201242576 六、發明說明： 【發明所屬之技術領域】 本發明，是關於可共通地適用在裝有l.〇ml及1.8ml麻 醉液之二種卡匣的電動注射器。 【先前技術】 此種電動注射器所使用的卡匣，爲透明的玻璃製，且 於其中充塡有牙科用的局部麻醉注射液。此類卡匣，其注 射液的容量有1.8tnl及1.0ml二種，由於卡匣的內徑與外形 相同，所以長度會有不同。兩種無論哪一種卡匣，都是在 麻醉處理時，對於電動注射器，一般是將卡匣裝塡於卡匣 保持器，並將卡匣保持器裝著於電動注射器的連結接頭， 然後將兩頭注射針安裝於卡匣保持器的前端而與卡匣的內 部連通來使用。 電動注射器，具備有：爲了使來自卡匣的麻醉液通過 注射針並排出，而用來推壓卡匣之柱塞橡膠栓的推壓棒、 以及用以使推壓棒前進移動的作動裝置。此種作動裝置， 一般是包含：藉由包含馬達及減速機之驅動單元的動力傳 達而旋轉的小齒輪、及在與小齒輪的齒合下用以使推壓棒 進行直線性移動之在推壓棒形成的齒條。爲了使來自被裝 塡於卡匣保持器之卡匣中的麻醉液，可通過注射針並排出 ，所以推壓棒的直線移動，必須進行相當於卡匣之麻醉液 容納長度的距離。推壓棒的直線移動距離，是以推壓棒的 特定部分將微動開關予以關閉（Off )，藉此停止馬達的旋 -5- 201242576 轉來予以限制。注射液排出後，將卡匣保持器從連結接頭 卸下阻斷驅動單元的動力傳達而使小齒輪處於可空轉狀態 ，以手將推壓棒朝注射器本體內推回同樣的距離。在此過 程中，微動開關，係處於推壓棒的外面而呈開啓（on)的 狀態》 目前本案申請人販賣於牙科醫療的卡匣式電動注射器 ，由於裝有麻醉液1.0ml及1.8m之卡匣的長度不同，因而 用以使麻醉液排出而推壓卡匣的柱塞橡膠栓的推壓距離不 同，所以裝設於電動注射器的卡匣保持器以及包含推壓棒 都是各別分開專用的。隨著電動注射器的普及，在牙科業 界期望有可共通地使用於1.0ml及1.8 ml麻醉液卡匣的電動 注射器的問世。若以至今之電動注射器的構成爲念來思考 此問題時，當然也要使卡匣保持器能夠共用在裝有1.0ml 及1.8xnl麻醉液的卡匣，不過對於1.0ml及1.8ml之卡匣，若 確立共通之推壓棒的前進終端位置，那對於1.8ml的卡匣 而言，就必須使推壓棒的開始位置縮入相當於卡匣長度上 之差異的距離量。如此一來的話，電動注射器的推壓棒， 由於在推壓1.8ml卡匣之柱塞橡膠栓時必須要有其足夠的 長度，所以推壓棒就得朝後方延伸一相當於卡匣長度上之 差異的距離量，因此必須使電動注射器本體可往後方突出 。基於如此思考所硏發的發明，係如專利文獻1所揭示。 於該專利文獻1中，也記載有：不論在哪一種卡匣的設定 位置上，皆以一定壓力將推壓棒擋接於卡匣的柱塞橡膠栓 。然而，於專利文獻1所揭示之發明的構成，在朝向以緊 -6- 201242576 緻的（compact )電動注射器爲目標上並未必是理想的發 明。 〔專利文獻1〕日本特許第4 1 98435號專利說明書》 【發明內容】 〔發明所欲解決之問題〕 本發明的目的，是在於提供一種使卡匣保持器以可以 共用於裝有1.0ml及1.8ml麻醉液卡匣之方式而構成’且利 用推壓1.0ml卡匣之柱塞橡膠栓所必要之長度的推壓棒， 也可以用來推壓1.8 ml卡匣之柱塞橡膠栓之可兼用二種裝 有牙科用麻醉液之卡匣的電動注射器。 〔發明解決問題之技術手段〕 本發明之上述目的，是藉由提供一種可兼用二種裝有 牙科用麻醉液之卡匣的電動注射器而達成，其是藉由連結 接頭將已裝塡裝有麻醉液卡匣的卡匣保持器裝設於電動注 射器本體，藉由受驅動單元所旋轉的小齒輪與推壓棒的齒 條相齒合，使推壓棒慢慢移動而推壓裝有麻醉液卡匣之柱 塞橡膠栓，以使卡匣之中的麻醉液從卡匣通過注射針而排 出之方式所構成之牙科用麻醉液充塡卡匣式的電動注射器 ，將卡匣保持器作爲可共用於1.0ml卡匣及1.8ml卡匣的卡 匣保持器；推壓棒，係以使推壓棒之移動，可在1.0ml卡 匣及1.8ml卡匣所共通的位置處終止之方式地具有·· 1.0ml 的卡匣設定位置以及從該位置縮入之1.8ml的卡匣設定位 201242576 置：並包含有底的套筒與復位彈簧，該套筒，是 從上述共通的終端位置被壓回之推壓棒的後端部 推壓棒位於1.0ml卡匣的設定位置時，不會受到 後端面所干涉，當推壓棒被壓回1.8ml的卡匣設 ，以推壓棒的後端面將上述套筒朝向後方推壓； 簧，是用以在推壓棒前進移動時使套筒與推壓棒 前方移動。 又，在依據本發明之電動注射器之中，線圈 是被配置於有底套筒的周圍，其一端爲抵接於： 前方端所形成的周圍凸緣，其另一端爲抵接於： 射器本體之後端所設置之內孔的肩部，且在常態 筒呈抵接狀態地彈壓於動力單元的一部分，並位 推壓棒之後端面的位置。 再者又，在依據本發明之電動注射器之中， 具有比1.0ml麻醉液卡匣與1.8ml麻醉液卡匣之長 稍長之尺寸者爲理想。 再者又，在依據本發明之電動注射器之中， 棒之後端面將上述套筒朝向後方推壓時，套筒便 電動注射器本體之後端的內孔而突出。 〔發明效果〕 根據本發明，無論對於1.0ml麻醉液之卡匣: 卡匣’將其裝塡於卡匣保持器，再將該卡匣保持 連結接頭而結合於電動注射器。藉由受驅動單元 用以接納 分，且當 推壓棒的 定位置時 該復位彈 一起朝向 復位彈簧 於套筒之 於電動注 下，使套 於近接於 套筒，是 度差異還 當以推壓 貫穿設於 突1 · 8 m 1之 器，藉由 所旋轉的 -8 - 201242576 壓從被 推液是 而醉於 動麻由 移的， 慢中動 慢之移 棒匣的 壓卡棒 推使壓 使以推 合栓中 齒膠其 相橡， 條塞出 齒柱排 的的而 棒匣針 壓卡射 推液注 與醉過 輪麻通 齒有匣 小裝卡 設定成在1.0ml卡匣及1.8ml卡匣所共通的位置處終了，所 以1.8ml的卡匣設定位置，是從1.0ml的卡匣設定位置縮入 有卡匣長度上的差異量，當推壓棒從上述共通的終端位置 被壓回時，有底套筒，係接納推壓棒的後端部分，當推壓 棒到達1.0ml之卡匣的設定位置時，便不會受到推壓棒的 後端面所推壓而停留於該處，當推壓棒到達1.8ml的卡匣 設定位置時，以推壓棒的後端面朝向後推壓而將復位彈簧 予以蓄壓。因此，無論是何種卡匣之情形時，爲了使麻醉 液從卡匣通過注射針而排出，雖然皆是藉由推壓棒的前進 直線移動來推壓卡匣的柱塞橡膠栓，不過對於1.8ml之卡 匣的情形時，套筒，是藉由及於其周圍凸緣之復位彈簧的 作用而與推壓棒一起朝向前方移動，直到抵接到驅動單元 爲止。 【實施方式】 若參照圖面之第1圖時，本發明的電動注射器1，係包 含塑膠製的注射器本體2，並具備有：可裝卸自如地將裝 塡有麻醉液充塡卡匣3之金屬製的卡匣保持器4裝設於其前 端部的連結接頭5。連結接頭5，是被安裝在注射器本體2 ，且螺鎖結合於金屬製之支撐體9，該支撐體9，具有用以 使金屬製圓棒狀的推壓棒6穿通的貫通孔7、以及當卡匣保 -9 - 201242576 持器4裝設於連結接頭5時可接納卡匣保持器4的接納口 8。 卡匣保持器4，係於其對向側面，具備有：用來確認 被裝塡於其中之卡匣之方便實用的視窗4a、4b，並被提供 作爲：共用在裝有1.0ml麻醉液之卡匣3b及裝有1.8ml麻醉 液之卡匣3a，且具有：卡匣保持器4在被裝設於連結接頭5 時，其後端面4’爲可抵接於接納口 8之底的尺寸形狀。推 壓棒6，於前端具備有從後方抵接於卡匣3之柱塞橡膠栓10 的抵接體11，於推壓棒6的後方部分，於其單側形成有平 坦的齒條12。