367results about "Counting mechanisms/objects" patented technology

The invention relates to the technical field of sensors, and discloses a product counting method and system based on a production line, and the method comprises the steps: collecting an on-off signal when a target product passes through a sensor, building a sensor state array to record the on-off signal of the sensor, determining a sensor serial number corresponding to each sensor, and recording the on-off signal of the target product; and according to the sensor state array, judging whether each sensor sequentially acquires complete on-off signals according to the sensor serial number, when each sensor sequentially acquires the complete on-off signals according to the sensor serial number, determining that the target product is a single workpiece and counting, otherwise, detecting an abnormal sensor, and switching to a redundancy counting mode according to the abnormal sensor so as to count the target products. According to the invention, the method can improve the statistical counting precision of the production line, improves the anti-interference capability of the statistical counting of the production line, improves the counting stability, and reduces the maintenance and management cost of the production line.

The invention relates to the technical field of yield control, in particular to a neutron generator yield control method and system. The method comprises the following steps: establishing a polynomial model by using historical yield data to predict a target efficiency attenuation factor; dynamically determining neutron event boundaries in the pulse integral value and the pulse width two-dimensional characteristics based on the attenuation factor, and counting the neutron event boundaries; the yield deviation and the change rate are calculated, and when the deviation exceeds a threshold value, feedforward compensation is carried out on the target yield; and selecting a three-dimensional lookup table, an input deviation, a change rate and a current high voltage according to the interval to which the attenuation factor belongs, and cooperatively determining the adjustment amount of the ion source current and the accelerator high voltage. According to the scheme, the measurement and control problems caused by aging of the target piece can be solved, and the precision, the response speed and the long-term stability of yield control are improved.

The invention discloses an easy-open lid accurate counting device and method, the device comprises a chute, a photoelectric sensor and a gland assembly, and the gland assembly comprises a gland block, an optical axis, a spring and a pulse air source assembly; a directional separation spraying hole is formed in the bottom of the cover pressing block, when high-pressure gas conveyed by the pulse gas source assembly is sprayed out from the directional separation spraying hole, thrust towards the photoelectric sensor is applied to the to-be-counted easy-to-pull covers, and the easy-to-pull covers are pushed to enter a counting area one by one for counting; and the counter-acting force generated by gas injection drives the cover pressing block to move upwards along the optical axis, the spring is compressed, and therefore the adjacent clamped easy-to-pull covers are separated through the knocking force. According to the technical scheme, the directional separation spraying holes are matched with the pulse air source, the functions of air injection cover pushing and counter-acting force knocking separation are achieved at the same time, the clamping problem of the adjacent easy-to-pull covers is effectively solved, it is ensured that the easy-to-pull covers pass through the counting area one by one, and the counting precision is remarkably improved.

The invention discloses an automatic counting information synchronization method suitable for multiple types of cargo trays, and relates to the technical field of intelligent warehouse management, and the method comprises the following steps: inputting a single-piece standard weight parameter of a target cargo in an industrial touch screen, and binding the cargo information with a tray identifier through bar code recognition; goods to be measured are sequentially placed on the weighing platform provided with the four-point symmetrically-distributed weighing modules, the weighing modules collect total weight data of the goods in real time, and impact signals generated in the weighing process are dynamically filtered. According to the invention, the weighing precision is improved through structure optimization and dynamic filtering, automatic and accurate counting of the number of goods is realized in combination with a residual error correction algorithm, the security and completeness of data synchronization are guaranteed by adopting an encrypted two-dimensional code technology, real-time updating and traceable management of inventory information are realized, and the system is convenient to use. And the stability and the management efficiency of the intelligent warehousing system are comprehensively improved.

The invention relates to the technical field of image processing and extremely weak light imaging, and particularly provides a photon counting image reconstruction method and system, and the method comprises the steps: determining a target threshold value based on the adjustment of a dynamic adjustment coefficient under different illumination or gain conditions based on an initial threshold value; counting a first photon number of a single photon signal in the background image and a second photon number of the single photon signal in the signal image based on a target threshold, and generating noise photon number statistical distribution and signal photon number statistical distribution to determine a dynamic photon number processing interval; and performing time-space joint accumulation on the pixels conforming to the dynamic photon number processing interval, generating a two-dimensional photon accumulation matrix, and converting the two-dimensional photon accumulation matrix into a gray level image to form a single group of reconstructed gray level images. According to the method, real signals can be effectively extracted, the influence of dark noise, shot noise and readout noise is suppressed, zero noise detection is realized, and finally, the dynamic range, the signal-to-noise ratio and the stability of the image are remarkably improved through single-group image reconstruction and multi-group integration processing.

