A column protection apparatus includes a number of impact absorbing members, each impact absorbing member including a protrusion and a protrusion receiving opening. The protrusion of each impact absorption member is inserted into the protrusion receiving opening of another, different impact absorption member such that a column-receiving opening is formed through the impact absorbing members.

CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 62/107,102 filed Jan. 23, 2015, which is incorporated by reference. 
    
    
     BACKGROUND 
     This invention relates to a column protector for an industrial facility. 
     Warehouses, distributions centers, factories, and similar facilities often have large stock handling equipment such as fork trucks which frequently move stock into, out of, and around the facility. In some examples, facilities may have columns (e.g., support columns) which are located in areas commonly traversed by the stock handling equipment. 
     SUMMARY 
     As an operator navigates stock handling equipment through a facility, it is possible for the operator to cause the equipment to collide with a support column, potentially causing damage to the column and/or the equipment. 
     In a general aspect, a column protection apparatus includes a number of impact absorbing members, each impact absorbing member including a protrusion and a protrusion receiving opening. The protrusion of each impact absorption member is inserted into the protrusion receiving opening of another, different impact absorption member such that a column-receiving opening is formed through the impact absorbing members. 
     Aspects may include one or more of the following features. 
     At least some of the protrusions of the impact absorption members may be partially inserted into a protrusion receiving opening of another, different impact absorption member. Each impact absorbing member may include one or more grooves for receiving a portion of a securing strap. A top surface of each impact absorbing member may have a rounded shape. Each impact absorbing member may be substantially L-shaped. The protrusion of each impact absorbing member may include a protrusion alignment member and the protrusion receiving opening of each impact absorbing member may include an opening alignment member configured to interact with the protrusion alignment member to align the protrusion in the protrusion opening. The protrusion alignment member may include a groove and the opening alignment member may include a groove configured to receive the groove to align the protrusion in the protrusion opening. 
     At least one of the impact absorbing members may include a recess for accommodating a strap tightening tool. The impact absorbing apparatus may include a proximity sensing alarm for alerting approaching vehicles of an impending collision with the impact absorbing apparatus. The impact absorbing apparatus may include a rotatable outer shell for impact deflection. The impact absorbing members may be formed from a high density polyethylene (HDPE) material. One or more of the impact absorbing members may include a strengthening rib on an outer surface thereof. 
     Aspects may have one or more of the following advantages. 
     Among other advantages, the adjustable column protector is configured for snug and secure installation onto a wide range of column sizes. 
     The adjustable column protector is easily installed and offers  360  degree protection of a column from collisions. 
     The adjustable column protector provides damage prevention in that it protects the column, protects the equipment that hits may hit a column, it protects equipment operators, and it avoids scratching equipment and the associated equipment repainting. 
     The adjustable column protector can be used indoors or outdoors. 
     The adjustable column protector is abrasion resistant. 
     Other features and advantages of the invention are apparent from the following description, and from the claims. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a first configuration of an adjustable column protector. 
         FIG. 2  is a side view of the adjustable column protector of  FIG. 1 . 
         FIG. 3  is a top view of the adjustable column protector of  FIG. 1 . 
         FIG. 4  is a rear-perspective view of a corner section of the adjustable column protector. 
         FIG. 5  is a front-perspective view of the corner section of  FIG. 4 . 
         FIG. 6  is a top view of the corner section of  FIG. 4 . 
         FIG. 7  is a perspective view of a second configuration of the adjustable column protector. 
         FIG. 8  is a side view of the adjustable column protector of  FIG. 7 . 
         FIG. 9  is a top view of the adjustable column protector of  FIG. 7 . 
         FIG. 10  is a front perspective view of a third configuration of an adjustable column protector. 
     
    
    