推壓棒6，只要是設成推壓KOml卡匣3b之柱 塞橡膠栓10而可使其中的麻醉液全部排出所必要的長度者 即可。 電動注射器1，係包含固定於該本體2內的作動裝置15 ，該作動裝置15，具備有包含馬達及減速機（圖示省略） 的驅動單元16，且固定安裝於其輸出軸的小齒輪17是與推 壓棒6的齒條12相齒合。元件符號18，是當把卡匣保持器4 插入至接納口 8時，以其後端面4’進行推壓而可以將與驅 動單元16之離合器（圖示省略）接連的離合用槓桿19從該 離合器解除位置操作至離合器卡合位置的控制桿。控制桿 18，是於支撐體9中’穿通於：與推壓棒6用之貫通孔7並 列所設置的貫通孔20，且當卡匣保持器4從連結接頭5拆卸 而從接納口 8抽拔時，藉由線圈狀的拉伸彈簧2 1的作用， 使離合用槓桿1 9復位回到離合器解除位置’藉此朝向接納 口 8之中往前方移動。驅動單元16的離合是藉由離合用槓 桿19的施加動作而被解除’阻斷朝向小齒輪17的動力傳達 -10- 201242576 ，而能夠藉由手動而使推壓棒6移動。 於推壓棒6的內縮位置，設有可接納其後端部分的有 底套筒22，該套筒22，係具有比1.0ml麻醉液卡匣與1.8 ml 麻醉液卡匣之長度差異還稍長之尺寸者爲佳。線圈復位彈 簧23是被配置在套筒22的周圍，其一端爲抵接於套筒22的 周圍凸緣24，另一端爲抵接於：設在電動注射器本體2後 端之內孔25的肩部26，在常態下，使套筒22呈抵接狀態地 彈壓於動力單元16的一部分。在該狀態下，套筒22是位在 近接於推壓棒6後端面的位置。又，元件符號27是電動注 射器的主開關，符號28爲微動開關，是當推壓棒6移動一 預定距離而與設置在推壓棒6的凹部29相對峙時，便由開 啓（on)切換爲關閉（off)而停止驅動單元16之馬達的旋 轉。符號30爲作爲馬達等之電源的電池盒。 在使用1.0ml麻醉液之卡匣3b的情況時，是將卡匣3b 裝塡於卡匣保持器4，再將該卡匣保持器4，抵接至其底部 爲止地插入於接納口 8而與連結接頭5結合。在此過程中， 當卡匣3b的柱塞橡膠栓10在抵接於抵接體11會將推壓棒6 稍微朝後方推壓，因而確立出：推壓棒6的後端面在不接 觸到套筒22底部的程度下爲最接近之卡匣3b的設定位置。 在使用1.8 ml麻醉液之卡匣3a的情況時，雖然將卡匣 3 a裝塡於卡匣保持器4，再將該卡匣保持器4抵接至其底部 爲止地插入於接納口 8而與連結接頭5結合，是與卡匣3b的 情況相同，不過卡匣3b的柱塞橡膠栓1〇在抵接於抵接體11 後要再將推壓棒6朝後方推壓一相當於卡匣3a與卡匣3b之 -11 - 201242576 長度相差的距離。此時，由於推壓棒6的後端面會抵接於 套筒22的底部而推壓套筒22，套筒22穿通內孔25之中而朝 後方突出，且將線圈復位彈簧23予以壓縮。因此推壓棒6 在線圈復位彈簧23之較大的反彈力下壓接於卡匣3 a的柱塞 橡膠栓10而確立出卡匣3a的設定位置。 電動注射器，將兩頭注射針（圖示省略）安裝於卡匣 保持器4的前端而與卡匣的內部連通來完成使用準備。無 論何種卡匣之情況時，電動注射器，皆是藉由操作主開關 27而動作。推壓棒6，是利用受到驅動單元16的動力傳達 而旋轉的小齒輪21與齒條12的齒合而前進，在其前端將卡 匣的柱塞橡膠栓1〇予以推壓而使卡匣內的麻醉液通過注射 針而排出。爲1 .〇ml麻醉液之卡匣的情況時，推壓棒6的前 進直線移動是一面從處於定置狀態下的套筒22拉出而一面 進行，推壓棒的前端，最後到達終端位置而完成注射。爲 1.8ml麻醉液之卡匣的情況時，藉由被壓縮之復位彈簧23 的反彈力，套筒22，在其前方端面抵接到驅動單元16的側 面爲止，是與推壓棒6—起朝向前方移動。藉由與驅動單 元16之側面的抵接而停止套筒22的移動，推壓棒6—面從 套筒22拉出並一面朝前方直線性地持續移動，到達位於與 1.0ml麻醉液之卡匣之情況時相同的終端位置而完成注射 〇 無論於何種卡匣之情況時，在注射完成時，將卡匣保 持器4從連結接頭5卸下並從接納口 8抽出。在此時點，如 先前所敘述，可以用手將推壓棒6朝向連結接頭5自由地壓 -12- 201242576 回。在壓回中，推壓棒6的後端部分會進入處於定置狀態 的套筒22之中。如先前所敘述’套筒22 ’於^0°11卡厘時 的設定位置，是不會受到推壓棒的後端面所推壓而停留於 該處，而於1.8ml卡匣時的設定位置’會在推壓棒的後端 面，一面對復位彈簧蓄壓，一面朝後方推壓。因此，無論 於何種卡匣之情況時，爲了使麻醉液從卡匣通過注射針而 排出，皆是藉由推壓棒的前進移動來推壓卡匣的柱塞橡膠 栓，不過1 . 8ml卡匣的情形是套筒利用復位彈簧的作用與 推壓棒一起朝向前方移動。 根據本發明，將卡匣保持器作爲可共用於丨.0011卡匣 及1.8 ml卡匣的卡匣保持器；推壓棒，係以使推壓棒之移 動，可在1 .Oml卡匣及1 .8ml卡匣所共通的位置處終了之方 式地具有：1.0ml的卡匣設定位置以及從該位置內縮拉入 之1.8 ml的卡匣設定位置，並由於包含：當推壓棒從上述 共通的終端位置被壓回時可接納推壓棒之後端部分的有底 套筒、以及當推壓棒被壓回1.8ml的卡匣設定位置時，以 推壓棒的後端面將上述套筒朝向後方推壓，用以在推壓棒 前進移動時使套筒可與推壓棒6—起朝向前方移動的復位 彈簧，所以利用推壓1 . 〇ml卡匣之柱塞橡膠栓所必須之長 度的推壓棒便可以推壓1.8 ml之卡匣的柱塞橡膠栓。據此 可得知，在本發明中，可使電動注射器的尺寸形狀實施成 緊緻（compact )。 【圖式簡單說明】 -13- 201242576 第1圖是使用1.0ml麻醉液卡匣之本發明的電動注射器 的斷面側面圖。 第2圖是第1圖之電動注射器的平面斷面圖。 第3圖是使用1.8ml麻醉液卡匣之本發明的電動注射器 的斷面側面圖。 第4圖是推壓棒的立體圖。 【主要元件符號說明】 1 :電動注射器 2 :注射器本體 3 =麻醉液充塡卡匣 3b : 1 .Oml卡匣 4 :卡匣保持器 4 a、4 b :視窗 4 ’ ：後端面 5 :連結接頭 6 :推壓棒 7 :貫通孔 8 :接納口 9 :支撐體 1 〇 :柱塞橡膠栓 1 1 :抵接體 1 2 :齒條 1 5 :作動裝置 -14- 201242576 1 6 :驅動單元 1 7 :小齒輪 1 8 :控制桿 1 9 :離合用槓桿 2 0 :貫通孔 2 1 :拉伸彈簧 22 :有底套筒 23 :線圈復位彈簧 24 :周圍凸緣 25 :內孔 2 6 ·肩部 2 7 :主開關 2 8 :微動開關 29 :凹部 3 0 :電池盒201242576 VI. Description of the Invention: [Technical Field of the Invention] The present invention relates to a power injector that can be commonly applied to two types of cassettes containing l.ml and 1.8 ml of anesthetic. [Prior Art] The cassette used in such a power injector is made of transparent glass and is filled with a dental local anesthetic injection. In