The invention relates to a photon pulse sequence atlas construction method, system and device based on a photon counting method, computer equipment and a readable storage medium. The method comprises the following steps: acquiring a plurality of photon counting data of a target insulation defect based on a photon counting method, constructing a phase resolution photon counting atlas based on the photon counting data, and splicing and sorting the phase resolution photon counting atlas to obtain a corresponding photon pulse sequence; the photon amplitude of each alternating current period can be obtained based on a photon pulse sequence built by a plurality of adjacent alternating currents, distribution characteristics of photon counting data can be obtained by combining a kernel density estimation formula, and a corresponding photon pulse sequence map can be built based on the distribution characteristics of the photon counting data. Therefore, a worker can directly distinguish the types of the insulation defects through the photon pulse sequence atlas.

The invention discloses a superfine pitch bonding wire chopper structure with a side wire incoming function and a using method thereof, and relates to the technical field of semiconductor packaging, the superfine pitch bonding wire chopper structure comprises a workbench, a lifting platform, a lifting counting mechanism, a switching mechanism, a pay-off pipe, a chopper mechanism and a smoke suction mechanism, and the lifting platform is slidably arranged between the workbench and a mounting frame; the lifting counting mechanism is arranged on the mounting frame, the switching mechanism is arranged on the lifting table, the chopper mechanism is arranged on the lifting table, and the smoke suction mechanism is arranged on the lifting table. By means of the arrangement mode that the lifting counting mechanism, the switching mechanism, the pay-off pipe, the chopper mechanism and the smoke suction mechanism are matched, after the designated number of times is reached, the chopper is switched through the switching mechanism, bonding quality reduction caused by abrasion is avoided, the switched chopper is cleaned, and the bonding quality is improved. And meanwhile, the smoke suction mechanism can suck cleaned impurities and possibly generated smoke, smoke and chippings are effectively collected, manual intervention is reduced in the whole process, and the production efficiency is improved.

The utility model discloses an infrared-based pedestrian flow in and out statistical device which comprises a fixed seat, an exhaust fan, a fixed plate, a slot, a mounting plate, a pyroelectric infrared sensor, a locking groove and a linkage seat. The beneficial effects of the utility model are that the device measures the movement of a human body through the pyroelectric infrared sensor, comprehensively judges and sends two messages of a person entering and a person exiting through the two probes, further realizes the statistics of people flow entering and exiting, and in the daily maintenance process of the device, if the device needs to be split, the device can be conveniently and rapidly maintained. When the mounting plate is mounted, the limiting rod slides in the limiting sliding groove for unlocking by pushing the mounting plate, the linkage seat slides under the action of the elastic force of the spring at the moment, the locking rod is separated from the locking groove, the mounting plate slides out of the inserting groove at the moment to achieve the quick splitting effect, and vice versa, the mounting plate is mounted; through the structure, a worker can quickly disassemble and assemble the pyroelectric infrared sensor, and the working efficiency of the device during daily maintenance is greatly improved.

Dose counter for a dispensing device, dispensing device, and associated dispensing assembly. This dose counter (100) for a dispensing device (20) for multiple doses of a product comprises a first graduated rotating element (110), a second graduated rotating element (120), and a transmission mechanism (130) between the first and second rotating elements. The first rotating element includes first reliefs (119A) and second reliefs (119B), which alternately cooperate with the transmission mechanism (130) so as to rotate the second rotating element by one graduation each time the first rotating element completes one full revolution. The graduation of the second rotating element comprises at least two identical adjacent digits.The dose counter (100) includes a priming cover (150), which is arranged to obscure a viewing window (302) for the graduations until the second rotating element (120) has been driven into rotation at least once. See Figure 4 for abbreviations.

