| QUICK HITCH SAFETY |
QUICK HITCH SAFETY Quick hitches have been around for over 20 years and have become the primary device used to couple attachments to excavators. There success is due to the massive time/labour savings they give operators on site and are a common place on over 90% of excavators in the UK today.Quick hitches come in three distinctive forms: SEMI – meaning manually operated by spring and lever, screw or the insertion of one attachment pin. SEMI AUTO- meaning activated by hydraulic ram and locked by the manual insertion of a safety pin. FULLY AUTO - meaning activated by a hydraulic ram, with a self locking mechanism. All mainstream coupler manufacturers in the UK/Ireland supply both the manually inserted safety pin type coupler and the full auto-lock coupler. These manufacturers ALL have different patented auto-locking systems which differ in the levels of failure scenarios which they safeguard against. Some of these mechanisms lock the rear pin of the attachment with gravity feed systems, while others use a combination of hydraulic and spring operated mechanisms to lock the front pin of the attachment. The main causes for attachments being lost from couplers are first and foremost: 1. Operator error/misuse 2. Mechanical failure of the hydraulic ram/solenoid In most instances it is the lethal combination of these two failures which results in the untimely release of an attachment from the coupler, resulting in serious injury or death. It has been identified that semi auto quick hitches (safety pin type) are most common in these accidents. This type of quick hitch is continually failing, as it relies on the operator to manually insert a safety pin/bar each time they change attachments. This is in stark contrast to the fact that the safety pin type couplers are the safest locking couplers in the industry if used correctly. The most common of these accidents occur: 1. When operators are moving buckets/attachments around site without making a full connection 2. Where they pick-up a bucket in the open front jaw of the coupler and slew around to place it further up the site. It is during this slewing action where the bucket is most vulnerable and has become untimely detached. Each quick hitch manufacturer supplies operating instructions for their couplers, usually as a sticker for inside the cab. In these instructions we commonly find a step by step operating guide along with a section referring to “performing a bucket test after connection”. It is well known that operators almost never perform such a test to ensure the attachment is connected properly to the coupler. And it is with this knowledge that coupler manufacturers must now look towards auto-locking mechanisms that prevent the operator from getting a bucket into the coupler without it being safely secured. The main lesson learned is that the more responsibility we can remove from the operator, the safer the coupler becomes, hence full auto-locking couplers are the answer to reducing accidents on site with there self locking mechanisms. From what we have learned about the most common causes of accidents it would be prudent to use an auto-locking coupler which locks the front pin of the attachment as soon as it enters the front jaw of the coupler which includes a visual indicator to help the operator to identify that the attachment is secured. The new CJM auto-locking coupler has been developed to combat all the known operator and mechanism failures we have learned about from the accidents involving attachments being untimely released from couplers. Due to its simply elegant design it offers the most reliable solution to preventing the four most likely causes of unintended attachment release. (a) The operator is unable to pick-up an attachment without safely securing it into the front jaw of the coupler due to the mechanism operation. (b) In the event of hydraulic ram failure, the front pin remains locked. (c) If either the switch is accidentally operated in the cab or the solenoid fails, the CJM coupler will continue to lock the front pin of the attachment. The CJM coupler has the broadest range of failure scenarios, both operator and mechanical covered by its operation and auto locking systems, thereby offering the safest solution for this application in the industry today. |