this type of cassette, the volume of the injection liquid is 1.8tnl and 1.0ml. Since the inner diameter and the outer shape of the cassette are the same, the length will be different. Two types of cassettes are used during anesthesia. For electric syringes, the cassette is usually attached to the cassette holder, and the cassette holder is attached to the connection of the power injector, and then the two ends are attached. The injection needle is attached to the front end of the cassette holder to communicate with the inside of the cassette for use. The electric syringe includes a pressing rod for pressing the plunger rubber plug of the cassette and an actuating means for moving the pressing rod forward in order to pass the anesthetic liquid from the cassette through the injection needle. Such an actuating device generally includes a pinion that is rotated by power transmission of a driving unit including a motor and a speed reducer, and a pusher that is engaged with the pinion gear to linearly move the push rod. A rack formed by a pressure bar. In order to allow the anesthetic liquid to be placed in the cassette of the cassette holder to be ejected through the injection needle, the linear movement of the push rod must be performed at a distance corresponding to the length of the anesthetic solution accommodated by the cassette. The linear movement distance of the push rod is to close the micro switch (Off) by a specific part of the push rod, thereby stopping the rotation of the motor -5 - 201242576 to limit it. After the injection is discharged, the cartridge holder is detached from the coupling joint to dissipate the power of the drive unit, and the pinion gear is idling, and the push rod is pushed back to the syringe body by the same distance. In this process, the micro switch is in the state of being on the outside of the push rod. At present, the applicant is selling a card-type electric syringe for dental treatment, which is equipped with an anesthetic solution of 1.0 ml and 1.8 m. Since the length of the cassette is different, the pushing distance of the plunger rubber plug for pushing the anesthetic liquid to push the cassette is different, so the cassette holder and the push rod mounted on the electric injector are separated separately. Dedicated. With the spread of electric syringes, there is a desire in the dental industry for electric syringes that can be used in common in 1.0 ml and 1.8 ml anaesthetic fluid cartridges. If you think about this problem with the composition of the electric syringes so far, of course, you should also make the cassette holders share the cassettes containing 1.0ml and 1.8xnl anesthetic fluid, but for the 1.0ml and 1.8ml cassettes. If the forward end position of the common push rod is established, it is necessary for the 1.8 ml cassette to retract the starting position of the push rod into a distance corresponding to the difference in the length of the cassette. In this case, the push rod of the electric injector must have a sufficient length when pushing the plunger rubber plug of the 1.8 ml cartridge, so the push rod must