The present application relates to flow detection device technical field, especially to a spur gear liquid flow detection device, the spur gear liquid flow detection device includes: gear assembly, including meshing transmission gear piece, the end face of gear piece is provided with magnet assembly, in the non-axis position of gear piece under the rotating state, the magnetic field formed by magnet assembly has the magnetic induction intensity of change; Detection assembly is arranged correspondingly with magnet assembly, to detect the magnetic induction intensity change of gear assembly under the rotating state, to obtain the accurate rotation number and / or angle of gear piece, when the liquid pushes the gear to rotate, the magnet assembly rotates with the gear, so that the magnetic induction intensity detected by the detection assembly is changed, to accurately judge the rotation condition of the gear, avoid the occurrence of the situation of missing detection, so as to improve the accuracy and accuracy of the spur gear liquid flow detection device for liquid flow detection.

The invention provides a display screen testing system and a display screen testing method.The display screen testing system comprises a display unit, a driving unit, a photoelectric detection unit and a counting unit, the display unit is provided with a display surface, the driving unit drives the display unit, and the photoelectric detection unit detects the display surface of the display unit; the counting unit is electrically connected with the photoelectric detection unit, when the driving unit drives the display unit to circularly start in a first time period, the photoelectric detection unit detects that the display surface is lightened and transmits a lightening signal to the counting unit, and the counting unit counts to obtain a first group of times; when the driving unit circularly drives the display unit to be turned off in a first time period, the photoelectric detection unit detects that the display surface is turned off and transmits a turn-off signal to the counting unit, the technical unit counts to obtain a second group of times, and whether the display function of the display unit is normal is judged according to whether the first group of times is equal to the second group of times.

This application discloses an automatic optical axis number identification device and method for a light curtain sensor. The device includes a main controller; a detection signal line connected to the detection port of the main controller and connected to a first reference potential through a first resistor; multiple cascaded axis control modules; each axis control module includes a shift unit, the clock terminal of each shift unit is connected to the main controller, the signal input terminal of the first-stage axis control module is connected to the main controller, the signal output terminal of the preceding-stage axis control module is connected to the signal input terminal of the following-stage axis control module; only the signal output terminal of the last-stage axis control module is connected to the detection signal line through an identification element. The main controller sends a valid level signal to the first-stage axis control module and outputs shift clock pulses to propagate the signal step by step. The number of optical axes is determined based on the number of clock pulses when the level of the detection port flips. This application achieves automatic optical axis number identification through cascaded shifting and a final-stage feedback mechanism, eliminating the need for manual configuration and effectively improving production efficiency and product reliability.

A method and apparatus for counting belted or bulk ammunition rounds. The modular ammunition counter includes a detachable electronics assembly, an ammunition guide for receiving the ammunition rounds, and a sensor module. The electronics assembly is configured to count the number of ammunition rounds that pass through the coupled ammunition guide. This method of ammunition round counting offers a significant improvement in speed and accuracy compared to manually counting the ammunition rounds by hand.

The application discloses a cam control method and device, equipment and medium, and relates to the field of mechanical automation control. The method is applied to an FPGA, and comprises the following steps: extracting a target parameter for representing the length of a target segment sub-path from a cam table, and updating a first counter for counting the displacement of a main shaft and a second counter for counting the displacement of a slave shaft; determining the target pulse number required to be output by the slave shaft by using the counting ratio relationship between the current two counters; if the main shaft has pulse input, updating the first counter, controlling the slave shaft to output the target pulse number of pulses, and updating the second counter; judging whether the pulse processing for the target parameter is completed based on the current counting of the two counters; if not, jumping to the step of determining the target pulse number required to be output by the slave shaft by using the counting ratio relationship between the current first counter and the current second counter. The application can reduce the resource consumption of the FPGA, and enable the slave shaft to quickly respond to the input of the main shaft.

The invention relates to a method of synchronizing a receiver initialization vector with a sender initialization vector when successively transmitting encrypted data packets from a sender to a receiver, wherein a key and an initialization vector are generated. The sender forms a sender sub-counter from the lowest M bits of a counter of the sender initialization vector, encrypts a message according to an encryption method, generates a data packet from the encrypted message and the sender sub-counter and transmits it, and increments the counter of the sender initialization vector. The receiver receives the data packet, extracts the sender sub-counter therefrom, forms a receiver sub-counter from the lowest M bits of a counter of the receiver initialization vector, replaces the lowest M bits of the counter of the receiver initialization vector by the sender sub-counter if the comparison results in the sender sub-counter being higher than the receiver sub-counter, and repeats the replacement and the incrementing of the counter value of the receiver initialization vector by 2 if the comparison results in the opposite, decrypts the message, and then increments the counter of the receiver initialization vector. M , decrypts the message, and then increments the counter of the receiver initialization vector.

