Fail-safe locking arrangement for refuse collection vehicle
United States Patent 1 1 Brisson Apr. 1, 1975 1 FAIL-SAFE LOCKING ARRANGEMENT FOR REFUSE COLLECTION [75] Inventor: John R. Brisson, Kingsford, Mich.  
 [73] Assignee&#39;. Lodal 1nc., Kingsford, Mich.  
 [22] Filed: Sept. 13, 1973 121] Appl. No.: 396,846  
 [52] US. Cl. 214/302, 214/145 Primary E.\&#39;uminet&#39;A1bert J. Makay Assistant E.raminerLawrence J. Oresky Attorney, Agent, or Firm-Andrus, Sceales, Starke &amp; Sawall [57] ABSTRACT A refuse collection vehicle includes a body with a top opening through which refuse and the like is dumped by means of a pivoting boom having a refuse container thereon. The container is removably attached to the boom assembly by interengaging male and female members which are lockable together.  
 A pair of opposed locking pins are associated with the male member on the boom assembly and are adapted to enter pin-receiving Openings associated with the female member on the refuse container. The locking pins are continuously biased outwardly as by springs to secure the boom assembly and container together. When the boom is in or adjacent its lowered position, as when interengaging the male and female locking members, a compressed air system overcomes the spring biasing force to keep the locking pins retracted. A compressed air exhaust valve is responsive -to upward boom movement to once again bring the biasing force into play to provide locking. The refuse container cannot become unlocked and fall at any position of the boom, even if the compressed air control system should fail.  
 8 Claims, 5 Drawing Figures AIENIEB APR 1 I975 SHEEI 1 0f 2 FAIL-SAFE LOCKING ARRANGEMENT FOR REFUSE COLLECTION BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to refuse collection vehicles and more particularly to a fail-safe locking arrangement therefor.  
  In US. Pat. No. 3,016,157 there is disclosed a loader apparatus including a vehicle having a body with a top opening through which refuse and the like is dumped by means of a pivoting boom having a refuse container thereon. The container is removably attached to the boom assembly by interengaging male and female members which are locked together by a position responsive mechanical linkage arrangement.  
  The present invention is directed to an improvement over the previous locking structure whereby a compressed air responsive arrangement permits biased locking of the members upon raising of the boom. A fail-safe system assures that the lock will hold, even if the compressed air system fails.  
  More particularly, a pair of opposed locking pins are associated with the male member on the boom assembly and are adapted to enter pin-receiving openings associated with the female member on the refuse container. The locking pins are continuously biased outwardly, as by springs to secure the boom assembly and container together. When the boom is in or adjacent its lowered position, as when interengaging the male and female locking members, a compressed air system overcomes the spring biasing force to keep the locking pins retracted. A compressed air exhaust valve is responsive to upward boom movement to once again bring the biasing force into play to provide locking. The refuse container cannot become unlocked and fall at any position of the boom, even if the compressed air control system should fail.  
 BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings illustrate the best mode presently contemplated by the inventor for carrying out the invention.  
 In the drawings:  
  FIG. 1 is a side elevation of a refuse collection vehicle incorporating the concepts of the invention;  
  FIG. 2 is an enlarged fragmentary perspective view showing the male and female interengaging members prior to engagement;  
  FIG. 3 is an enlarged fragmentary rear elevation of the male interengaging member and associated parts with the locking pins in retracted position;  
  FIG. 4 is a view similar to FIG. 3, with the locking pins extended&#34;, and  
  FIG. 5 is a schematic view of the boom position responsive locking control system.  
 DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 1 of the drawings, the invention is contemplated for use in a refuse collection vehicle 1 having a cab 2, a chassis frame 3, and a body 4 for receiving and storing refuse for subsequent discharge. Body 4 is provided with an opening 5 in its top, with the opening having a suitable closure 6.  
  A boom assembly 7 of generally inverted U-shape is pivoted at its rearward end to body 4, as by a transverse boom mounting shaft 8. As shown in FIG. 1, assembly 7 is pivotable upwardly from a forward lowered position to a rearward dumping position, as by a suitably actuated boom cylinder 9.  
  The forward portion of boom assembly 7 is adapted to removably receive a refuse container 10 for dumping into body 4. For this purpose, a male interengaging member 11 is pivotally mounted on the front end portion of assembly 7, while a female interengaging member 12 is fixedly secured to a wall of container 10. See FIG. 2.  
  Male member 11 includes a generally triangular upper portion 13 and a lower base portion 14, the latter including end walls or supports 15. Female member 12 includes an upper portion having a pair of downwardly extending divergent legs 16, which form an inverted triangle for supporting receipt of male portion 13. Each leg 16 merges downwardly into a generally straight arm 17 having an opening 18 therein, for purposes to be described.  