extend rearward to the length of the cassette. The difference in the amount of distance, so the motor injector body must be able to protrude rearward. The invention based on such considerations is disclosed in Patent Document 1. Patent Document 1 also discloses a plunger rubber plug that blocks a pressing bar against a clicker at a constant pressure regardless of the setting position of the clicker. However, the constitution of the invention disclosed in Patent Document 1 is not necessarily an ideal invention for the purpose of compacting a power injector of -6-201242576. [Patent Document 1] Japanese Patent No. 4 1 98435 Patent Description [Problem to be Solved by the Invention] An object of the present invention is to provide a cartridge holder which can be used together for 1.0 ml and 1.8ml of anesthetic fluid is formed by the method of 'clamping rods' and the length necessary for pushing the plunger rubber plug of 1.0ml, can also be used to push the plunger rubber plug of 1.8 ml cartridge Two types of electric syringes with cassettes for dental anesthesia are used. [Technical means for solving the problem] The above object of the present invention is achieved by providing a power injector which can use two kinds of cassettes for dental anesthetic liquid, which is mounted by a joint The cartridge holder of the anesthetic fluid cartridge is mounted on the body of the electric injector, and the pinion gear rotated by the driving unit is engaged with the rack of the pushing rod, so that the pushing rod is slowly moved to push the anesthesia The plunger rubber plug of the liquid cartridge is filled with a dental anesthetic liquid which is formed by discharging the anesthetic liquid in the cartridge from the cartridge through the injection needle, and the cartridge holder is used as the cartridge holder Can be used in combination with 1.0ml cassette and 1.8ml cassette holder; push rod is used to make the push rod move, which can be terminated at the common position of 1.0ml cassette and 1.8ml cassette. The ground has a 1.0ml cassette setting position and a 1.8ml cassette setting bit 201242576 that is retracted from the position: and includes a bottomed sleeve and a return spring, the sleeve is from the above common terminal position The back end of the push rod that is pressed back is pushed When it is located at the set position of the 1.0ml cassette, it will not be interfered by the rear end face. When the push rod is pressed back to the 1.8ml card, the rear end surface of the push rod pushes the sleeve toward the rear; It is used to move the sleeve and the push rod forward when the push rod moves forward. Further, in the electric syringe according to the present invention, the coil is disposed around the bottomed sleeve, and one end thereof abuts against: a peripheral flange formed at the front end, and the other end abuts against: the ejector The shoulder of the inner hole provided at the rear end of the body is biased against a part of the power unit in a state in which the normal cylinder is in abutting state, and the position of the end surface after the rod is