The utility model discloses a fault frequency counting mechanism for ignition system testing, which belongs to the field of ignition fault testing and is characterized by comprising a body mechanism, a connecting mechanism is mounted at the outer end of the body mechanism, a detection mechanism is mounted at the upper end of the body mechanism, and the connecting mechanism comprises an assembly ring. The assembling ring is located at the outer end of the body mechanism, the inner end of the assembling ring is slidably connected with symmetrically-distributed clamping blocks, the clamping blocks are located at the outer end of the body mechanism, and clamping grooves are formed in the outer ends of the clamping blocks; by arranging the clamping blocks and the positioning rods, when the ignition device needs to be detached from the tester, only the pair of positioning rods needs to be pulled, the positioning blocks release positioning limitation with the clamping blocks, then the clamping blocks are taken out from the interior of the assembly ring at the outer end of the tester, and the ignition device and the tester can be conveniently detached and installed; and the mechanism is more convenient to count and test the number of faults.

The utility model relates to the technical field of counters, in particular to a counter pulse signal output connecting device which comprises a counter body, a fixing frame is installed at one end of the outer portion of the counter body, and an equipment box is installed at one end of the fixing frame. The shell is connected to the outside of the equipment box in a sliding mode, when the shell is completely connected to the outside of the equipment box, the output module and the connecting block are tightly attached to facilitate data transmission, and when a cross-shaped rotating disc rotates, a cylindrical block is extruded back through a limiting groove to slide in the cross-shaped rotating disc; when the cylindrical block moves, the limiting rod is synchronously extruded to slide in the fixing block, one end of the limiting rod extends to the outside of the equipment box, and when extending to the outside of the equipment box, one end of the limiting rod is synchronously connected into a limiting hole in the shell, so that the shell is fixed to the outside of the equipment box, and it is guaranteed that the output module and the connecting block are tightly attached; and disassembly and assembly are convenient, and maintenance is convenient.

The utility model provides an edible mushroom strain inoculator convenient for counting, which relates to the technical field of edible mushroom production and comprises an inoculation component, a tightening mechanism, a clamping piece and a supporting piece, the inoculation assembly comprises a strain storage cavity with a cylindrical appearance; according to the utility model, the clamping piece is arranged, and the clamping piece comprises the clamping plate; the clamping plates can be tightened through a specific tightening mechanism, so that the cultivation bag material can be stably clamped between the two groups of clamping plates; the slip phenomenon caused by sliding of cultivation bag materials or other unstable factors in the inoculation process can be effectively avoided, then it is ensured that inoculation operation can be accurately carried out on the cultivation bag materials, and the accuracy and reliability of inoculation work are greatly improved; the problems that most of existing strain inoculators are of a handheld structure, slipping possibly occurs when cylindrical cultivation bag materials are inoculated, and therefore inoculation work cannot be stably carried out are solved; and in addition, a strain receiver cannot count inoculation, so that the fruiting quality and yield can be influenced.

The invention relates to a linear and probabilistic logarithm counter. In one aspect, a dual scale counter circuit is provided, the dual scale counter circuit comprising: a counter logic unit to store a current counter value; a range determination logic to determine an operating range of the dual scale counter circuit based on the current counter value and a predetermined threshold; and a counter delta logic unit. The counter delta logic is to linearly increase the current counter value for delta events in response to the dual scale counter circuit operating within a linear range, and probabilistically increase the current counter value for delta events in response to the dual scale counter circuit operating within a probability range. The dual-scale counter circuit further includes a linear feedback shift register to generate a random binary bit sequence, a counter delta logic to generate a random binary bit sequence when the dual-scale counter circuit operates within a probability range, and a linear feedback shift register to generate a random binary bit sequence. It is determined whether to increase a current counter value for an incremental event based on the random bin sequence.

The invention relates to the technical field of plot seeding. The pneumatic type seed metering device is adopted, seeds can be stably adsorbed through negative-pressure seed suction during seed metering, seed falling is accelerated through positive-pressure seed unloading, and single-seed precise sowing is achieved; according to the invention, a seed-metering wheel type hole adopts an anti-blocking design, and a seed bin is provided with an anti-population towing device; the design of the inclined seed unloading plate can effectively solve the problem of miss-seeding phenomenon caused by less seed quantity of a single plot during plot breeding; according to the seed cleaning device, a traditional plug-in mounting type seed cleaning mode is optimally designed, a manual plug-in mounting mode is changed into an automatic driving mode, residual seeds are collected through negative pressure, the seed cleaning efficiency is greatly improved, and meanwhile, the residual seeds are recycled; the device is simple in overall structure, convenient to disassemble and assemble and easy to machine.

