and connected to the fixing base. A shaft is provided on a pair of side walls of the fixing base, two side walls of the end of the wiper arm inserted into the connector are respectively provided with a first opening slot, and the first opening slots are hinged to the shaft. The side wall of one side of the fixing base is provided with a second opening slot, and the top of the second opening slot is open. One side wall of the end of the wiper arm inserted into the connector is provided with a dowel pin, and when the wiper arm is assembled with the fixing base, the dowel pin is pressed into the second opening slot from the opening of the second opening slot. The present invention can improve the overall rigidity of the wiper arm while achieving an inclined-surface connector, thereby improving the overall stability of products.

The pump body transfer device of the oil delivery pump comprises a vehicle body, the vehicle body is of a hollow structure, trundles are connected to the bottom of the vehicle body, and a support is connected to the vehicle body. The bracket is connected with a plurality of layers of tracks, and each layer of track is in sliding fit with a laminate; a plurality of caulking grooves are formed in the shelf board, and positioning pins are connected to the shelf board on the side parts of the caulking grooves; the support comprises four stand columns, the four stand columns are connected to the four corners of the upper surface of the top plate, and one end of the support is connected with a second baffle. A plurality of sliding rods are connected to the side of the shelf board and are in sliding fit with the sliding grooves, and a handle is connected to one end of the shelf board. Compared with the prior art, worm blanks are inserted into the material placing holes to be transferred, and after the blanks on the top layer are taken and placed, a button on the switch is pressed down to control the electric push rod to stretch out and the material placing plate to turn upwards, so that the worm blanks on the lower layer are convenient to take and place.

The invention discloses an improved structure of a petroleum underground pitching sliding sleeve, and relates to the technical field of pitching sliding bushs.The improved structure comprises a pipeline, connectors are fixedly connected to the two ends of the pipeline, a plurality of clamping assemblies are arranged on the outer wall of the pipeline, a sliding sleeve is installed in the pipeline, a pitching ball is arranged in the sliding sleeve, and the clamping assemblies comprise pins; one end of the pin penetrates to the inner wall of the pipeline and is sleeved with a positioning block in a threaded mode. An elastic unlocking mechanism is composed of the button, the round pipe and the spring, under the normal working condition, the elastic force of the spring pushes the round pipe to abut against the interior of the pin, threaded connection and locking of the pin and the positioning block are guaranteed, thread loosening is prevented, when the sliding sleeve needs to be detached for overhaul, the button is pressed to compress the spring and drive the round pipe to retract, the locking state of the pin can be quickly relieved, and the service life of the pin is prolonged. The dowel can be drawn out by screwing out the positioning block, and cutting-free quick disassembly of the sliding sleeve is achieved.

A bezel assembly for mounting onto a back of a seat includes a bezel having an outer peripheral portion and an inner recess, and a deployable shelf rotatably mounted to the bezel and configured to rotate between stowed and deployed positions. The rotational attachments are friction hinges including a bracket and a dowel pin receivable in the shelf. One end of the dowel pin defines a plurality of circumferential grooves for seating one or more O-rings for providing a variable frictional interface for constraining rotation of the deployable shelf. In embodiments, the friction hinges eliminate the need for a separate mechanical latch for holding the deployable shelf in a stowed position.

The application discloses a positioning pin detection method and device, and relates to the technical field of automatic testing, and comprises the following steps: in response to a target test tool entering a test station, obtaining a to-be-detected image of a region where a positioning pin is located on the target test tool; determining at least one region-of-interest subgraph in the to-be-detected image according to standard coordinate information of the target test tool; and comparing the region-of-interest subgraph with a corresponding standard template image to obtain an existence state detection result of the positioning pin in the region-of-interest subgraph. The application realizes automatic detection without interrupting continuous production, guarantees high detection accuracy and efficiency, avoids a quality detection vacuum period between problem occurrence and the next manual inspection, and further prevents the risk of misjudgment or missed judgment of a large number of products due to inaccurate contact of a test probe, so that the test tool can be detected in a timely and accurate manner without interrupting production.