pushed. Further, in the electric syringe according to the present invention, it is preferable to have a length slightly longer than 1.0 ml of the anesthetic solution and 1.8 ml of the anesthetic solution. Further, in the electric syringe according to the present invention, when the rear end surface of the rod urges the sleeve toward the rear, the sleeve protrudes from the inner hole at the rear end of the motor injector body. [Effect of the Invention] According to the present invention, the cartridge of the 1.0 ml anesthetic solution is attached to the cassette holder, and the cassette is attached to the electric syringe by holding the cassette. By the driven unit for receiving the points, and when the position of the pushing rod is fixed, the resetting springs are directed toward the return spring to the sleeve for electric injection, so that the sleeve is close to the sleeve, and the difference is also pushed The pressure is inserted through the protrusion of 1 · 8 m 1 , and the pressure is -8 - 201242576, and the pressure is pushed from the liquid to be pushed, and the slow and slow moving rod is pushed. The pressure is used to push the rubber in the bolt, and the rubber is glued to the column. The rod and the needle are pressed to push the liquid and the drunken wheel is used to set the card to 1.0 ml. And the position where the 1.8ml cassette is common, the 1.8ml cassette setting position is the amount of difference from the 1.0ml cassette setting position to the length of the cassette, when the push rod is from the above common terminal. When the position is pressed back, the bottom sleeve receives the rear end portion of the push rod, and when the push rod reaches the set position of the 1.0 ml cassette, it is not pressed by the rear end surface of the push rod. Stay there, when the push rod reaches the 1.8ml cassette setting position, push the rear end of the rod toward And the accumulator will be reset after the pressing spring. Therefore, in any case of a click, in order to discharge the anesthetic liquid from the cassette through the injection needle, the plunger rubber plug of the cassette is pushed by the forward linear movement of the push rod, but In the case of a 1.8 ml cassette, the sleeve is moved forward with the push rod by the action of the return spring of the surrounding flange until it abuts against the drive unit. [Embodiment] When the first embodiment of the drawing is referred to, the electric injector 1 of the present invention includes a syringe body 2 made of plastic, and is provided with a detachable anaesthetic liquid filled with a cartridge 3 The metal cassette holder 4 is attached to the joint 5 at the front end portion thereof. The coupling joint 5 is attached to the syringe body 2, and the screw is coupled to a metal support body 9 having a through hole 7 through which a metal rod-shaped pressing rod 6 is passed through, and When the card holder -9 - 201242576 holder 4 is mounted on the joint joint 5, the receiving opening 8 of the cassette holder 4 can be received. The cassette holder 4 is provided on its opposite side with a convenient