An automatic counting, checking and collecting device comprises a supporting frame, a material distributing disc is fixed to the supporting frame, a rotating disc is arranged on the material distributing disc, a plurality of fan-shaped grooves with the same size are formed in the rotating disc, a plurality of containing holes used for containing products are formed in the fan-shaped grooves, the containing holes penetrate through the fan-shaped grooves, and the rotating disc is arranged on the supporting frame. A fan-shaped blanking hole corresponding to the fan-shaped groove is formed in the material distributing disc, a driving assembly for driving the rotating disc to rotate is arranged below the rotating disc, and a camera for scanning the number of products is further arranged above the rotating disc; the driving motor drives the rotating disc to improve the counting efficiency and accuracy, the counting scheme that the circular rotating disc tool is combined with the groove is matched with the camera for automatic scanning confirmation, the problems that manual counting is prone to fatigue and inattention are effectively solved, it is ensured that the counting result is accurate, and meanwhile the labor cost and the labor intensity can be reduced.

The ammunition passing device comprises a base, an upper cover and a separated counter, two surrounding plates are vertically arranged at the front end and the rear end of the base in parallel, a first boss and a second boss are arranged on the portions, located on the upper surface of the base, of the inner sides of the surrounding plates at the front end and the rear end, and an ammunition belt channel is formed between the first boss and the second boss. The width of the ammunition belt channel is consistent with the length of a standard ammunition belt, when the ammunition belt of ammunition to be counted passes through the ammunition belt channel, the head and the tail of the ammunition pass through the upper surfaces of the first boss and the second boss respectively, the ammunition belt passes through the portion between the ammunition belt channels, an upper cover is detachably and horizontally arranged on the upper surfaces of the two surrounding plates, and a separated counter is arranged on the upper cover. According to the utility model, whether the ammunition meets the installation standard can be detected, so that the unqualified ammunition is prevented from entering the subsequent use link, and the safety and reliability of the ammunition are ensured.

This invention discloses an automatic construction device and method for ballastless track elevation pad blocks. The construction device includes a vehicle body, a control system mounted on the vehicle body, a material dispensing unit, a traveling device, a sensing device, a material flatcar, and a rotary motor. The material dispensing unit includes multiple dispensing components, each used to store elevation pad blocks of different thicknesses. A rotating component is located in the middle of the upper part of the vehicle body, and a rotary motor is installed inside the rotating component to drive its rotation. The multiple dispensing components are fixed to the outer periphery of the rotating component. This invention has a reasonable structure, simple operation, and modular design, enabling accurate and rapid distribution of specific elevation pad blocks of different specifications to corresponding sleepers. It avoids errors that occur with manual material dispensing, improves work efficiency without stopping the vehicle, reduces labor intensity, and automates the dispensing of elevation pad blocks during track laying and maintenance.

The application discloses a breath actuated inhaler. The inhaler comprises a main housing having a suction port at a distal end, a canister storing a drug solution and disposed axially within the main housing, and a force retention unit attached to the main housing and engaged with the canister, comprising an upper housing having an air intake structure disposed at a proximal end, the air inlet structure and the suction port form an air circulation path, so that the force maintaining unit responds to inhalation of a user to start the tank; wherein the air inlet structure comprises at least two holes with main openings, and the at least two holes are annularly arranged at the near end of the upper shell in an end-to-end connection mode, so that the main openings of all the holes cannot be completely covered when fingers are placed on the end face of the near end during inhalation of a user.

The invention provides a rotation turn number counting method and device, computer equipment and a storage medium, and is applied to target equipment, the target equipment comprises a gyroscope, and the target equipment is in a rotation process; the method comprises the following steps: determining an angle difference between a next integer angle corresponding to a target integer angle and the target integer angle; the target integer angle is an integer angle corresponding to the first rotation angle, and the next integer angle corresponding to the target integer angle is an integer angle corresponding to the second rotation angle; the second rotation angle is a rotation angle acquired after the first rotation angle is acquired through the gyroscope; accumulating the angle difference to obtain an accumulated angle difference; and when the accumulated angle difference reaches the first preset angle, adding one to the number of rotation turns of the target equipment. According to the technical scheme, the number of rotation turns in the rotation process is counted, and the accuracy of the number of rotation turns is guaranteed.