The utility model discloses a kind of steel mortise connecting nodes, belong to prefabricated building technical field, including two matching joint connections first embedded part and second embedded part;First embedded part, be configured with first vertical plate and first horizontal plate in inverted T shape connection;Second embedded part, be configured with second vertical plate and second horizontal plate that second vertical plate bottom end is outwardly stretched and fixedly connected in several type notches, several outwardly stretched dowels are provided on the two sides of second vertical plate side surface;First vertical plate matching insertion and fixedly connected in the several type notches of second vertical plate, and first horizontal plate and second horizontal plate are overlap fixedly connected between.Between the steel mortise connecting node provided by the utility model, node structure whole stability is good, compact structure, assembly is convenient and good safety.

The utility model relates to a secondary ejection structure of a plastic mold, and belongs to the technical field of molds. An ejector block is arranged below a lower ejector pin plate, a movable mold core is mounted on a movable mold plate, the top end of an ejector pin sequentially penetrates through an upper ejector pin plate, the movable mold plate and the movable mold core, the top end of a reset rod sequentially penetrates through the upper ejector pin plate and the movable mold plate, and a reset spring is arranged between the upper ejector pin plate and the movable mold plate; the top block is connected with the top end of a connecting rod through a connecting pin, and a fixing base is arranged at the bottom end of the connecting rod. When the mold is opened, the lower ejector plate drives the connecting rod to perform primary ejection, at the moment, the fixed seat is in contact with the movable mold plate, the locking mechanism unlocks the fixed seat, and then the lower ejector plate continuously drives the ejector pin to complete secondary ejection. The utility model aims to solve the problem that the appearance quality of a product is influenced due to deformation of the product caused by overlarge one-time ejection force.

The utility model relates to the technical field of positioning pins, in particular to an embedded type positioning pin mechanism for an automobile chassis structural part welding clamp, which comprises a connecting mechanism, a positioning pin is arranged at the bottom of the connecting mechanism, the connecting mechanism comprises a shell, an inner cavity is arranged at the bottom of the shell, and the positioning pin is arranged in the inner cavity. A first threaded hole is formed in the shell and communicates with the inner cavity, a connecting screw is in threaded connection with the interior of the first threaded hole, the positioning pin comprises a body, the top of the body is fixedly connected with a connecting block, the connecting block is located in the inner cavity, a second threaded hole is formed in the connecting block, and the second threaded hole communicates with the first threaded hole. The second threaded hole is located under the first threaded hole, and the bottom of the connecting screw is in threaded connection with the interior of the second threaded hole. The utility model provides a separable positioning pin mechanism, which can prevent the positioning pin from being too long to influence the welding of an automobile chassis structural member.

A system for building a play area comprising: two or more panels, each of the two or more panels comprising: a connector; and at least one magnet positioned in the connector such that the at least one magnet can rotate; wherein each of the two or more panels are configured such that when at least one edge of the first panel is brought towards at least one edge of the second panel from any direction, the at least one magnet in each panel orientate such that a magnetic connection is formed between the two or more panels; and wherein the at least one magnet comprises at least one cylindrical magnet, the at least one cylindrical magnet being diametrically magnetized; wherein the at least one magnet comprises: a first magnet housed in a first end of the connector; and a second magnet housed in a second end of the connector, wherein the connector connects a first dowel and a second dowel

The utility model relates to the technical field of tobacco curing, in particular to a moisture removal device for a cigar cooling room. Comprising a frame, moisture removal blades, a linkage rod, a rotating rod, a push rod motor base and a push rod motor, the moisture removal blades are assembled in the frame and inserted into moisture removal blade rotating shafts to be fixed through bolts, the rotating rod and the moisture removal blade rotating shafts are welded and formed, and the linkage rod and the rotating rod are connected through bolts; a push rod motor base is assembled on the surface of the frame and provided with a push rod motor, and the head of the push rod motor is connected with a linkage rod through a pin. The frame and the mounting, fixing and decorating landing edges are made of aluminum alloy, the dehumidifying blades are subjected to punch forming and surface plastic spraying treatment, and the cigar cooling room dehumidifying device is light in overall weight, resistant to corrosion, high in strength, long in service life when working in a high-humidity environment, capable of being automatically controlled and convenient to operate and use.