     DESCRIPTION 
     Referring to  FIG. 1 , an adjustable column protector  100  is installed on a column  102  (e.g., an I-beam support column). The adjustable column protector  100  includes four corner sections  104  (with only three visible in  FIG. 1 ), sometimes referred to as ‘impact absorbing members,’ nested within one another such that a portion of the column  102  is fully enveloped by the adjustable column protector  100 . The column protector  100  covers and protects both the corners and the sides of the portion of the column  102 . 
     As is described in greater detail below, the column protector  100  can be adjusted to closely fit any column that has a size within a predetermined range (e.g., 8″ to 12″ columns) while still maintaining coverage and protecting both the corners and the sides of the portion of the column  102 . 
     In some examples, the four corner sections  104  are held together using one or more straps  106  (e.g., ratchet ties, Velcro straps, cam straps, etc.) that are disposed in one or more grooves  108  of the corner sections  104 . 
     Referring to  FIG. 2 , a side view of the adjustable column protector  100  shows two corner sections  104  abutting one another at a central plane  107 . In this configuration, the column protector is adjusted to its smallest size (e.g., to fit an 8″ column). Each of the corner sections  104  has a flat bottom surface  105  such that the column protector  100  rests flatly on the ground. 
     Referring to  FIG. 3 , a top view of the adjustable column protector  100  shows the four corner sections  104  adjusted to closely fit the column  102 , with little or no clearance between the column and the inner surfaces  314  of corner sections  104 . 
     Referring to  FIG. 4 , each corner section  104  is a substantially L-shaped member having an outer surface  412 , an inner surface  414 , a protrusion  416 , and a bumper  418  having a top surface  410  including a protrusion receiving slot  420 . 
     In some examples, the outer surface  412  has a rounded shape for increased impact deflection. The inner surface  414  forms a right angle and is configured to rest against the column  102  when the adjustable column protector  100  is installed. The bumper  418  is configured to face away from the column  102  and to protect the corner of the column from the force of collisions with stock handling equipment. In some examples, the top surface  410  of the bumper  418  is rounded to prevent accumulation of debris and liquids (e.g., water). 
     In general, the protrusion  416  of each corner section  104  is configured for partial or full insertion into the protrusion receiving slot  420  of another, different corner section  104 . Similarly, the protrusion receiving slot  420  of each corner section  104  is configured for partially or fully receiving the protrusion  416  of another, different corner section  104 . In some examples, each corner section  104  is identical. 
     When the protrusion  416  is only partially inserted into the protrusion receiving slot  420  (e.g., when installed on a larger column), the sides of the column  102  are covered and protected by the protrusion  416 . 
     In some examples, the protrusion receiving slot  420  includes one or more alignment ridges  422  for ensuring proper alignment of the corner sections  104  when the protrusion  416  of one corner section  104  is inserted into the protrusion receiving slot  420  of another corner section. 
     Referring to  FIG. 5 , in some examples, the protrusion  416  includes one or more alignment grooves  524  for receiving the alignment ridges  422  of the protrusion receiving slot  420  of another corner section  104  in order to ensure proper alignment of the two corner sections  104  when assembled. 
     Referring to  FIG. 6 , a top view of the corner section  104  shows the substantial L-shape of the member as well as the relative thicknesses of the protrusion  416  and the bumper  418 . 
     Referring to  FIG. 7 , when the adjustable column protector  100  is installed, the four corner sections  104  are assembled such that each corner section  104  has its protrusion  416  in the protrusion receiving slot  420  of another, different corner section  104 . Similarly, each corner section  104  has the protrusion  416  of another, different corner section  104  in its protrusion receiving slot  420 . In general, the degree to which the protrusions  416  are inserted into the protrusion receiving slots  420  depends on the dimensions of the column  102 . 
     In  FIG. 7 , since the adjustable column protector  100  is installed on a larger column (e.g., an 11″ column), the protrusions  416  of the corner sections  104  are only partially inserted into the protrusion receiving slots  420  of the other corner sections  104 . However, the portion of the column  102  is still fully enveloped by the adjustable corner guard  100 , with the protrusions covering the sides of the portion of the column  102  and the bumpers  418  covering the corners of the portion of the column  102 . 
     Referring to  FIG. 8 , a side view of the adjustable column protector  100  shows two corner sections  104  with the protrusion  416  of one corner section  104  partially inserted into the protrusion receiving slot  420  of another corner section. In this configuration, the column protector is adjusted to a larger size, to fit a larger column  102  (e.g., an 11″ column). 
     Referring to  FIG. 9 , a top view of the adjustable column protector  100  shows the four corner sections  104  adjusted to have the inner surfaces  414  of the bumpers  418  closely fit the column  102 , with little or no clearance between the corners of the column and the inner surfaces  418 . In some examples, a space exists between the sides of the column  102  and the inner surfaces  630  of the protrusions  416 . 
     Referring to  FIG. 10 , another example of an adjustable column protector  100  is installed on a column  102 . The adjustable column protector includes four corner sections  104  (as is the case in the examples described above) nested within one another such that a portion of the column  102  is fully enveloped by the adjustable column protector  100 . One or more of the corner sections  104  includes a strengthening rib  109  on its outer surface  412 . In general, the strengthening ribs  109  increase the rigidity of the corner sections  104  and provide an alternative aesthetic appearance for the column protector  100 . 
     In some examples the corner sections are made from a plastic material such as high density polyethylene (HDPE). 
     In some examples, a strap tightening tool can be used to tighten the straps  106  and secure the adjustable column protector  100  onto a column  102 . In some examples the adjustable column protector  100  includes recesses for accommodating such a tool during a tightening process. 
     In some examples, all surfaces of the column protector, including surfaces other than the top surface  419  of the bumper  418 , are shaped to ensure that liquids and debris shed off of the column protector. 
     In some examples, the column protector includes an exterior shell that can rotate upon impact in order to further dissipate the force of collisions. 
     In some examples, the column protector includes a proximity sensing alarm for warning equipment operators of an impending collision. 
     In some examples, extender members, each having a substantially planar shape, have an opening configured to receive a protrusion  416  of one of the corner sections  104  and a protrusion configured for insertion into a protrusion receiving slot  420  another of the corner sections  104 . Such planar extender members serve to protect columns or other objects whose dimensions preclude the use of corner sections  104  alone. 
     While the above column protector is described as having only four corner sections  104 , in some examples, a similar design using more or fewer corner sections can be used for other column shapes. 
     It is to be understood that the foregoing description is intended to illustrate and not to limit the scope of the invention, which is defined by the scope of the appended claims. Other embodiments are within the scope of the following claims.