The invention discloses a rotating speed measuring device and method, and the method comprises the steps: enabling a PI input square wave signal to sequentially pass through a square wave shaping unit, a sampling and counting unit, a sliding window processing unit and a rotating speed calculation unit in an MCU microcontroller for processing, and obtaining a rotating speed measurement result; the square wave shaping unit is used for processing complementation shaping of PI input square wave signals and sending complementation shaping square waves to the sampling counting unit; the sampling counting unit judges a square wave counting value input into the sliding window processing unit according to comparison between an absolute value of a counting difference value of two adjacent square waves and an allowable error threshold value; the sliding window processing unit automatically adjusts the depth of the sliding window according to the input square wave count value; the sliding window processing unit sends the adjusted window depth to the rotating speed calculation unit, the rotating speed calculation unit calculates the rotating speed according to the adjusted window depth, the self-adaptive sliding window depth is adopted, different depth windows are adopted for different frequency signals for frequency calculation, and the operation complexity is reduced.

The utility model belongs to the technical field of coal mine underground drilling, and particularly relates to a coal mine underground drill rod counting device which comprises a supporting plate and a box body, the supporting plate is arranged above the box body, a plurality of insertion holes are formed in the supporting plate, a number plate is arranged at the position of each insertion hole, the interior of the box body is hollow, and the number plate is arranged in the box body. A plurality of inserting cylinders are vertically arranged in the box body in a penetrating mode, the number of the inserting cylinders is the same as that of the inserting holes, the inserting cylinders correspond to the inserting holes in a one-to-one mode, and four supporting rods are fixedly connected between the box body and the supporting plate and located at the four corners of the box body. By means of the device, the stability and safety of drill rod placement can be improved, workers can check and count conveniently, the counting process is visualized, errors caused by manual mental counting are reduced, the construction efficiency is improved, and the counting accuracy is guaranteed.

In general terms the aspects of the disclosed embodiments proposes a dose counter for registering a count of doses dispensed from an inhaler. The dose counter includes a counter ring including a circumferential drive feature. The dose counter also includes a worm comprising a shaft and a gear extending in a helical path about the axis of the shaft for driving the counter ring. The gear includes recesses uniformly distributed along the helical path. The dose counter further includes a cylindrical body including an engagement feature for driving the gear, the engagement feature extending in a helical or spiral path from the cylindrical body to engage the gear such that relative rotational movement between the cylindrical body and the worm rotates the worm about its shaft.

The utility model relates to the technical field of steel production, and discloses a steel billet shearing machine capable of adjusting shearing length, which comprises a conveying roller way, the conveying roller way comprises limiting frames on two sides and conveying rollers arranged between the limiting frames, and a plurality of roller way limiting components are arranged on the inner sides of the limiting frames and above the conveying rollers. A pressing fixing assembly is arranged above the conveying roller way, a pressing roller circle counting assembly is arranged at the tail end of the conveying roller way, and an attached laser cutting assembly is arranged behind the pressing roller circle counting assembly. The roller way limiting assemblies are arranged on the conveying rollers, so that steel billets with different widths can be limited during transportation, and the steel billets move forwards along a straight line; by arranging the downward pressing and fixing assembly, the steel billet can be fixed through downward pressing when reaching a specified position, so that the steel billet can be cut; by arranging the pressing roller circle counting assembly, when a steel billet passes through, the number of circles of the rotating lower pressing roller can be counted under the cooperation of a laser indicator and a laser counter, and therefore the shearing length can be adjusted according to needs.

In general terms the present invention proposes a dose counter for registering a count of doses dispensed from an inhaler. The dose counter comprises a counter ring comprising a circumferential drive feature. The dose counter also comprises a worm comprising a shaft and a gear extending in a helical path about the axis of the shaft for driving the counter ring. The gear comprises recesses uniformly distributed along the helical path. The dose counter further comprises a cylindrical body comprising an engagement feature for driving the gear, the engagement feature extending in a helical or spiral path from the cylindrical body to engage the gear such that relative rotational movement between the cylindrical body and the worm rotates the worm about its shaft.