The utility model relates to the technical field of fabricated buildings, in particular to a fabricated building positioning steel bar adjusting tool. Comprising an abutting part, a dowel bar and a knocking part, one end of the dowel bar is connected with the abutting part, the other end of the dowel bar is connected with the knocking part, the surface of the end, away from the knocking part, of the abutting part can be attached to a to-be-adjusted reinforcing steel bar pre-buried in a module building, and the surface of the end, away from the abutting part, of the knocking part is a plane or an arc surface for knocking. When the tool is used, a worker can apply force on the knocking part, and the applied force is transmitted to a reinforcing steel bar to be adjusted through the dowel bar and the abutting part, so that the problems of low alignment precision, small operation space, unstable adjusting direction and the like when the reinforcing steel bar is adjusted by a traditional tool are solved; therefore, the problem that the building module cannot be located due to bending deformation of the steel bars in the butt joint process of the modular building is efficiently solved.

The invention relates to a cutting grinding machine (1) for grinding brake discs comprising a first circular grinding wheel and a second circular grinding wheel (12), axially facing and spaced apart from each other, so as to create a compartment (13) therebetween in which to position a brake disc to be ground, abrasive dowels (20) having a first abrasive surface (21) facing said compartment (13) and defined by a first portion of abrasive material (210) associated with a first longitudinal end of a dowel body (23) being mounted along the peripheral edge of each grinding wheel (11, 12). Each of said abrasive dowels (20) comprises a second abrasive surface (22) opposite to the first abrasive surface (21) and defined by a second portion of abrasive material (220) associated with a second longitudinal end of said dowel body (23). Each of said abrasive dowels (20 is removably fixed at its dowel body (23), either directly or indirectly, to the respective grinding wheel by connecting means configured to allow assembling the abrasive dowel in two alternative positions, one with the first abrasive surface (21) and one with a second abrasive surface (22) facing said compartment (13).

The invention relates to the field of forest carbon sink metering detection, and discloses a portable forest carbon sink rapid detection box. A power motor is fixedly connected to the inner side of the equipment box body, a two-way lead screw is rotatably connected to the front portion of the power motor, a sliding block is slidably connected to the outer side of the two-way lead screw, a dowel bar is rotatably connected to the upper portion of the sliding block, a rotating ring is rotatably connected to the upper portion of the dowel bar, and a supporting column is rotatably connected to the inner side of the rotating ring. The outer side of the supporting column is fixedly connected with an external thread, the outer side of the supporting column and the outer side of the external thread are slidably connected with a rotating limiting plate, and the rotating limiting plate is connected with a rotating limiting plate sliding groove. And water can be prevented from entering the equipment during raining detection. When the waterproof plate coincides with the contraction groove of the detection box, the power motor continuously rotates to enable the supporting column to ascend, and under the action of an external thread fixed to the outer side of the supporting column and a rotation limiting plate, the supporting column can rotate, so that the detection box can rotate, and the equipment can collect and detect the carbon sink amount in different directions.

Pressure unit (210) for a drive unit (150) for driving a web-shaped recording medium (120); wherein the pressure unit (210) comprises, - a pivoting arm (213) with a pressure roller (212), wherein the pivoting arm (213) is designed to pivot a main axis of rotation (211) away from or towards a drive roller (200) of the drive unit (150), so that a gap between the pressure roller (212) and the drive roller (200) is increased or decreased; - a fork (214) arranged on the swivel arm (213); - a camshaft (225) with a cam (222), wherein the camshaft (225) is designed to be rotated about a shaft axis of rotation (221), while the cam (222) is arranged in an opening of the fork (214), so that when the camshaft (225) is rotated, the pivot arm (213) is pivoted away from or towards the drive roller (200) of the drive unit (150) by the cam (222), depending on the direction of rotation; - the camshaft (225) or a lever (220) on the camshaft (225) has a first dowel pin (223) which extends radially away from the camshaft (225) at a first angular position, and a second dowel pin (223) which extends radially away from the camshaft (225) at a second angular position; - the pressure unit (210) comprises an end stop (224) for the first dowel pin (223) and for the second dowel pin (223) which is designed to limit the rotation of the camshaft (225) to angular positions between the first and the second angular position; - the end stop (224) is removable; - the camshaft (225) is designed to be rotated beyond the second angular position when the end stop (224) is removed; and - the pressure unit (210) is designed such that the cam (222) is moved out of the opening of the fork (214) when the camshaft (225) is rotated beyond the second angular position.