and practical window 4a, 4b for confirming the cassette mounted therein, and is provided as: shared with 1.0 ml of anesthetic solution The cassette 3b and the cassette 3a containing 1.8 ml of anesthetic fluid have a size in which the rear end surface 4' of the cassette holder 4 is abuttable against the bottom of the receiving opening 8 when it is mounted on the coupling joint 5. shape. The push rod 6 is provided with a contact body 11 having a plunger rubber plug 10 that abuts against the cassette 3 from the rear end, and a flat rack 12 is formed on one side of the push rod 6 at a rear side thereof. The push rod 6 may be any length that is required to push the plug 10 of the KOml cassette 3b to discharge all of the anesthetic liquid therein. The electric injector 1 includes an actuating device 15 fixed to the main body 2, and the actuating device 15 is provided with a driving unit 16 including a motor and a speed reducer (not shown), and a pinion 17 fixedly mounted to the output shaft thereof. It is engaged with the rack 12 of the push rod 6. The component symbol 18 is a clutch lever 19 that can be connected to the clutch (not shown) of the drive unit 16 by pressing the rear end face 4' when the latch holder 4 is inserted into the receiving port 8. The clutch is released from the position to the lever of the clutch engagement position. The control rod 18 is inserted through the through hole 20 provided in parallel with the through hole 7 for the pressing rod 6 in the support body 9, and is drawn from the receiving port 8 when the cassette holder 4 is detached from the joint joint 5. At the time of pulling out, the clutch lever 19 is returned to the clutch release position by the action of the coil-shaped tension spring 21, thereby moving forward toward the receiving port 8. The clutching of the drive unit 16 is released by the application operation of the clutch lever 19, and the power transmission to the pinion gear 17 is blocked -10- 201242576, and the push bar 6 can be manually moved. In the retracted position of the push rod 6, there is a bottomed sleeve 22 which can receive the rear end portion thereof, and the sleeve 22 has a difference in length from the 1.0 ml anesthetic solution and 1.8 ml of the anesthetic solution. A slightly longer size is preferred. The coil return spring 23 is disposed around the sleeve 22, and has one end abutting against the peripheral flange 24 of the sleeve 22, and the other end abutting against the shoulder of the inner hole 25 provided at the rear end of the electric injector body 2. In the normal portion 26, the sleeve 22 is biased against a part of the power unit 16 in an abutting state. In this state, the sleeve 22 is located at a position close to the rear end surface of the pressing rod 6. Further, the reference numeral 27 is a main switch of the electric injector, and the reference numeral 28 is a micro switch which is switched on when the push rod 6 is moved by a predetermined distance and is opposed to the recess 29 provided in the push rod 6. The rotation of the motor of the drive unit 16 is stopped for off. Reference