  In accordance with the invention, members ll and 12 are adapted to be engaged and releasably locked together. For this purpose, and as best shown in FIGS. 3 and 4, a pair of spaced linkage arms 19 are disposed behind triangle 13 and are pivotally mounted between their ends to a support 20 on boom assembly&#39;7, as at pivot points 21. Arms 19 are disposed generally vertically when assembly 7 is in its lowered position, and the lower arm end portions are pivotally secured, as at 22, to a pair of opposed horizontal locking pins 23 which slideably extend through male base end walls 15.  
  Pins 23 are continually biased toward their extended position. For this purpose, a spring 24 is connected between boom assembly support 20 and a bracket 25 on the respective linkage arm below each pivot point 21. When male and female members 11 and 12 are interengaged, they may be locked together by spreading extension of pins 23 into female member openings 18.  
  The invention contemplates control means for selective retraction of locking pins 23, as during engagement or disengagement of refuse container 10 from boom assembly 7, with the control means being responsive to the boom assembly angular position to retract or permit extension of the pins.  
  For this purpose, vehicle 1 includes a source of pressurized air, such as a tank 26 which is connected through a valve 27 to an air control unit 28 mounted to the upper end portion of one of the linkage arms 19. Control unit 28 may be of any suitable type, and is shown as being of the diaphram actuated air chamber type wherein when pressure is applied from tank 26, a rod 29 on the unit will be caused to extend. The outer end of rod 29 is pivotally secured to the upper end portion of the other linkage arm 19. Thus, when unit 28 is pressurized, as in FIG. 3, and rod 29 extends, arms 19 will pivot against the force of springs 24 to retract pins 23. When the pressure is off, rod 29 will retract so that springs 24 will cause extension of locking pins 23, as in FIG. 4.  
  Air control unit 28 and the resultant locking pin operation is responsive to positioning of the boom assembly. For this purpose, a cam 30 is adjustably mounted on boom mounting shaft 8 and is positioned to engage and actuate valve 27. See FIG. 5. When assembly 7 is in its generally lowered position, cam 30 is in engagement with valve 27, so that air will actuate control unit 28 to retract pins 23. As the boom assembly is raised,  
 cam 30 will disengage from valve 27 so that air in the chamber of unit 28 will be exhausted back through the valve and a line 31 to cause springs 24 to extend the pins into locking position.  
  Because pins 23 remain extended if there is no air pressure at unit 28, a fail-safe system is provided wherein failure of the air system will not cause unlocking with the possible disengagement of refuse container from boom assembly 7 when they are in a raised position.  
  While the control system has been described relative to the use of air, other gases or fluids may be used without departing from the spirit or scope of the invention.  
  Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.  
 1 claim:  
  1. In a refuse collection vehicle for use with a refuse container having a female interengaging member, the combination comprising:  
 a. a body on said vehicle and having an opening for receiving refuse,  
 b. a boom assembly pivotally mounted on said vehicle for carrying a said refuse container between a lowered position and a raised dumping position,  
 c. a male interengaging member mounted on said boom assembly and adapted to supportingly engage the said female member,  
 d. locking means associated with said male member for selective locking engagement with said female member,  
 e. means normally biasing said locking means toward locking position,  
 f. and means responsive to the angular position of said boom assembly for overcoming said biasing means for disengaging said locking means from said female member.  
  2. in a refuse collection vehicle for use with a refuse container having a female interengaging member, the combination comprising:  
 a. a body on said vehicle and with said body having an opening for receiving refuse,  
 b. a boom assembly pivotally mounted on said vehicle for carrying a said refuse container between a lowered position and a raised dumping posit1on,  
 c. a male interengaging member mounted on said gage the said female member,  
 d. locking means associated with said male member for selective locking engagement with said female member, said locking means comprising a pair of opposed extendable-retractable pins,  
 e. a pair of generally vertical linkage arms pivotally mounted between their ends to said boom assembly, and with the lower end portions of said arms pivotally mounted to said pins,  
 f. means normally biasing said locking means toward locking position and with said biasing means comprising springs extending between said boom assembly and said linkage arms between said firstnamed and second-named pivotal mountings,  
 g. and means for overcoming said biasing means for disengaging said locking means from the saidfemale member.  
 3. The combination of claim 2 in which said means for overcoming said biasing means comprises:  
 a. extensible means connecting the upper end portions of said linkage arms to cause pivoting of the linkage arms about the first-named pivotal mounting,  
 b. and means to actuate said extensible means.  
  4. The combination of claim 3 which includes means responsive to the angular position of said boom assembly for operating said actuating means.  
 5. The combination of claim 3 in which;  
 a. said extensible means comprises a rod connected to an air chamber,  
 b. and said actuating means comprises:  
 1. a source of pressurized air,  
 2. and&#39;a valve connected between said source and said air chamber for pressurizing said chamber to extend said rod or alternately to exhaust said chamber to retract said rod.  
  6. The combination of claim 5 in which said air chamber is secured to the upper end portion of one of said linkage arms.  
  7. The combination of claim 5 which includes cam means responsive to the angular position of said boom assembly for operating said valve.  
 8. The combination of claim 1 in which said means for overcoming said biasing means is cam operated.