The utility model relates to the technical field of dies, in particular to a stamping die for scissor feet of a notebook computer. Comprising a base, a mounting frame and a stamping mechanism, the stamping mechanism comprises a lower die body, a moving seat, an upper die body, a first nut, a second nut, a penetrating sleeve and a descending device, and when the lower die body and the upper die body are replaced, the first nut and the second nut only need to be completely detached, and then the lower die body and the upper die body can be pulled out forwards to be detached; and through the arrangement of the T-shaped part, a positioning pin structure does not need to be arranged, replacement is more convenient compared with an existing mode that bolts and positioning pins are disassembled at the same time, and then the problems that when an upper die and a lower die of an existing scissor foot stamping die are replaced, multiple bolts and positioning pins need to be disassembled, the steps are tedious, and use is inconvenient can be solved.

The utility model discloses a combined adjustment zoom monocular microscopic device, and relates to the field of microscopic observation devices. The zoom lens assembly and the objective lens assembly are installed in the zoom sleeve, the compensation lens assembly and the fixed lens assembly are installed in a compensation sleeve, the sleeve is composed of the zoom sleeve, the compensation sleeve and a connecting cylinder, a linear groove is formed in the wall of the compensation sleeve in the length direction, a spiral sleeve is sleeved outside the compensation sleeve, and the spiral sleeve is sleeved outside the connecting cylinder. The wall of the spiral sleeve is provided with a spiral line groove which spirals regularly, a pin is inserted into the spiral line groove and the straight line groove and is connected with the compensating mirror assembly, and an outer cover is fixed outside the spiral sleeve; the wall of the zoom sleeve is provided with a linear groove along the length direction, a driving lever is inserted in the linear groove, and the tail end of the driving lever is in threaded connection with the zoom lens assembly. Compared with the prior art, the utility model can quickly adjust clear images and achieve the microscopic magnification effect; and the spiral line groove formed in the wall of the spiral sleeve is regularly spiral, so that the spiral sleeve is easy to manufacture and low in manufacturing cost.

The utility model relates to the technical field of sensors, in particular to a fiber bragg grating pressure sensor. Comprising an optical fiber, an elastic membrane, a dowel bar and a mounting seat, one end of the dowel bar is connected with the elastic membrane, and the other end of the dowel bar is in sliding connection with the mounting seat through a sliding block; the optical fiber is provided with a first grating section and a second grating section, one end of the first grating section is fixedly connected with the mounting seat, and the other end of the first grating section is fixedly connected with the sliding block; one end of the second grating section is fixedly connected with the sliding block, and the other end of the second grating section is fixedly connected with the mounting seat; and the elastic diaphragm generates axial deformation under external pressure to drive the dowel bar and the sliding block to move axially so as to drive the first grating section to perform stretching motion and simultaneously drive the second grating section to perform compression motion. According to the utility model, temperature compensation is realized by using a differential compensation principle, and errors caused by temperature change are offset, so that the measurement precision of the sensor is effectively improved.

A secondary battery cell includes a battery cell receptacle and an electrode assembly having multiple electrodes with each of the electrodes including a cathode tab and an anode tab. The electrode assembly is at least partially enclosed within the battery cell receptacle. The secondary battery cell includes a dowel extending through a tab dowel opening in at least one of the cathode tab or the anode tab on each of electrodes and a cap assembly having a cathode portion connecting the cathode tab on each of the electrodes to a negative terminal, an anode portion connecting the anode tab on each of the electrodes to a positive terminal, and a cap at least partially forming a battery enclosure for the electrode assembly with the battery cell receptacle. The dowel also forms a portion of a connection in one of the cathode portion or the anode portion.

The utility model discloses an airport concrete pavement dowel bar flat seam template which comprises fixing feet, a supporting frame body, a template body, a dowel bar and a dowel bar fixing piece, a bar piece bracket is welded to the rear side of a reserved through hole in the template, the pre-burying distance of the dowel bar is convenient to control, meanwhile, an easily-demoulded ring piece is arranged on the casting face side of the dowel bar, and the dowel bar fixing piece is fixed to the template body. The template at the dowel bar part can be easily removed, the damage of the concrete at the dowel bar part caused by the removal of the template is prevented, the overall quality of the concrete pavement is improved, and the dowel bar fixing part is arranged on the rear side of the template, so that the displacement of the rod piece caused by the influence of external factors such as mechanical equipment running and concrete vibration is prevented; the stability of the mounting position of the dowel bar in the concrete pouring period is ensured, the dowel bar is located at the position required by a design drawing from beginning to end, the dowel bar is stressed more uniformly in the runway operation period, and the anti-shearing force caused by resisting aircraft collision is enhanced.

