|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
Definitions VERTICAL
LIFT: During the turning
operation the edge of the plate opposite the edge to which the clamp
is attached
HORIZONTAL
LIFT: Clamps (used in pairs or multiples) are attached to the
side edges of a plate or STEEL PLATES:
Unless otherwise specified, lifting clamps are manufactured to handle
hot-rolled steel plates whose Brinell Hardness does not exceed 300. FINISHED
AND POLISHED PLATES: Steel plates in this category having other
than hot-rolled surfaces such as stainless steel, etc., are generally
handled using non-marring clamps incorporating smooth gripping surfaces. STRUCTURAL
MEMBERS -- FABRICATED SECTIONS: Unless otherwise specified,
clamps described as capable of handling structural members and fabricated
sections are limited to hot-rolled steel whose Brinell Hardness
does not exceed 300. RATED CAPACITY:
ALL RENFROE CLAMPS ARE RATED INDIVIDUALLY. The rated capacity
of a RENFROE product is based on the product being in 'new or as
new' condition and represents the maximum load the product is to
be subjected to when utilized in the manner described in this manual.
Wear, misuse, abuse and other factors relating to usage may reduce
the rated capacity. A 20% UNDERLOADING CAN BE ALLOWED WHEN THE CONDITIONS
AND WARNINGS ARE MET IN THIS MANUAL. UNDER LOADING OCCURS WHEN LESS
THAN 50% OF LOAD RATING OF A CLAMP IS LIFTED. Shock loading and
the factors listed must be taken into consideration when selecting
a RENFROE product for a given application. PLATE THICKNESS:
The minimum and maximum plate thickness a clamp specified for
handling plates is capable of lifting. JAW OPENING:
The minimum and maximum thickness of a member of a clamp specified
as having a JAW OPENING is capable of handling. OPERATING
TEMPERATURES: Unless specified under the Applications Section
of the individual model, the approved operating temperature of RENFROE
clamps is from zero degrees Fahrenheit (-18 Celsius) to a maximum
of 200 degrees Fahrenheit (+93 degrees Celsius). The minimum and
maximum temperatures apply to both ambient and the material being
handled by the clamp. 'HOT LIFTS':
The Model R and S clamps are available in modifications that are
capable of making lifts where the temperatures of the member being
lifted exceeds 200 degrees Fahrenheit (+93 degrees Celsius). Depending
on conditions a lift may exceed 1000 degrees Fahrenheit (538 degrees
Celsius). The exact application and temperatures of the plates to
be handled are critical in selecting the proper model. LOCKING CLAMPS: Locking clamps are divided into the categories listed below. With the exception of the 'Locking Wedge' and 'Locking Screw' type the purpose of the locks are to facilitate the attaching and removing of the clamp from the member being handled. 'Lock Closed' - an overcenter spring loaded mechanism in which the spring exerts a force on the gripping cam when the lock handle is moved to the 'Lock Closed' position. When the handle is moved to unlocked position the force exerted by the spring is relaxed and the gripping cam may be retracted by pushing the lifting shackle into the body of clamp. Refer to the Operation Section of specific models of 'Lock Closed' clamps for additional details. Typical 'Lock Closed' clamps are Models DG, FR, M and HRS. 'Lock Open Only' - normally used on 'Hot Lift' clamps and consists of a manually operated 'Lock Stop Pin' that is inserted when gripping cam of clamp is retracted and removed when clamp is positioned on the plate. Tag line may be used to permit operator to remove pin from a greater distance from clamp. Refer to the Operation Section of specific model of 'Lock Open Only' clamps for additional details. Typical 'Lock Open Only' clamp is the Model RO. 'Lock Open-Lock Closed' - an over-center spring loaded mechanism in which the spring exerts a force on the gripping cam when the lock handle is moved to the 'Lock Closed' position. When the handle is moved to the 'Lock Open' the gripping cam is maintained in the retracted position for ease in installing the clamp on a plate or member. The Model FRD contains individual 'Lock Open' and 'Lock Closed' mechanisms that must be operated separately. Refer to the Operation Section of specific models of the 'Lock Open-Lock Closed' clamps for additional details. Typical 'Lock Open-Lock Closed' clamps are Models FRD, R, S, SD, SEA, SX, TL, TLA and the J-Series. 'Locking Wedge' - is a fluted steel wedge that is driven in place with a hammer. The body of the wedge is positioned in a slot in the clamp body with the fluted edges contacting the member to which the clamp is being attached. Refer to Operation Section of specific models of the 'Locking Wedge' clamps for additional details. Typical 'Locking Wedge' clamps are Models A1, B1, B2 and PB. 'Locking Screw' - 'Lock Screw' clamps depend on manually adjusting a screw to hold the gripping surface in place for lifting and removing the clamp from member being lifted. Refer to Operation Section of a specific model of 'Locking Screw' clamps for additional details. Typical 'Locking Screw' clamps are Models AC, ACP, BC, NM, PC, SCP, SCPA and RSC. NON-LOCKING: 'Non-Locking' clamps have no mechanisms to aid in attaching or removing clamp from member being lifted. It is necessary to have position of clamp maintained on the member being lifted until a properly applied force is exerted to the lifting shackle. Refer to Operation Section of specific models of the 'Non-Locking' clamps for additional details. Typical 'Non-Locking' clamps are Models AST, ASTL, BD, HR, HDR , HRS and WHSR. WARNING: A pointing out and notice of danger. The purpose of a 'WARNING' is to apprise the operator and all other affected persons of the existence of danger of which he should be but may not be aware; and to enable the operator to protect himself and others, where applicable, against such danger. An attempt is made herein to warn against reasonable and reasonably foreseeable danger in the proper use and possible reasonable misuse of RENFROE products described in this manual. |
||
The
lifting of a single plate or member in which the lifting force exerted
by the rigging is directly above and in line with the lifting shackle
as shown in the illustration at right. 
should always be in contact with a supporting surface such as a
factory floor and the load on the clamp should not exceed one half
rated capacity of clamp - refer to illustrations shown below.
bundle
of plates positioned horizontally to the floor level. The rigging
attached to clamps is generally multi-legged slings with the connecting
point of the slings being approximately centered between the distance
separating the clamps. Refer to illustrations shown below.