numeral 30 is a battery case that is a power source of a motor or the like. In the case of using the cartridge 3b of the 1.0 ml anesthetic solution, the cassette 3b is attached to the cassette holder 4, and the cassette holder 4 is inserted into the receiving port 8 while being abutted to the bottom thereof. Combined with the joint 5 . During this process, when the plunger rubber plug 10 of the cassette 3b abuts against the abutting body 11, the pressing rod 6 is pushed slightly rearward, thereby establishing that the rear end surface of the pressing rod 6 is not in contact with The extent of the bottom of the sleeve 22 is the set position of the closest cassette 3b. In the case of using the cassette 3a of 1.8 ml of the anesthetic liquid, although the cassette 3a is attached to the cassette holder 4, the cassette holder 4 is inserted into the receiving port 8 while being abutted to the bottom thereof. The combination with the joint 5 is the same as that of the cassette 3b, but the plunger rubber plug 1 of the cassette 3b pushes the push rod 6 rearward after the abutment against the abutment body 11 The distance between 匣3a and 匣3b-11 - 201242576 length. At this time, since the rear end surface of the pressing rod 6 abuts against the bottom of the sleeve 22 to press the sleeve 22, the sleeve 22 passes through the inner hole 25 and protrudes rearward, and the coil return spring 23 is compressed. Therefore, the pressing rod 6 is pressed against the plunger rubber plug 10 of the cassette 3a under the large repulsive force of the coil return spring 23 to establish the set position of the cassette 3a. In the electric syringe, a two-end injection needle (not shown) is attached to the front end of the cassette holder 4 to communicate with the inside of the cassette to complete the use preparation. The electric injector operates by operating the main switch 27 regardless of the type of click. The push rod 6 is moved forward by the pinion gear 21 that is rotated by the power transmitted from the drive unit 16 and the rack 12, and the plunger rubber plug 1〇 of the click is pressed at the front end to cause the click. The anesthetic fluid inside is discharged through the injection needle. In the case of a cassette of 1. 〇ml anesthetic solution, the linear movement of the push rod 6 is performed while pulling out from the sleeve 22 in the fixed state, pushing the front end of the rod and finally reaching the end position. Complete the injection. In the case of a 1.8 ml anesthetic solution, the sleeve 22 abuts against the push rod 6 at the front end surface thereof abutting against the side surface of the drive unit 16 by the repulsive force of the compressed return spring 23. Move forward. The movement of the sleeve 22 is stopped by abutment with the side surface of the drive unit 16, and the push rod 6 is pulled out from the sleeve 22 and linearly moved forward toward the front to reach the 1.0 ml anesthetic solution. In the case of a cassette, the injection is completed at the same terminal position. When the cassette is completed, the cassette holder 4 is detached from the joint 5 