The utility model relates to the technical field of engineering construction, in particular to a concrete panel false seam dowel bar mounting device which comprises a movable support and a pressing mechanism connected to the movable support through an adjusting mechanism. The downward pressing mechanism is used for pressing a dowel bar arranged on a concrete panel downwards so that the dowel bar can be pressed into the concrete panel, and the height of the downward pressing mechanism can be adjusted through up-down adjustment of the adjusting mechanism so that the lower end of the downward pressing mechanism can be kept in contact with the dowel bar. The downward pressing mechanism comprises a vibration motor, a connecting plate and a plurality of pressing rod assemblies arranged below the connecting plate at intervals, the movable support and the connecting plate stretch across a pavement formed by the concrete panel, and the pressing rod assemblies are arranged corresponding to the dowel bars; the vibration motor drives the pressing rod assembly to vibrate so as to press the dowel bar into the concrete panel in a vibration mode.

The utility model discloses a dry vacuum pump rotor positioning pin installation tool which comprises a tool body, the left end of the tool body is provided with a shaft end positioning part, the shaft end positioning part is arranged on a rotor shaft to be installed in a sleeved mode, the top face of the middle of the tool body is provided with a sliding groove, a sliding block is installed in the sliding groove in a sliding mode in the length direction, and the sliding block is connected with the tool body. A pin positioning installation opening is formed in the side, close to the shaft end positioning part, of the sliding block, the pin positioning installation opening is used for installing and fixing a positioning pin to be installed, a lead screw pair is arranged at the right end of the sliding groove and pushes the sliding block to move towards one side of the shaft end positioning part in the moving process, and a rocking handle is connected to the tail end of the lead screw pair. The technical problems that in the prior art, a positioning pin is inaccurate in installation and positioning, low in installation precision and inconvenient to operate are solved.

The utility model discloses an embedded type flat connection lock nail block which comprises a lock nail block body and an aluminum rod, the bottom of the aluminum rod is recessed inwards to form a groove, one side of the lock nail block body is provided with a flat connection insertion plate extending outwards horizontally, the flat connection insertion plate is provided with a lock catch protruding outwards, one end of the aluminum rod is provided with a lock hole, and the lock hole is provided with a groove. One ends of the aluminum rods are assembled from top to bottom and then are inserted into the lock holes through the lock catches to achieve connection. The lock nail block installed on the window profile can be more hidden, and the overall attractiveness is better.

Technologies for an optomechanical system include an intermediate plate having a top surface with multiple tapped holes arranged in a grid. A pair of dowel pin holes surround each tapped hole in a linear pattern. Multiple optical blocks are coupled to the intermediate plate using dowel pins positioned in the dowel pin holes and corresponding dowel pin holes defined in the bottom surface of the optical block. Each optical block includes multiple optical elements coupled to the top surface of the optical block with dowel pins. A cryostat may be coupled to the intermediate plate. A cryo-package assembly is mounted inside a cryo chamber of the cryostat. The cryo-package assembly includes a cryo device such as an ion trap covered by a machined copper lid. The lid includes a meandering passageway to allow for differential pumping in order to achieve ultra-high vacuum within the cryo-package assembly.

To provide a method capable of efficiently crushing a deck slab of a composite girder equipped with stud dowels. [Solution] A worker places an impulse-generating agent 15 on the girder portion 11. The impulse-generating agent 15 includes a pair of first impulse-generating agents 16 arranged on opposite sides of the stud dowel 4 in the bridge axis direction. The height of the charge center of the first impulse-generating agent 16 from the top surface of the steel main girder 3 is equal to or less than a first predetermined value. The distance between the first impulse-generating agent 16 and the stud dowel in the bridge axis direction is equal to or less than a second predetermined value. The worker detonates the impulse-generating agents 15 at approximately the same time.