美國科士巴格FORMSPRAG單向離合器又稱FORMSPRAG單向離合器、FORMSPRAG單向軸承或FORMSPRAG逆止器，也是*能單一方向（順時針或逆時針方向）傳動的機械傳動基礎件，當動力源驅動被動元件時只能單一方向傳動，若動力源轉變方向時，（如順時針變為逆時針方向），被動元件則會自動脫離不產生任何動力傳送的功能。
型號列舉：FORMSPRAG離合器#708；MODEL 600；MODEL #708 WITH FSO 700 CLUTCH；036-01-007-6；BB35-2K；FSR-3/.500GRGH；FS-04 R.H；備件CL43152-3……
FORMSPRAG公司旗下品牌產品有：Matrix International、英(ying)(ying)國(guo)(guo)Matrix電磁離(li)(li)(li)(li)合(he)(he)(he)器(qi)(qi)(qi)(qi)(qi)(qi)、Matrix離(li)(li)(li)(li)合(he)(he)(he)器(qi)(qi)(qi)(qi)(qi)(qi)、Matrix制(zhi)(zhi)(zhi)動(dong)器(qi)(qi)(qi)(qi)(qi)(qi)、Matrix剎車(che)盤；Warner Linear Warner電動(dong)推桿、Warner滑軌；TB Wood‘s:TB Wood''s聯(lian)(lian)(lian)軸(zhou)(zhou)器(qi)(qi)(qi)(qi)(qi)(qi)， TB Wood‘s皮(pi)帶驅動(dong)器(qi)(qi)(qi)(qi)(qi)(qi)，TB Wood‘s離(li)(li)(li)(li)合(he)(he)(he)器(qi)(qi)(qi)(qi)(qi)(qi)及制(zhi)(zhi)(zhi)動(dong)器(qi)(qi)(qi)(qi)(qi)(qi)；　　Wichita Clutch and Industrial Clutch：Wichita Clutch制(zhi)(zhi)(zhi)動(dong)器(qi)(qi)(qi)(qi)(qi)(qi)、Wichita離(li)(li)(li)(li)合(he)(he)(he)器(qi)(qi)(qi)(qi)(qi)(qi)；Twiflex Limited：英(ying)(ying)國(guo)(guo)Twiflex聯(lian)(lian)(lian)軸(zhou)(zhou)器(qi)(qi)(qi)(qi)(qi)(qi)、英(ying)(ying)國(guo)(guo)Twiflex控(kong)(kong)制(zhi)(zhi)(zhi)器(qi)(qi)(qi)(qi)(qi)(qi)、Twiflex控(kong)(kong)制(zhi)(zhi)(zhi)板、Twiflex執(zhi)行器(qi)(qi)(qi)(qi)(qi)(qi)、Twiflex插件板、Twiflex夾鉗；Formsprag Clutch：美(mei)(mei)(mei)國(guo)(guo)Formsprag Clutch 離(li)(li)(li)(li)合(he)(he)(he)器(qi)(qi)(qi)(qi)(qi)(qi)、Formsprag剎車(che)、Formsprag軸(zhou)(zhou)承(cheng)、Formsprag分度卡(ka)盤、Marland Clutch：美(mei)(mei)(mei)國(guo)(guo)Marland Clutch 離(li)(li)(li)(li)合(he)(he)(he)器(qi)(qi)(qi)(qi)(qi)(qi)、Marland制(zhi)(zhi)(zhi)動(dong)器(qi)(qi)(qi)(qi)(qi)(qi)、Marland軸(zhou)(zhou)承(cheng)；Stieber Clutch：德國(guo)(guo)Stieber離(li)(li)(li)(li)合(he)(he)(he)器(qi)(qi)(qi)(qi)(qi)(qi)、STIEBER離(li)(li)(li)(li)合(he)(he)(he)器(qi)(qi)(qi)(qi)(qi)(qi)、Stieber單向離(li)(li)(li)(li)合(he)(he)(he)器(qi)(qi)(qi)(qi)(qi)(qi)、STIEBER逆止器(qi)(qi)(qi)(qi)(qi)(qi)、STIEBER單向軸(zhou)(zhou)承(cheng)；Boston Gear：美(mei)(mei)(mei)國(guo)(guo)Boston離(li)(li)(li)(li)合(he)(he)(he)器(qi)(qi)(qi)(qi)(qi)(qi)、Boston Gear 減(jian)速機(ji)、Boston軸(zhou)(zhou)承(cheng)、Boston制(zhi)(zhi)(zhi)動(dong)器(qi)(qi)(qi)(qi)(qi)(qi)、Boston抱閘；Huco Dynatork：Huco Dynatork空氣(qi)馬達(da)、Huco Dynatork聯(lian)(lian)(lian)軸(zhou)(zhou)器(qi)(qi)(qi)(qi)(qi)(qi)；Ameridrives Couplings：美(mei)(mei)(mei)國(guo)(guo)Ameridrives齒(chi)輪聯(lian)(lian)(lian)軸(zhou)(zhou)器(qi)(qi)(qi)(qi)(qi)(qi)、Ameridrives**聯(lian)(lian)(lian)軸(zhou)(zhou)器(qi)(qi)(qi)(qi)(qi)(qi)、Ameridrives彈性聯(lian)(lian)(lian)軸(zhou)(zhou)器(qi)(qi)(qi)(qi)(qi)(qi)、Ameridrives萬(wan)向聯(lian)(lian)(lian)軸(zhou)(zhou)器(qi)(qi)(qi)(qi)(qi)(qi)；Industrial Clutch：美(mei)(mei)(mei)國(guo)(guo)Industrial Clutch離(li)(li)(li)(li)合(he)(he)(he)器(qi)(qi)(qi)(qi)(qi)(qi)、Industrial Clutch制(zhi)(zhi)(zhi)動(dong)器(qi)(qi)(qi)(qi)(qi)(qi)、Industrial Clutch液(ye)壓控(kong)(kong)制(zhi)(zhi)(zhi)；Bibby Transmissions：英(ying)(ying)國(guo)(guo)Bibby聯(lian)(lian)(lian)軸(zhou)(zhou)器(qi)(qi)(qi)(qi)(qi)(qi)、Bibby力矩限制(zhi)(zhi)(zhi)器(qi)(qi)(qi)(qi)(qi)(qi)；Nuttall Gear and Delroyd Worm Gear：　　美(mei)(mei)(mei)國(guo)(guo)Nutall Gear 減(jian)速機(ji)、Nutall齒(chi)輪馬達(da)；

Saftek Friction：Saftek Friction控制器；　　Altra Industrial Motion ：Asia Pacific and Africa。
Formsprag Clutch (South Beloit, IL) has introduced a new high speed backstop designed with inner race centrifugal throw-out sprags to meet the backstopping requirements of inclined conveyors or bucket elevators that use a gear reducer with the backstop mounted externally on the high speed or intermediate shaft.