and taken out from the receiving port 8 at the time of completion of the injection. At this point, as previously described, the push rod 6 can be freely pressed back toward the joint joint 5 by hand -12-201242576. In the pressback, the rear end portion of the push rod 6 enters the sleeve 22 in the set state. As described earlier, the set position of the 'sleeve 22' at ^0°11 kPa is not pressed by the rear end surface of the push rod and stays there, but at the set position of the 1.8 ml cassette. 'When the rear end face of the push rod is pressed against the return spring, it pushes back toward the back. Therefore, regardless of the type of click, in order to allow the anesthetic fluid to be discharged from the cassette through the injection needle, the plunger rubber plug of the cassette is pushed by the forward movement of the push rod, but 1.8 ml In the case of a cassette, the sleeve is moved forward with the push rod by the action of the return spring. According to the present invention, the cassette holder is used as a cassette holder which can be commonly used for the 00.0011 cassette and the 1.8 ml cassette; the push rod is used to move the push rod, and can be used in the 1.0 ml cassette and The position common to the 1. 8ml cassette has a position of 1.0 ml and a set position of 1.8 ml which is retracted from the position, and contains: when the push rod is from the above When the common end position is pressed back, the bottom sleeve of the rear end portion of the push rod can be received, and when the push rod is pressed back to the 1.8 ml set position, the sleeve is pressed to the rear end surface of the rod. Pushing toward the rear, the return spring for moving the sleeve forward with the push rod 6 when the push rod moves forward, so it is necessary to push the plunger rubber plug of the 〇ml cartridge The length of the push rod pushes the plunger of the 1.8 ml cartridge. From this, it can be seen that in the present invention, the size and shape of the electric injector can be made compact. BRIEF DESCRIPTION OF THE DRAWINGS -13- 201242576 Fig. 1 is a cross-sectional side view showing the electric syringe of the present invention which is stuck with 1.0 ml of anesthetic solution. Fig. 2 is a plan sectional view showing the electric injector of Fig. 1. Fig. 3 is a cross-sectional side view showing the electric syringe of the present invention which is jammed with 1.8 ml of anesthetic fluid. Figure 4 is a perspective view of the push rod. [Main component symbol description] 1 : Power injector 2 : Syringe body 3 = Anesthetic fluid charging cassette 3b : 1 .Oml cassette 4 : cassette holder 4 a, 4 b : Window 4 ' : Rear end face 5 : Link Joint 6: push rod 7: through hole 8: receiving port 9: support body 1 柱塞: plunger rubber plug 1 1 : abutment body 1 2 : rack 1 5 : actuating device - 14 - 201242576 1 6 : drive unit 1 7 : pinion gear 1 8 : lever 1 9 : clutch lever 2 0 : through hole 2 1 : tension spring 22 : bottom sleeve 23 : coil return spring 24 : peripheral flange 25 : inner hole 2 6 · Shoulder 2 7 : Main switch 2 8 : Micro switch 29 : Recess 3 0 : Battery case